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|
/*
*******************************************************************************
*
* FIFO Generator - Verilog Behavioral Model
*
*******************************************************************************
*
* (c) Copyright 1995 - 2009 Xilinx, Inc. All rights reserved.
*
* This file contains confidential and proprietary information
* of Xilinx, Inc. and is protected under U.S. and
* international copyright and other intellectual property
* laws.
*
* DISCLAIMER
* This disclaimer is not a license and does not grant any
* rights to the materials distributed herewith. Except as
* otherwise provided in a valid license issued to you by
* Xilinx, and to the maximum extent permitted by applicable
* law: (1) THESE MATERIALS ARE MADE AVAILABLE "AS IS" AND
* WITH ALL FAULTS, AND XILINX HEREBY DISCLAIMS ALL WARRANTIES
* AND CONDITIONS, EXPRESS, IMPLIED, OR STATUTORY, INCLUDING
* BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY, NON-
* INFRINGEMENT, OR FITNESS FOR ANY PARTICULAR PURPOSE; and
* (2) Xilinx shall not be liable (whether in contract or tort,
* including negligence, or under any other theory of
* liability) for any loss or damage of any kind or nature
* related to, arising under or in connection with these
* materials, including for any direct, or any indirect,
* special, incidental, or consequential loss or damage
* (including loss of data, profits, goodwill, or any type of
* loss or damage suffered as a result of any action brought
* by a third party) even if such damage or loss was
* reasonably foreseeable or Xilinx had been advised of the
* possibility of the same.
*
* CRITICAL APPLICATIONS
* Xilinx products are not designed or intended to be fail-
* safe, or for use in any application requiring fail-safe
* performance, such as life-support or safety devices or
* systems, Class III medical devices, nuclear facilities,
* applications related to the deployment of airbags, or any
* other applications that could lead to death, personal
* injury, or severe property or environmental damage
* (individually and collectively, "Critical
* Applications"). Customer assumes the sole risk and
* liability of any use of Xilinx products in Critical
* Applications, subject only to applicable laws and
* regulations governing limitations on product liability.
*
* THIS COPYRIGHT NOTICE AND DISCLAIMER MUST BE RETAINED AS
* PART OF THIS FILE AT ALL TIMES.
*
*******************************************************************************
*******************************************************************************
*
* Filename: FIFO_GENERATOR_V6_1.v
*
* Author : Xilinx
*
*******************************************************************************
* Structure:
*
* fifo_generator_v6_1.vhd
* |
* +-fifo_generator_v6_1_bhv_ver_as
* |
* +-fifo_generator_v6_1_bhv_ver_ss
* |
* +-fifo_generator_v6_1_bhv_ver_preload0
*
*******************************************************************************
* Description:
*
* The Verilog behavioral model for the FIFO Generator.
*
* The behavioral model has three parts:
* - The behavioral model for independent clocks FIFOs (_as)
* - The behavioral model for common clock FIFOs (_ss)
* - The "preload logic" block which implements First-word Fall-through
*
*******************************************************************************
* Description:
* The verilog behavioral model for the FIFO generator core.
*
*******************************************************************************
*/
`timescale 1ps/1ps
`ifndef TCQ
`define TCQ 100
`endif
/*******************************************************************************
* Declaration of top-level module
******************************************************************************/
module FIFO_GENERATOR_V6_1
#(
parameter C_COMMON_CLOCK = 0,
parameter C_COUNT_TYPE = 0,
parameter C_DATA_COUNT_WIDTH = 2,
parameter C_DEFAULT_VALUE = "",
parameter C_DIN_WIDTH = 8,
parameter C_DOUT_RST_VAL = "",
parameter C_DOUT_WIDTH = 8,
parameter C_ENABLE_RLOCS = 0,
parameter C_FAMILY = "virtex6", //Not allowed in Verilog model
parameter C_FULL_FLAGS_RST_VAL = 1,
parameter C_HAS_ALMOST_EMPTY = 0,
parameter C_HAS_ALMOST_FULL = 0,
parameter C_HAS_BACKUP = 0,
parameter C_HAS_DATA_COUNT = 0,
parameter C_HAS_INT_CLK = 0,
parameter C_HAS_MEMINIT_FILE = 0,
parameter C_HAS_OVERFLOW = 0,
parameter C_HAS_RD_DATA_COUNT = 0,
parameter C_HAS_RD_RST = 0,
parameter C_HAS_RST = 0,
parameter C_HAS_SRST = 0,
parameter C_HAS_UNDERFLOW = 0,
parameter C_HAS_VALID = 0,
parameter C_HAS_WR_ACK = 0,
parameter C_HAS_WR_DATA_COUNT = 0,
parameter C_HAS_WR_RST = 0,
parameter C_IMPLEMENTATION_TYPE = 0,
parameter C_INIT_WR_PNTR_VAL = 0,
parameter C_MEMORY_TYPE = 1,
parameter C_MIF_FILE_NAME = "",
parameter C_OPTIMIZATION_MODE = 0,
parameter C_OVERFLOW_LOW = 0,
parameter C_PRELOAD_LATENCY = 1,
parameter C_PRELOAD_REGS = 0,
parameter C_PRIM_FIFO_TYPE = "",
parameter C_PROG_EMPTY_THRESH_ASSERT_VAL = 0,
parameter C_PROG_EMPTY_THRESH_NEGATE_VAL = 0,
parameter C_PROG_EMPTY_TYPE = 0,
parameter C_PROG_FULL_THRESH_ASSERT_VAL = 0,
parameter C_PROG_FULL_THRESH_NEGATE_VAL = 0,
parameter C_PROG_FULL_TYPE = 0,
parameter C_RD_DATA_COUNT_WIDTH = 2,
parameter C_RD_DEPTH = 256,
parameter C_RD_FREQ = 1,
parameter C_RD_PNTR_WIDTH = 8,
parameter C_UNDERFLOW_LOW = 0,
parameter C_USE_DOUT_RST = 0,
parameter C_USE_ECC = 0,
parameter C_USE_EMBEDDED_REG = 0,
parameter C_USE_FIFO16_FLAGS = 0,
parameter C_USE_FWFT_DATA_COUNT = 0,
parameter C_VALID_LOW = 0,
parameter C_WR_ACK_LOW = 0,
parameter C_WR_DATA_COUNT_WIDTH = 2,
parameter C_WR_DEPTH = 256,
parameter C_WR_FREQ = 1,
parameter C_WR_PNTR_WIDTH = 8,
parameter C_WR_RESPONSE_LATENCY = 1,
parameter C_MSGON_VAL = 1,
parameter C_ENABLE_RST_SYNC = 1,
parameter C_ERROR_INJECTION_TYPE = 0
)
(
input BACKUP,
input BACKUP_MARKER,
input CLK,
input RST,
input SRST,
input WR_CLK,
input WR_RST,
input RD_CLK,
input RD_RST,
input [C_DIN_WIDTH-1:0] DIN,
input WR_EN,
input RD_EN,
input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH,
input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_ASSERT,
input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_NEGATE,
input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH,
input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_ASSERT,
input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_NEGATE,
input INT_CLK,
input INJECTDBITERR,
input INJECTSBITERR,
output [C_DOUT_WIDTH-1:0] DOUT,
output FULL,
output ALMOST_FULL,
output WR_ACK,
output OVERFLOW,
output EMPTY,
output ALMOST_EMPTY,
output VALID,
output UNDERFLOW,
output [C_DATA_COUNT_WIDTH-1:0] DATA_COUNT,
output [C_RD_DATA_COUNT_WIDTH-1:0] RD_DATA_COUNT,
output [C_WR_DATA_COUNT_WIDTH-1:0] WR_DATA_COUNT,
output PROG_FULL,
output PROG_EMPTY,
output SBITERR,
output DBITERR
);
/*
******************************************************************************
* Definition of Parameters
******************************************************************************
* C_COMMON_CLOCK : Common Clock (1), Independent Clocks (0)
* C_COUNT_TYPE : *not used
* C_DATA_COUNT_WIDTH : Width of DATA_COUNT bus
* C_DEFAULT_VALUE : *not used
* C_DIN_WIDTH : Width of DIN bus
* C_DOUT_RST_VAL : Reset value of DOUT
* C_DOUT_WIDTH : Width of DOUT bus
* C_ENABLE_RLOCS : *not used
* C_FAMILY : not used in bhv model
* C_FULL_FLAGS_RST_VAL : Full flags rst val (0 or 1)
* C_HAS_ALMOST_EMPTY : 1=Core has ALMOST_EMPTY flag
* C_HAS_ALMOST_FULL : 1=Core has ALMOST_FULL flag
* C_HAS_BACKUP : *not used
* C_HAS_DATA_COUNT : 1=Core has DATA_COUNT bus
* C_HAS_INT_CLK : not used in bhv model
* C_HAS_MEMINIT_FILE : *not used
* C_HAS_OVERFLOW : 1=Core has OVERFLOW flag
* C_HAS_RD_DATA_COUNT : 1=Core has RD_DATA_COUNT bus
* C_HAS_RD_RST : *not used
* C_HAS_RST : 1=Core has Async Rst
* C_HAS_SRST : 1=Core has Sync Rst
* C_HAS_UNDERFLOW : 1=Core has UNDERFLOW flag
* C_HAS_VALID : 1=Core has VALID flag
* C_HAS_WR_ACK : 1=Core has WR_ACK flag
* C_HAS_WR_DATA_COUNT : 1=Core has WR_DATA_COUNT bus
* C_HAS_WR_RST : *not used
* C_IMPLEMENTATION_TYPE : 0=Common-Clock Bram/Dram
* 1=Common-Clock ShiftRam
* 2=Indep. Clocks Bram/Dram
* 3=Virtex-4 Built-in
* 4=Virtex-5 Built-in
* C_INIT_WR_PNTR_VAL : *not used
* C_MEMORY_TYPE : 1=Block RAM
* 2=Distributed RAM
* 3=Shift RAM
* 4=Built-in FIFO
* C_MIF_FILE_NAME : *not used
* C_OPTIMIZATION_MODE : *not used
* C_OVERFLOW_LOW : 1=OVERFLOW active low
* C_PRELOAD_LATENCY : Latency of read: 0, 1, 2
* C_PRELOAD_REGS : 1=Use output registers
* C_PRIM_FIFO_TYPE : not used in bhv model
* C_PROG_EMPTY_THRESH_ASSERT_VAL: PROG_EMPTY assert threshold
* C_PROG_EMPTY_THRESH_NEGATE_VAL: PROG_EMPTY negate threshold
* C_PROG_EMPTY_TYPE : 0=No programmable empty
* 1=Single prog empty thresh constant
* 2=Multiple prog empty thresh constants
* 3=Single prog empty thresh input
* 4=Multiple prog empty thresh inputs
* C_PROG_FULL_THRESH_ASSERT_VAL : PROG_FULL assert threshold
* C_PROG_FULL_THRESH_NEGATE_VAL : PROG_FULL negate threshold
* C_PROG_FULL_TYPE : 0=No prog full
* 1=Single prog full thresh constant
* 2=Multiple prog full thresh constants
* 3=Single prog full thresh input
* 4=Multiple prog full thresh inputs
* C_RD_DATA_COUNT_WIDTH : Width of RD_DATA_COUNT bus
* C_RD_DEPTH : Depth of read interface (2^N)
* C_RD_FREQ : not used in bhv model
* C_RD_PNTR_WIDTH : always log2(C_RD_DEPTH)
* C_UNDERFLOW_LOW : 1=UNDERFLOW active low
* C_USE_DOUT_RST : 1=Resets DOUT on RST
* C_USE_ECC : Used for error injection purpose
* C_USE_EMBEDDED_REG : 1=Use BRAM embedded output register
* C_USE_FIFO16_FLAGS : not used in bhv model
* C_USE_FWFT_DATA_COUNT : 1=Use extra logic for FWFT data count
* C_VALID_LOW : 1=VALID active low
* C_WR_ACK_LOW : 1=WR_ACK active low
* C_WR_DATA_COUNT_WIDTH : Width of WR_DATA_COUNT bus
* C_WR_DEPTH : Depth of write interface (2^N)
* C_WR_FREQ : not used in bhv model
* C_WR_PNTR_WIDTH : always log2(C_WR_DEPTH)
* C_WR_RESPONSE_LATENCY : *not used
* C_MSGON_VAL : *not used by bhv model
* C_ENABLE_RST_SYNC : 0 = Use WR_RST & RD_RST
* 1 = Use RST
* C_ERROR_INJECTION_TYPE : 0 = No error injection
* 1 = Single bit error injection only
* 2 = Double bit error injection only
* 3 = Single and double bit error injection
******************************************************************************
* Definition of Ports
******************************************************************************
* BACKUP : Not used
* BACKUP_MARKER: Not used
* CLK : Clock
* DIN : Input data bus
* PROG_EMPTY_THRESH : Threshold for Programmable Empty Flag
* PROG_EMPTY_THRESH_ASSERT: Threshold for Programmable Empty Flag
* PROG_EMPTY_THRESH_NEGATE: Threshold for Programmable Empty Flag
* PROG_FULL_THRESH : Threshold for Programmable Full Flag
* PROG_FULL_THRESH_ASSERT : Threshold for Programmable Full Flag
* PROG_FULL_THRESH_NEGATE : Threshold for Programmable Full Flag
* RD_CLK : Read Domain Clock
* RD_EN : Read enable
* RD_RST : Read Reset
* RST : Asynchronous Reset
* SRST : Synchronous Reset
* WR_CLK : Write Domain Clock
* WR_EN : Write enable
* WR_RST : Write Reset
* INT_CLK : Internal Clock
* INJECTSBITERR: Inject Signle bit error
* INJECTDBITERR: Inject Double bit error
* ALMOST_EMPTY : One word remaining in FIFO
* ALMOST_FULL : One empty space remaining in FIFO
* DATA_COUNT : Number of data words in fifo( synchronous to CLK)
* DOUT : Output data bus
* EMPTY : Empty flag
* FULL : Full flag
* OVERFLOW : Last write rejected
* PROG_EMPTY : Programmable Empty Flag
* PROG_FULL : Programmable Full Flag
* RD_DATA_COUNT: Number of data words in fifo (synchronous to RD_CLK)
* UNDERFLOW : Last read rejected
* VALID : Last read acknowledged, DOUT bus VALID
* WR_ACK : Last write acknowledged
* WR_DATA_COUNT: Number of data words in fifo (synchronous to WR_CLK)
* SBITERR : Single Bit ECC Error Detected
* DBITERR : Double Bit ECC Error Detected
******************************************************************************
*/
/*****************************************************************************
* Derived parameters
****************************************************************************/
//There are 2 Verilog behavioral models
// 0 = Common-Clock FIFO/ShiftRam FIFO
// 1 = Independent Clocks FIFO
parameter C_VERILOG_IMPL = (C_IMPLEMENTATION_TYPE == 2) ? 1 : 0;
//Internal reset signals
reg rd_rst_asreg = 0;
reg rd_rst_asreg_d1 = 0;
reg rd_rst_asreg_d2 = 0;
reg rd_rst_reg = 0;
wire rd_rst_comb;
reg rd_rst_d1 = 0;
reg wr_rst_asreg = 0;
reg wr_rst_asreg_d1 = 0;
reg wr_rst_asreg_d2 = 0;
reg wr_rst_reg = 0;
wire wr_rst_comb;
wire wr_rst_i;
wire rd_rst_i;
wire rst_i;
//Internal reset signals
reg rst_asreg = 0;
reg rst_asreg_d1 = 0;
reg rst_asreg_d2 = 0;
reg rst_reg = 0;
wire rst_comb;
wire rst_full_gen_i;
wire rst_full_ff_i;
wire RD_CLK_P0_IN;
wire RST_P0_IN;
wire RD_EN_FIFO_IN;
wire RD_EN_P0_IN;
wire ALMOST_EMPTY_FIFO_OUT;
wire ALMOST_FULL_FIFO_OUT;
wire [C_DATA_COUNT_WIDTH-1:0] DATA_COUNT_FIFO_OUT;
wire [C_DOUT_WIDTH-1:0] DOUT_FIFO_OUT;
wire EMPTY_FIFO_OUT;
wire FULL_FIFO_OUT;
wire OVERFLOW_FIFO_OUT;
wire PROG_EMPTY_FIFO_OUT;
wire PROG_FULL_FIFO_OUT;
wire VALID_FIFO_OUT;
wire [C_RD_DATA_COUNT_WIDTH-1:0] RD_DATA_COUNT_FIFO_OUT;
wire UNDERFLOW_FIFO_OUT;
wire WR_ACK_FIFO_OUT;
wire [C_WR_DATA_COUNT_WIDTH-1:0] WR_DATA_COUNT_FIFO_OUT;
//***************************************************************************
// Internal Signals
// The core uses either the internal_ wires or the preload0_ wires depending
// on whether the core uses Preload0 or not.
// When using preload0, the internal signals connect the internal core to
// the preload logic, and the external core's interfaces are tied to the
// preload0 signals from the preload logic.
//***************************************************************************
wire [C_DOUT_WIDTH-1:0] DATA_P0_OUT;
wire VALID_P0_OUT;
wire EMPTY_P0_OUT;
wire ALMOSTEMPTY_P0_OUT;
reg EMPTY_P0_OUT_Q;
reg ALMOSTEMPTY_P0_OUT_Q;
wire UNDERFLOW_P0_OUT;
wire RDEN_P0_OUT;
wire [C_DOUT_WIDTH-1:0] DATA_P0_IN;
wire EMPTY_P0_IN;
reg [31:0] DATA_COUNT_FWFT;
reg SS_FWFT_WR ;
reg SS_FWFT_RD ;
wire sbiterr_fifo_out;
wire dbiterr_fifo_out;
// Assign 0 if not selected to avoid 'X' propogation to S/DBITERR.
assign inject_sbit_err = ((C_ERROR_INJECTION_TYPE == 1) || (C_ERROR_INJECTION_TYPE == 3)) ?
INJECTSBITERR : 0;
assign inject_dbit_err = ((C_ERROR_INJECTION_TYPE == 2) || (C_ERROR_INJECTION_TYPE == 3)) ?
INJECTDBITERR : 0;
// Choose the behavioral model to instantiate based on the C_VERILOG_IMPL
// parameter (1=Independent Clocks, 0=Common Clock)
localparam FULL_FLAGS_RST_VAL = (C_HAS_SRST == 1) ? 0 : C_FULL_FLAGS_RST_VAL;
generate
case (C_VERILOG_IMPL)
0 : begin : block1
//Common Clock Behavioral Model
fifo_generator_v6_1_bhv_ver_ss
#(
C_DATA_COUNT_WIDTH,
C_DIN_WIDTH,
C_DOUT_RST_VAL,
C_DOUT_WIDTH,
// C_FULL_FLAGS_RST_VAL,
FULL_FLAGS_RST_VAL,
C_HAS_ALMOST_EMPTY,
C_HAS_ALMOST_FULL,
C_HAS_DATA_COUNT,
C_HAS_OVERFLOW,
C_HAS_RD_DATA_COUNT,
C_HAS_RST,
C_HAS_SRST,
C_HAS_UNDERFLOW,
C_HAS_VALID,
C_HAS_WR_ACK,
C_HAS_WR_DATA_COUNT,
C_IMPLEMENTATION_TYPE,
C_MEMORY_TYPE,
C_OVERFLOW_LOW,
C_PRELOAD_LATENCY,
C_PRELOAD_REGS,
C_PROG_EMPTY_THRESH_ASSERT_VAL,
C_PROG_EMPTY_THRESH_NEGATE_VAL,
C_PROG_EMPTY_TYPE,
C_PROG_FULL_THRESH_ASSERT_VAL,
C_PROG_FULL_THRESH_NEGATE_VAL,
C_PROG_FULL_TYPE,
C_RD_DATA_COUNT_WIDTH,
C_RD_DEPTH,
C_RD_PNTR_WIDTH,
C_UNDERFLOW_LOW,
C_USE_DOUT_RST,
C_USE_EMBEDDED_REG,
C_USE_FWFT_DATA_COUNT,
C_VALID_LOW,
C_WR_ACK_LOW,
C_WR_DATA_COUNT_WIDTH,
C_WR_DEPTH,
C_WR_PNTR_WIDTH,
C_USE_ECC,
C_ENABLE_RST_SYNC,
C_ERROR_INJECTION_TYPE
)
gen_ss
(
.CLK (CLK),
.RST (rst_i),
.SRST (SRST),
.RST_FULL_GEN (rst_full_gen_i),
.RST_FULL_FF (rst_full_ff_i),
.DIN (DIN),
.WR_EN (WR_EN),
.RD_EN (RD_EN_FIFO_IN),
.PROG_EMPTY_THRESH (PROG_EMPTY_THRESH),
.PROG_EMPTY_THRESH_ASSERT (PROG_EMPTY_THRESH_ASSERT),
.PROG_EMPTY_THRESH_NEGATE (PROG_EMPTY_THRESH_NEGATE),
.PROG_FULL_THRESH (PROG_FULL_THRESH),
.PROG_FULL_THRESH_ASSERT (PROG_FULL_THRESH_ASSERT),
.PROG_FULL_THRESH_NEGATE (PROG_FULL_THRESH_NEGATE),
.INJECTSBITERR (inject_sbit_err),
.INJECTDBITERR (inject_dbit_err),
.DOUT (DOUT_FIFO_OUT),
.FULL (FULL_FIFO_OUT),
.ALMOST_FULL (ALMOST_FULL_FIFO_OUT),
.WR_ACK (WR_ACK_FIFO_OUT),
.OVERFLOW (OVERFLOW_FIFO_OUT),
.EMPTY (EMPTY_FIFO_OUT),
.ALMOST_EMPTY (ALMOST_EMPTY_FIFO_OUT),
.VALID (VALID_FIFO_OUT),
.UNDERFLOW (UNDERFLOW_FIFO_OUT),
.DATA_COUNT (DATA_COUNT_FIFO_OUT),
.PROG_FULL (PROG_FULL_FIFO_OUT),
.PROG_EMPTY (PROG_EMPTY_FIFO_OUT),
.SBITERR (sbiterr_fifo_out),
.DBITERR (dbiterr_fifo_out)
);
end
1 : begin : block1
//Independent Clocks Behavioral Model
fifo_generator_v6_1_bhv_ver_as
#(
C_DATA_COUNT_WIDTH,
C_DIN_WIDTH,
C_DOUT_RST_VAL,
C_DOUT_WIDTH,
C_FULL_FLAGS_RST_VAL,
C_HAS_ALMOST_EMPTY,
C_HAS_ALMOST_FULL,
C_HAS_DATA_COUNT,
C_HAS_OVERFLOW,
C_HAS_RD_DATA_COUNT,
C_HAS_RST,
C_HAS_UNDERFLOW,
C_HAS_VALID,
C_HAS_WR_ACK,
C_HAS_WR_DATA_COUNT,
C_IMPLEMENTATION_TYPE,
C_MEMORY_TYPE,
C_OVERFLOW_LOW,
C_PRELOAD_LATENCY,
C_PRELOAD_REGS,
C_PROG_EMPTY_THRESH_ASSERT_VAL,
C_PROG_EMPTY_THRESH_NEGATE_VAL,
C_PROG_EMPTY_TYPE,
C_PROG_FULL_THRESH_ASSERT_VAL,
C_PROG_FULL_THRESH_NEGATE_VAL,
C_PROG_FULL_TYPE,
C_RD_DATA_COUNT_WIDTH,
C_RD_DEPTH,
C_RD_PNTR_WIDTH,
C_UNDERFLOW_LOW,
C_USE_DOUT_RST,
C_USE_EMBEDDED_REG,
C_USE_FWFT_DATA_COUNT,
C_VALID_LOW,
C_WR_ACK_LOW,
C_WR_DATA_COUNT_WIDTH,
C_WR_DEPTH,
C_WR_PNTR_WIDTH,
C_USE_ECC,
C_ENABLE_RST_SYNC,
C_ERROR_INJECTION_TYPE
)
gen_as
(
.WR_CLK (WR_CLK),
.RD_CLK (RD_CLK),
.RST (rst_i),
.RST_FULL_GEN (rst_full_gen_i),
.RST_FULL_FF (rst_full_ff_i),
.WR_RST (wr_rst_i),
.RD_RST (rd_rst_i),
.DIN (DIN),
.WR_EN (WR_EN),
.RD_EN (RD_EN_FIFO_IN),
.RD_EN_USER (RD_EN),
.PROG_EMPTY_THRESH (PROG_EMPTY_THRESH),
.PROG_EMPTY_THRESH_ASSERT (PROG_EMPTY_THRESH_ASSERT),
.PROG_EMPTY_THRESH_NEGATE (PROG_EMPTY_THRESH_NEGATE),
.PROG_FULL_THRESH (PROG_FULL_THRESH),
.PROG_FULL_THRESH_ASSERT (PROG_FULL_THRESH_ASSERT),
.PROG_FULL_THRESH_NEGATE (PROG_FULL_THRESH_NEGATE),
.INJECTSBITERR (inject_sbit_err),
.INJECTDBITERR (inject_dbit_err),
.USER_EMPTY_FB (EMPTY_P0_OUT),
.DOUT (DOUT_FIFO_OUT),
.FULL (FULL_FIFO_OUT),
.ALMOST_FULL (ALMOST_FULL_FIFO_OUT),
.WR_ACK (WR_ACK_FIFO_OUT),
.OVERFLOW (OVERFLOW_FIFO_OUT),
.EMPTY (EMPTY_FIFO_OUT),
.ALMOST_EMPTY (ALMOST_EMPTY_FIFO_OUT),
.VALID (VALID_FIFO_OUT),
.UNDERFLOW (UNDERFLOW_FIFO_OUT),
.RD_DATA_COUNT (RD_DATA_COUNT_FIFO_OUT),
.WR_DATA_COUNT (WR_DATA_COUNT_FIFO_OUT),
.PROG_FULL (PROG_FULL_FIFO_OUT),
.PROG_EMPTY (PROG_EMPTY_FIFO_OUT),
.SBITERR (sbiterr_fifo_out),
.DBITERR (dbiterr_fifo_out)
);
end
default : begin : block1
//Independent Clocks Behavioral Model
fifo_generator_v6_1_bhv_ver_as
#(
C_DATA_COUNT_WIDTH,
C_DIN_WIDTH,
C_DOUT_RST_VAL,
C_DOUT_WIDTH,
C_FULL_FLAGS_RST_VAL,
C_HAS_ALMOST_EMPTY,
C_HAS_ALMOST_FULL,
C_HAS_DATA_COUNT,
C_HAS_OVERFLOW,
C_HAS_RD_DATA_COUNT,
C_HAS_RST,
C_HAS_UNDERFLOW,
C_HAS_VALID,
C_HAS_WR_ACK,
C_HAS_WR_DATA_COUNT,
C_IMPLEMENTATION_TYPE,
C_MEMORY_TYPE,
C_OVERFLOW_LOW,
C_PRELOAD_LATENCY,
C_PRELOAD_REGS,
C_PROG_EMPTY_THRESH_ASSERT_VAL,
C_PROG_EMPTY_THRESH_NEGATE_VAL,
C_PROG_EMPTY_TYPE,
C_PROG_FULL_THRESH_ASSERT_VAL,
C_PROG_FULL_THRESH_NEGATE_VAL,
C_PROG_FULL_TYPE,
C_RD_DATA_COUNT_WIDTH,
C_RD_DEPTH,
C_RD_PNTR_WIDTH,
C_UNDERFLOW_LOW,
C_USE_DOUT_RST,
C_USE_EMBEDDED_REG,
C_USE_FWFT_DATA_COUNT,
C_VALID_LOW,
C_WR_ACK_LOW,
C_WR_DATA_COUNT_WIDTH,
C_WR_DEPTH,
C_WR_PNTR_WIDTH,
C_USE_ECC,
C_ENABLE_RST_SYNC,
C_ERROR_INJECTION_TYPE
)
gen_as
(
.WR_CLK (WR_CLK),
.RD_CLK (RD_CLK),
.RST (rst_i),
.RST_FULL_GEN (rst_full_gen_i),
.RST_FULL_FF (rst_full_ff_i),
.WR_RST (wr_rst_i),
.RD_RST (rd_rst_i),
.DIN (DIN),
.WR_EN (WR_EN),
.RD_EN (RD_EN_FIFO_IN),
.RD_EN_USER (RD_EN),
.PROG_EMPTY_THRESH (PROG_EMPTY_THRESH),
.PROG_EMPTY_THRESH_ASSERT (PROG_EMPTY_THRESH_ASSERT),
.PROG_EMPTY_THRESH_NEGATE (PROG_EMPTY_THRESH_NEGATE),
.PROG_FULL_THRESH (PROG_FULL_THRESH),
.PROG_FULL_THRESH_ASSERT (PROG_FULL_THRESH_ASSERT),
.PROG_FULL_THRESH_NEGATE (PROG_FULL_THRESH_NEGATE),
.INJECTSBITERR (inject_sbit_err),
.INJECTDBITERR (inject_dbit_err),
.USER_EMPTY_FB (EMPTY_P0_OUT),
.DOUT (DOUT_FIFO_OUT),
.FULL (FULL_FIFO_OUT),
.ALMOST_FULL (ALMOST_FULL_FIFO_OUT),
.WR_ACK (WR_ACK_FIFO_OUT),
.OVERFLOW (OVERFLOW_FIFO_OUT),
.EMPTY (EMPTY_FIFO_OUT),
.ALMOST_EMPTY (ALMOST_EMPTY_FIFO_OUT),
.VALID (VALID_FIFO_OUT),
.UNDERFLOW (UNDERFLOW_FIFO_OUT),
.RD_DATA_COUNT (RD_DATA_COUNT_FIFO_OUT),
.WR_DATA_COUNT (WR_DATA_COUNT_FIFO_OUT),
.PROG_FULL (PROG_FULL_FIFO_OUT),
.PROG_EMPTY (PROG_EMPTY_FIFO_OUT),
.SBITERR (sbiterr_fifo_out),
.DBITERR (dbiterr_fifo_out)
);
end
endcase
endgenerate
//**************************************************************************
// Connect Internal Signals
// (Signals labeled internal_*)
// In the normal case, these signals tie directly to the FIFO's inputs and
// outputs.
// In the case of Preload Latency 0 or 1, there are intermediate
// signals between the internal FIFO and the preload logic.
//**************************************************************************
//***********************************************
// If First-Word Fall-Through, instantiate
// the preload0 (FWFT) module
//***********************************************
generate
if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin : block2
fifo_generator_v6_1_bhv_ver_preload0
#(
C_DOUT_RST_VAL,
C_DOUT_WIDTH,
C_HAS_RST,
C_ENABLE_RST_SYNC,
C_HAS_SRST,
C_USE_DOUT_RST,
C_USE_ECC,
C_VALID_LOW,
C_UNDERFLOW_LOW,
C_MEMORY_TYPE
)
fgpl0
(
.RD_CLK (RD_CLK_P0_IN),
.RD_RST (RST_P0_IN),
.SRST (SRST),
.RD_EN (RD_EN_P0_IN),
.FIFOEMPTY (EMPTY_P0_IN),
.FIFODATA (DATA_P0_IN),
.FIFOSBITERR (sbiterr_fifo_out),
.FIFODBITERR (dbiterr_fifo_out),
.USERDATA (DATA_P0_OUT),
.USERVALID (VALID_P0_OUT),
.USEREMPTY (EMPTY_P0_OUT),
.USERALMOSTEMPTY (ALMOSTEMPTY_P0_OUT),
.USERUNDERFLOW (UNDERFLOW_P0_OUT),
.RAMVALID (RAMVALID_P0_OUT),
.FIFORDEN (RDEN_P0_OUT),
.USERSBITERR (SBITERR),
.USERDBITERR (DBITERR)
);
//***********************************************
// Connect inputs to preload (FWFT) module
//***********************************************
//Connect the RD_CLK of the Preload (FWFT) module to CLK if we
// have a common-clock FIFO, or RD_CLK if we have an
// independent clock FIFO
assign RD_CLK_P0_IN = ((C_VERILOG_IMPL == 0) ? CLK : RD_CLK);
assign RST_P0_IN = (C_COMMON_CLOCK == 0) ? rd_rst_i : (C_HAS_RST == 1) ? rst_i : 0;
assign RD_EN_P0_IN = RD_EN;
assign EMPTY_P0_IN = EMPTY_FIFO_OUT;
assign DATA_P0_IN = DOUT_FIFO_OUT;
//***********************************************
// Connect outputs from preload (FWFT) module
//***********************************************
assign DOUT = DATA_P0_OUT;
assign VALID = VALID_P0_OUT ;
assign EMPTY = EMPTY_P0_OUT;
assign ALMOST_EMPTY = ALMOSTEMPTY_P0_OUT;
assign UNDERFLOW = UNDERFLOW_P0_OUT ;
assign RD_EN_FIFO_IN = RDEN_P0_OUT;
//***********************************************
// Create DATA_COUNT from First-Word Fall-Through
// data count
//***********************************************
assign DATA_COUNT = (C_USE_FWFT_DATA_COUNT == 0)? DATA_COUNT_FIFO_OUT:
(C_DATA_COUNT_WIDTH>C_RD_PNTR_WIDTH) ? DATA_COUNT_FWFT[C_RD_PNTR_WIDTH:0] :
DATA_COUNT_FWFT[C_RD_PNTR_WIDTH:C_RD_PNTR_WIDTH-C_DATA_COUNT_WIDTH+1];
//***********************************************
// Create DATA_COUNT from First-Word Fall-Through
// data count
//***********************************************
always @ (posedge RD_CLK or posedge RST_P0_IN) begin
if (RST_P0_IN) begin
EMPTY_P0_OUT_Q <= #`TCQ 1;
ALMOSTEMPTY_P0_OUT_Q <= #`TCQ 1;
end else begin
EMPTY_P0_OUT_Q <= #`TCQ EMPTY_P0_OUT;
ALMOSTEMPTY_P0_OUT_Q <= #`TCQ ALMOSTEMPTY_P0_OUT;
end
end //always
//***********************************************
// logic for common-clock data count when FWFT is selected
//***********************************************
initial begin
SS_FWFT_RD = 1'b0;
DATA_COUNT_FWFT = 0 ;
SS_FWFT_WR = 1'b0 ;
end //initial
//***********************************************
// common-clock data count is implemented as an
// up-down counter. SS_FWFT_WR and SS_FWFT_RD
// are the up/down enables for the counter.
//***********************************************
always @ (RD_EN or VALID_P0_OUT or WR_EN or FULL_FIFO_OUT) begin
if (C_VALID_LOW == 1) begin
SS_FWFT_RD = RD_EN && ~VALID_P0_OUT ;
end else begin
SS_FWFT_RD = RD_EN && VALID_P0_OUT ;
end
SS_FWFT_WR = (WR_EN && (~FULL_FIFO_OUT)) ;
end
//***********************************************
// common-clock data count is implemented as an
// up-down counter for FWFT. This always block
// calculates the counter.
//***********************************************
always @ (posedge RD_CLK_P0_IN or posedge RST_P0_IN) begin
if (RST_P0_IN) begin
DATA_COUNT_FWFT <= #`TCQ 0;
end else begin
if (SRST && (C_HAS_SRST == 1) ) begin
DATA_COUNT_FWFT <= #`TCQ 0;
end else begin
case ( {SS_FWFT_WR, SS_FWFT_RD})
2'b00: DATA_COUNT_FWFT <= #`TCQ DATA_COUNT_FWFT ;
2'b01: DATA_COUNT_FWFT <= #`TCQ DATA_COUNT_FWFT - 1 ;
2'b10: DATA_COUNT_FWFT <= #`TCQ DATA_COUNT_FWFT + 1 ;
2'b11: DATA_COUNT_FWFT <= #`TCQ DATA_COUNT_FWFT ;
endcase
end //if SRST
end //IF RST
end //always
end else begin : block2 //if !(C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0)
//***********************************************
// If NOT First-Word Fall-Through, wire the outputs
// of the internal _ss or _as FIFO directly to the
// output, and do not instantiate the preload0
// module.
//***********************************************
assign RD_CLK_P0_IN = 0;
assign RST_P0_IN = 0;
assign RD_EN_P0_IN = 0;
assign RD_EN_FIFO_IN = RD_EN;
assign DOUT = DOUT_FIFO_OUT;
assign DATA_P0_IN = 0;
assign VALID = VALID_FIFO_OUT;
assign EMPTY = EMPTY_FIFO_OUT;
assign ALMOST_EMPTY = ALMOST_EMPTY_FIFO_OUT;
assign EMPTY_P0_IN = 0;
assign UNDERFLOW = UNDERFLOW_FIFO_OUT;
assign DATA_COUNT = DATA_COUNT_FIFO_OUT;
assign SBITERR = sbiterr_fifo_out;
assign DBITERR = dbiterr_fifo_out;
end //if !(C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0)
endgenerate
//***********************************************
// Connect user flags to internal signals
//***********************************************
//If we are using extra logic for the FWFT data count, then override the
//RD_DATA_COUNT output when we are EMPTY or ALMOST_EMPTY.
//RD_DATA_COUNT is 0 when EMPTY and 1 when ALMOST_EMPTY.
generate
if (C_USE_FWFT_DATA_COUNT==1 && (C_RD_DATA_COUNT_WIDTH>C_RD_PNTR_WIDTH) ) begin : block3
assign RD_DATA_COUNT = (EMPTY_P0_OUT_Q | RST_P0_IN) ? 0 : (ALMOSTEMPTY_P0_OUT_Q ? 1 : RD_DATA_COUNT_FIFO_OUT);
end //block3
endgenerate
//If we are using extra logic for the FWFT data count, then override the
//RD_DATA_COUNT output when we are EMPTY or ALMOST_EMPTY.
//Due to asymmetric ports, RD_DATA_COUNT is 0 when EMPTY or ALMOST_EMPTY.
generate
if (C_USE_FWFT_DATA_COUNT==1 && (C_RD_DATA_COUNT_WIDTH <=C_RD_PNTR_WIDTH) ) begin : block30
assign RD_DATA_COUNT = (EMPTY_P0_OUT_Q | RST_P0_IN) ? 0 : (ALMOSTEMPTY_P0_OUT_Q ? 0 : RD_DATA_COUNT_FIFO_OUT);
end //block30
endgenerate
//If we are not using extra logic for the FWFT data count,
//then connect RD_DATA_COUNT to the RD_DATA_COUNT from the
//internal FIFO instance
generate
if (C_USE_FWFT_DATA_COUNT==0 ) begin : block31
assign RD_DATA_COUNT = RD_DATA_COUNT_FIFO_OUT;
end
endgenerate
//Always connect WR_DATA_COUNT to the WR_DATA_COUNT from the internal
//FIFO instance
generate
if (C_USE_FWFT_DATA_COUNT==1) begin : block4
assign WR_DATA_COUNT = WR_DATA_COUNT_FIFO_OUT;
end
else begin : block4
assign WR_DATA_COUNT = WR_DATA_COUNT_FIFO_OUT;
end
endgenerate
//Connect other flags to the internal FIFO instance
assign FULL = FULL_FIFO_OUT;
assign ALMOST_FULL = ALMOST_FULL_FIFO_OUT;
assign WR_ACK = WR_ACK_FIFO_OUT;
assign OVERFLOW = OVERFLOW_FIFO_OUT;
assign PROG_FULL = PROG_FULL_FIFO_OUT;
assign PROG_EMPTY = PROG_EMPTY_FIFO_OUT;
// if an asynchronous FIFO has been selected, display a message that the FIFO
// will not be cycle-accurate in simulation
initial begin
if (C_IMPLEMENTATION_TYPE == 2) begin
$display("WARNING: Behavioral models for independent clock FIFO configurations are not cycle-accurate. You may wish to choose the structural simulation model instead of the behavioral model. This will ensure accurate behavior and latencies during simulation. You can enable this from CORE Generator by selecting Project -> Project Options -> Generation tab -> Structural Simulation. See the FIFO Generator User Guide for more information.");
end else if (C_MEMORY_TYPE == 4) begin
$display("FAILURE : Behavioral models for Virtex-4, Virtex-5 and Virtex-6 built-in FIFO configurations is currently not supported. Please select the structural simulation model option in CORE Generator. You can enable this in CORE Generator by selecting Project -> Project Options -> Generation tab -> Structural Simulation. See the FIFO Generator User Guide for more information.");
$finish;
end
end //initial
/**************************************************************************
* Internal reset logic
**************************************************************************/
assign wr_rst_i = (C_HAS_RST == 1 || C_ENABLE_RST_SYNC == 0) ? wr_rst_reg : 0;
assign rd_rst_i = (C_HAS_RST == 1 || C_ENABLE_RST_SYNC == 0) ? rd_rst_reg : 0;
assign rst_i = C_HAS_RST ? rst_reg : 0;
wire rst_2_sync;
wire clk_2_sync = (C_COMMON_CLOCK == 1) ? CLK : WR_CLK;
generate
if (C_ENABLE_RST_SYNC == 0) begin : gnrst_sync
always @* begin
wr_rst_reg <= WR_RST;
rd_rst_reg <= RD_RST;
rst_reg <= 1'b0;
end
assign rst_2_sync = WR_RST;
end else if (C_HAS_RST == 1 && C_COMMON_CLOCK == 0) begin : gic_rst
assign wr_rst_comb = !wr_rst_asreg_d2 && wr_rst_asreg;
assign rd_rst_comb = !rd_rst_asreg_d2 && rd_rst_asreg;
assign rst_2_sync = RST;
always @(posedge WR_CLK or posedge RST) begin
if (RST == 1'b1) begin
wr_rst_asreg <= #`TCQ 1'b1;
end else begin
if (wr_rst_asreg_d1 == 1'b1) begin
wr_rst_asreg <= #`TCQ 1'b0;
end else begin
wr_rst_asreg <= #`TCQ wr_rst_asreg;
end
end
end
always @(posedge WR_CLK) begin
wr_rst_asreg_d1 <= #`TCQ wr_rst_asreg;
wr_rst_asreg_d2 <= #`TCQ wr_rst_asreg_d1;
end
always @(posedge WR_CLK or posedge wr_rst_comb) begin
if (wr_rst_comb == 1'b1) begin
wr_rst_reg <= #`TCQ 1'b1;
end else begin
wr_rst_reg <= #`TCQ 1'b0;
end
end
always @(posedge RD_CLK or posedge RST) begin
if (RST == 1'b1) begin
rd_rst_asreg <= #`TCQ 1'b1;
end else begin
if (rd_rst_asreg_d1 == 1'b1) begin
rd_rst_asreg <= #`TCQ 1'b0;
end else begin
rd_rst_asreg <= #`TCQ rd_rst_asreg;
end
end
end
always @(posedge RD_CLK) begin
rd_rst_asreg_d1 <= #`TCQ rd_rst_asreg;
rd_rst_asreg_d2 <= #`TCQ rd_rst_asreg_d1;
end
always @(posedge RD_CLK or posedge rd_rst_comb) begin
if (rd_rst_comb == 1'b1) begin
rd_rst_reg <= #`TCQ 1'b1;
end else begin
rd_rst_reg <= #`TCQ 1'b0;
end
end
end else if (C_HAS_RST == 1 && C_COMMON_CLOCK == 1) begin : gcc_rst
assign rst_comb = !rst_asreg_d2 && rst_asreg;
assign rst_2_sync = RST;
always @(posedge CLK or posedge RST) begin
if (RST == 1'b1) begin
rst_asreg <= #`TCQ 1'b1;
end else begin
if (rst_asreg_d1 == 1'b1) begin
rst_asreg <= #`TCQ 1'b0;
end else begin
rst_asreg <= #`TCQ rst_asreg;
end
end
end
always @(posedge CLK) begin
rst_asreg_d1 <= #`TCQ rst_asreg;
rst_asreg_d2 <= #`TCQ rst_asreg_d1;
end
always @(posedge CLK or posedge rst_comb) begin
if (rst_comb == 1'b1) begin
rst_reg <= #`TCQ 1'b1;
end else begin
rst_reg <= #`TCQ 1'b0;
end
end
end
endgenerate
reg rst_d1 = 1'b0;
reg rst_d2 = 1'b0;
reg rst_d3 = 1'b0;
reg rst_d4 = 1'b0;
generate
if ((C_HAS_RST == 1 || C_HAS_SRST == 1 || C_ENABLE_RST_SYNC == 0) && C_FULL_FLAGS_RST_VAL == 1) begin : grstd1
// RST_FULL_GEN replaces the reset falling edge detection used to de-assert
// FULL, ALMOST_FULL & PROG_FULL flags if C_FULL_FLAGS_RST_VAL = 1.
// RST_FULL_FF goes to the reset pin of the final flop of FULL, ALMOST_FULL &
// PROG_FULL
always @ (posedge rst_2_sync or posedge clk_2_sync) begin
if (rst_2_sync) begin
rst_d1 <= 1'b1;
rst_d2 <= 1'b1;
rst_d3 <= 1'b1;
rst_d4 <= 1'b0;
end else begin
if (SRST) begin
rst_d1 <= #`TCQ 1'b1;
rst_d2 <= #`TCQ 1'b1;
rst_d3 <= #`TCQ 1'b1;
rst_d4 <= #`TCQ 1'b0;
end else begin
rst_d1 <= #`TCQ 1'b0;
rst_d2 <= #`TCQ rst_d1;
rst_d3 <= #`TCQ rst_d2;
rst_d4 <= #`TCQ rst_d3;
end
end
end
assign rst_full_ff_i = (C_HAS_SRST == 0) ? rst_d2 : 1'b0 ;
assign rst_full_gen_i = rst_d4;
end else if ((C_HAS_RST == 1 || C_HAS_SRST == 1 || C_ENABLE_RST_SYNC == 0) && C_FULL_FLAGS_RST_VAL == 0) begin : gnrst_full
assign rst_full_gen_i = 1'b0;
assign rst_full_ff_i = (C_COMMON_CLOCK == 0) ? wr_rst_i : rst_i;
end
endgenerate
endmodule //FIFO_GENERATOR_V6_1
/*******************************************************************************
* Declaration of Independent-Clocks FIFO Module
******************************************************************************/
module fifo_generator_v6_1_bhv_ver_as
/***************************************************************************
* Declare user parameters and their defaults
***************************************************************************/
#(
parameter C_DATA_COUNT_WIDTH = 2,
parameter C_DIN_WIDTH = 8,
parameter C_DOUT_RST_VAL = "",
parameter C_DOUT_WIDTH = 8,
parameter C_FULL_FLAGS_RST_VAL = 1,
parameter C_HAS_ALMOST_EMPTY = 0,
parameter C_HAS_ALMOST_FULL = 0,
parameter C_HAS_DATA_COUNT = 0,
parameter C_HAS_OVERFLOW = 0,
parameter C_HAS_RD_DATA_COUNT = 0,
parameter C_HAS_RST = 0,
parameter C_HAS_UNDERFLOW = 0,
parameter C_HAS_VALID = 0,
parameter C_HAS_WR_ACK = 0,
parameter C_HAS_WR_DATA_COUNT = 0,
parameter C_IMPLEMENTATION_TYPE = 0,
parameter C_MEMORY_TYPE = 1,
parameter C_OVERFLOW_LOW = 0,
parameter C_PRELOAD_LATENCY = 1,
parameter C_PRELOAD_REGS = 0,
parameter C_PROG_EMPTY_THRESH_ASSERT_VAL = 0,
parameter C_PROG_EMPTY_THRESH_NEGATE_VAL = 0,
parameter C_PROG_EMPTY_TYPE = 0,
parameter C_PROG_FULL_THRESH_ASSERT_VAL = 0,
parameter C_PROG_FULL_THRESH_NEGATE_VAL = 0,
parameter C_PROG_FULL_TYPE = 0,
parameter C_RD_DATA_COUNT_WIDTH = 2,
parameter C_RD_DEPTH = 256,
parameter C_RD_PNTR_WIDTH = 8,
parameter C_UNDERFLOW_LOW = 0,
parameter C_USE_DOUT_RST = 0,
parameter C_USE_EMBEDDED_REG = 0,
parameter C_USE_FWFT_DATA_COUNT = 0,
parameter C_VALID_LOW = 0,
parameter C_WR_ACK_LOW = 0,
parameter C_WR_DATA_COUNT_WIDTH = 2,
parameter C_WR_DEPTH = 256,
parameter C_WR_PNTR_WIDTH = 8,
parameter C_USE_ECC = 0,
parameter C_ENABLE_RST_SYNC = 1,
parameter C_ERROR_INJECTION_TYPE = 0
)
/***************************************************************************
* Declare Input and Output Ports
***************************************************************************/
(
input [C_DIN_WIDTH-1:0] DIN,
input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH,
input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_ASSERT,
input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_NEGATE,
input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH,
input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_ASSERT,
input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_NEGATE,
input RD_CLK,
input RD_EN,
input RD_EN_USER,
input RST,
input RST_FULL_GEN,
input RST_FULL_FF,
input WR_RST,
input RD_RST,
input WR_CLK,
input WR_EN,
input INJECTDBITERR,
input INJECTSBITERR,
input USER_EMPTY_FB,
output reg ALMOST_EMPTY = 1'b1,
output reg ALMOST_FULL = C_FULL_FLAGS_RST_VAL,
output [C_DOUT_WIDTH-1:0] DOUT,
output reg EMPTY = 1'b1,
output reg FULL = C_FULL_FLAGS_RST_VAL,
output OVERFLOW,
output PROG_EMPTY,
output PROG_FULL,
output VALID,
output [C_RD_DATA_COUNT_WIDTH-1:0] RD_DATA_COUNT,
output UNDERFLOW,
output WR_ACK,
output [C_WR_DATA_COUNT_WIDTH-1:0] WR_DATA_COUNT,
output SBITERR,
output DBITERR
);
reg [C_RD_PNTR_WIDTH:0] rd_data_count_int = 0;
reg [C_WR_PNTR_WIDTH:0] wr_data_count_int = 0;
reg [C_WR_PNTR_WIDTH:0] wdc_fwft_ext_as = 0;
/***************************************************************************
* Parameters used as constants
**************************************************************************/
//When RST is present, set FULL reset value to '1'.
//If core has no RST, make sure FULL powers-on as '0'.
parameter C_DEPTH_RATIO_WR =
(C_WR_DEPTH>C_RD_DEPTH) ? (C_WR_DEPTH/C_RD_DEPTH) : 1;
parameter C_DEPTH_RATIO_RD =
(C_RD_DEPTH>C_WR_DEPTH) ? (C_RD_DEPTH/C_WR_DEPTH) : 1;
parameter C_FIFO_WR_DEPTH = C_WR_DEPTH - 1;
parameter C_FIFO_RD_DEPTH = C_RD_DEPTH - 1;
// C_DEPTH_RATIO_WR | C_DEPTH_RATIO_RD | C_PNTR_WIDTH | EXTRA_WORDS_DC
// -----------------|------------------|-----------------|---------------
// 1 | 8 | C_RD_PNTR_WIDTH | 2
// 1 | 4 | C_RD_PNTR_WIDTH | 2
// 1 | 2 | C_RD_PNTR_WIDTH | 2
// 1 | 1 | C_WR_PNTR_WIDTH | 2
// 2 | 1 | C_WR_PNTR_WIDTH | 4
// 4 | 1 | C_WR_PNTR_WIDTH | 8
// 8 | 1 | C_WR_PNTR_WIDTH | 16
localparam C_PNTR_WIDTH = (C_WR_PNTR_WIDTH>=C_RD_PNTR_WIDTH) ? C_WR_PNTR_WIDTH : C_RD_PNTR_WIDTH;
wire [C_PNTR_WIDTH:0] EXTRA_WORDS_DC = (C_DEPTH_RATIO_WR == 1) ? 2 : (2 * C_DEPTH_RATIO_WR/C_DEPTH_RATIO_RD);
parameter [31:0] reads_per_write = C_DIN_WIDTH/C_DOUT_WIDTH;
parameter [31:0] log2_reads_per_write = log2_val(reads_per_write);
parameter [31:0] writes_per_read = C_DOUT_WIDTH/C_DIN_WIDTH;
parameter [31:0] log2_writes_per_read = log2_val(writes_per_read);
/**************************************************************************
* FIFO Contents Tracking and Data Count Calculations
*************************************************************************/
// Memory which will be used to simulate a FIFO
reg [C_DIN_WIDTH-1:0] memory[C_WR_DEPTH-1:0];
// Local parameters used to determine whether to inject ECC error or not
localparam SYMMETRIC_PORT = (C_DIN_WIDTH == C_DOUT_WIDTH) ? 1 : 0;
localparam ERR_INJECTION = (C_ERROR_INJECTION_TYPE != 0) ? 1 : 0;
localparam ENABLE_ERR_INJECTION = C_USE_ECC && SYMMETRIC_PORT && ERR_INJECTION;
// Array that holds the error injection type (single/double bit error) on
// a specific write operation, which is returned on read to corrupt the
// output data.
reg [1:0] ecc_err[C_WR_DEPTH-1:0];
//The amount of data stored in the FIFO at any time is given
// by num_wr_bits (in the WR_CLK domain) and num_rd_bits (in the RD_CLK
// domain.
//num_wr_bits is calculated by considering the total words in the FIFO,
// and the state of the read pointer (which may not have yet crossed clock
// domains.)
//num_rd_bits is calculated by considering the total words in the FIFO,
// and the state of the write pointer (which may not have yet crossed clock
// domains.)
reg [31:0] num_wr_bits;
reg [31:0] num_rd_bits;
reg [31:0] next_num_wr_bits;
reg [31:0] next_num_rd_bits;
//The write pointer - tracks write operations
// (Works opposite to core: wr_ptr is a DOWN counter)
reg [31:0] wr_ptr;
reg [C_WR_PNTR_WIDTH-1:0] wr_pntr = 0; // UP counter: Rolls back to 0 when reaches to max value.
reg [C_WR_PNTR_WIDTH-1:0] wr_pntr_rd1 = 0;
reg [C_WR_PNTR_WIDTH-1:0] wr_pntr_rd2 = 0;
reg [C_WR_PNTR_WIDTH-1:0] wr_pntr_rd3 = 0;
wire [C_RD_PNTR_WIDTH-1:0] adj_wr_pntr_rd;
reg [C_WR_PNTR_WIDTH-1:0] wr_pntr_rd = 0;
wire wr_rst_i = WR_RST;
reg wr_rst_d1 =0;
//The read pointer - tracks read operations
// (rd_ptr Works opposite to core: rd_ptr is a DOWN counter)
reg [31:0] rd_ptr;
reg [C_RD_PNTR_WIDTH-1:0] rd_pntr = 0; // UP counter: Rolls back to 0 when reaches to max value.
reg [C_RD_PNTR_WIDTH-1:0] rd_pntr_wr1 = 0;
reg [C_RD_PNTR_WIDTH-1:0] rd_pntr_wr2 = 0;
reg [C_RD_PNTR_WIDTH-1:0] rd_pntr_wr3 = 0;
reg [C_RD_PNTR_WIDTH-1:0] rd_pntr_wr4 = 0;
wire [C_WR_PNTR_WIDTH-1:0] adj_rd_pntr_wr;
reg [C_RD_PNTR_WIDTH-1:0] rd_pntr_wr = 0;
wire rd_rst_i = RD_RST;
wire ram_rd_en;
reg ram_rd_en_d1 = 1'b0;
// Delayed ram_rd_en is needed only for STD Embedded register option
generate
if (C_PRELOAD_LATENCY == 2) begin : grd_d
always @ (posedge RD_CLK or posedge rd_rst_i) begin
if (rd_rst_i)
ram_rd_en_d1 <= #`TCQ 1'b0;
else
ram_rd_en_d1 <= #`TCQ ram_rd_en;
end
end
endgenerate
// Write pointer adjustment based on pointers width for EMPTY/ALMOST_EMPTY generation
generate
if (C_RD_PNTR_WIDTH > C_WR_PNTR_WIDTH) begin : rdg // Read depth greater than write depth
assign adj_wr_pntr_rd[C_RD_PNTR_WIDTH-1:C_RD_PNTR_WIDTH-C_WR_PNTR_WIDTH] = wr_pntr_rd;
assign adj_wr_pntr_rd[C_RD_PNTR_WIDTH-C_WR_PNTR_WIDTH-1:0] = 0;
end else begin : rdl // Read depth lesser than or equal to write depth
assign adj_wr_pntr_rd = wr_pntr_rd[C_WR_PNTR_WIDTH-1:C_WR_PNTR_WIDTH-C_RD_PNTR_WIDTH];
end
endgenerate
// Generate Empty and Almost Empty
// ram_rd_en used to determine EMPTY should depend on the EMPTY.
assign ram_rd_en = RD_EN & !EMPTY;
assign empty_int = ((adj_wr_pntr_rd == rd_pntr) || (ram_rd_en && (adj_wr_pntr_rd == (rd_pntr+1'h1))));
assign almost_empty_int = ((adj_wr_pntr_rd == (rd_pntr+1'h1)) || (ram_rd_en && (adj_wr_pntr_rd == (rd_pntr+2'h2))));
// Register Empty and Almost Empty
always @ (posedge RD_CLK or posedge rd_rst_i)
begin
if (rd_rst_i) begin
EMPTY <= #`TCQ 1'b1;
ALMOST_EMPTY <= #`TCQ 1'b1;
rd_data_count_int <= #`TCQ {C_RD_PNTR_WIDTH-1{1'b0}};
end else begin
rd_data_count_int <= #`TCQ {(adj_wr_pntr_rd[C_RD_PNTR_WIDTH-1:0] - rd_pntr[C_RD_PNTR_WIDTH-1:0]), 1'b0};
if (empty_int)
EMPTY <= #`TCQ 1'b1;
else
EMPTY <= #`TCQ 1'b0;
if (!EMPTY) begin
if (almost_empty_int)
ALMOST_EMPTY <= #`TCQ 1'b1;
else
ALMOST_EMPTY <= #`TCQ 1'b0;
end
end // rd_rst_i
end // always
// Read pointer adjustment based on pointers width for EMPTY/ALMOST_EMPTY generation
generate
if (C_WR_PNTR_WIDTH > C_RD_PNTR_WIDTH) begin : wdg // Write depth greater than read depth
assign adj_rd_pntr_wr[C_WR_PNTR_WIDTH-1:C_WR_PNTR_WIDTH-C_RD_PNTR_WIDTH] = rd_pntr_wr;
assign adj_rd_pntr_wr[C_WR_PNTR_WIDTH-C_RD_PNTR_WIDTH-1:0] = 0;
end else begin : wdl // Write depth lesser than or equal to read depth
assign adj_rd_pntr_wr = rd_pntr_wr[C_RD_PNTR_WIDTH-1:C_RD_PNTR_WIDTH-C_WR_PNTR_WIDTH];
end
endgenerate
// Generate FULL and ALMOST_FULL
// ram_wr_en used to determine FULL should depend on the FULL.
assign ram_wr_en = WR_EN & !FULL;
assign full_int = ((adj_rd_pntr_wr == (wr_pntr+1'h1)) || (ram_wr_en && (adj_rd_pntr_wr == (wr_pntr+2'h2))));
assign almost_full_int = ((adj_rd_pntr_wr == (wr_pntr+2'h2)) || (ram_wr_en && (adj_rd_pntr_wr == (wr_pntr+3'h3))));
// Register FULL and ALMOST_FULL Empty
always @ (posedge WR_CLK or posedge RST_FULL_FF)
begin
if (RST_FULL_FF) begin
FULL <= #`TCQ C_FULL_FLAGS_RST_VAL;
ALMOST_FULL <= #`TCQ C_FULL_FLAGS_RST_VAL;
wr_data_count_int <= #`TCQ {C_WR_DATA_COUNT_WIDTH-1{1'b0}};
end else begin
wr_data_count_int <= #`TCQ {(wr_pntr[C_WR_PNTR_WIDTH-1:0] - adj_rd_pntr_wr[C_WR_PNTR_WIDTH-1:0]), 1'b0};
if (full_int) begin
FULL <= #`TCQ 1'b1;
end else begin
FULL <= #`TCQ 1'b0;
end
if (RST_FULL_GEN) begin
ALMOST_FULL <= #`TCQ 1'b0;
end else if (!FULL) begin
if (almost_full_int)
ALMOST_FULL <= #`TCQ 1'b1;
else
ALMOST_FULL <= #`TCQ 1'b0;
end
end // wr_rst_i
end // always
// Determine which stage in FWFT registers are valid
reg stage1_valid = 0;
reg stage2_valid = 0;
generate
if (C_PRELOAD_LATENCY == 0) begin : grd_fwft_proc
always @ (posedge RD_CLK or posedge rd_rst_i) begin
if (rd_rst_i) begin
stage1_valid <= #`TCQ 0;
stage2_valid <= #`TCQ 0;
end else begin
if (!stage1_valid && !stage2_valid) begin
if (!EMPTY)
stage1_valid <= #`TCQ 1'b1;
else
stage1_valid <= #`TCQ 1'b0;
end else if (stage1_valid && !stage2_valid) begin
if (EMPTY) begin
stage1_valid <= #`TCQ 1'b0;
stage2_valid <= #`TCQ 1'b1;
end else begin
stage1_valid <= #`TCQ 1'b1;
stage2_valid <= #`TCQ 1'b1;
end
end else if (!stage1_valid && stage2_valid) begin
if (EMPTY && RD_EN_USER) begin
stage1_valid <= #`TCQ 1'b0;
stage2_valid <= #`TCQ 1'b0;
end else if (!EMPTY && RD_EN_USER) begin
stage1_valid <= #`TCQ 1'b1;
stage2_valid <= #`TCQ 1'b0;
end else if (!EMPTY && !RD_EN_USER) begin
stage1_valid <= #`TCQ 1'b1;
stage2_valid <= #`TCQ 1'b1;
end else begin
stage1_valid <= #`TCQ 1'b0;
stage2_valid <= #`TCQ 1'b1;
end
end else if (stage1_valid && stage2_valid) begin
if (EMPTY && RD_EN_USER) begin
stage1_valid <= #`TCQ 1'b0;
stage2_valid <= #`TCQ 1'b1;
end else begin
stage1_valid <= #`TCQ 1'b1;
stage2_valid <= #`TCQ 1'b1;
end
end else begin
stage1_valid <= #`TCQ 1'b0;
stage2_valid <= #`TCQ 1'b0;
end
end // rd_rst_i
end // always
end
endgenerate
//Pointers passed into opposite clock domain
reg [31:0] wr_ptr_rdclk;
reg [31:0] wr_ptr_rdclk_next;
reg [31:0] rd_ptr_wrclk;
reg [31:0] rd_ptr_wrclk_next;
//Amount of data stored in the FIFO scaled to the narrowest (deepest) port
// (Do not include data in FWFT stages)
//Used to calculate PROG_EMPTY.
wire [31:0] num_read_words_pe =
num_rd_bits/(C_DOUT_WIDTH/C_DEPTH_RATIO_WR);
//Amount of data stored in the FIFO scaled to the narrowest (deepest) port
// (Do not include data in FWFT stages)
//Used to calculate PROG_FULL.
wire [31:0] num_write_words_pf =
num_wr_bits/(C_DIN_WIDTH/C_DEPTH_RATIO_RD);
/**************************
* Read Data Count
*************************/
reg [31:0] num_read_words_dc;
reg [C_RD_DATA_COUNT_WIDTH-1:0] num_read_words_sized_i;
always @(num_rd_bits) begin
if (C_USE_FWFT_DATA_COUNT) begin
//If using extra logic for FWFT Data Counts,
// then scale FIFO contents to read domain,
// and add two read words for FWFT stages
//This value is only a temporary value and not used in the code.
num_read_words_dc = (num_rd_bits/C_DOUT_WIDTH+2);
//Trim the read words for use with RD_DATA_COUNT
num_read_words_sized_i =
num_read_words_dc[C_RD_PNTR_WIDTH : C_RD_PNTR_WIDTH-C_RD_DATA_COUNT_WIDTH+1];
end else begin
//If not using extra logic for FWFT Data Counts,
// then scale FIFO contents to read domain.
//This value is only a temporary value and not used in the code.
num_read_words_dc = num_rd_bits/C_DOUT_WIDTH;
//Trim the read words for use with RD_DATA_COUNT
num_read_words_sized_i =
num_read_words_dc[C_RD_PNTR_WIDTH-1 : C_RD_PNTR_WIDTH-C_RD_DATA_COUNT_WIDTH];
end //if (C_USE_FWFT_DATA_COUNT)
end //always
/**************************
* Write Data Count
*************************/
reg [31:0] num_write_words_dc;
reg [C_WR_DATA_COUNT_WIDTH-1:0] num_write_words_sized_i;
always @(num_wr_bits) begin
if (C_USE_FWFT_DATA_COUNT) begin
//Calculate the Data Count value for the number of write words,
// when using First-Word Fall-Through with extra logic for Data
// Counts. This takes into consideration the number of words that
// are expected to be stored in the FWFT register stages (it always
// assumes they are filled).
//This value is scaled to the Write Domain.
//The expression (((A-1)/B))+1 divides A/B, but takes the
// ceiling of the result.
//When num_wr_bits==0, set the result manually to prevent
// division errors.
//EXTRA_WORDS_DC is the number of words added to write_words
// due to FWFT.
//This value is only a temporary value and not used in the code.
num_write_words_dc = (num_wr_bits==0) ? EXTRA_WORDS_DC : (((num_wr_bits-1)/C_DIN_WIDTH)+1) + EXTRA_WORDS_DC ;
//Trim the write words for use with WR_DATA_COUNT
num_write_words_sized_i =
num_write_words_dc[C_WR_PNTR_WIDTH : C_WR_PNTR_WIDTH-C_WR_DATA_COUNT_WIDTH+1];
end else begin
//Calculate the Data Count value for the number of write words, when NOT
// using First-Word Fall-Through with extra logic for Data Counts. This
// calculates only the number of words in the internal FIFO.
//The expression (((A-1)/B))+1 divides A/B, but takes the
// ceiling of the result.
//This value is scaled to the Write Domain.
//When num_wr_bits==0, set the result manually to prevent
// division errors.
//This value is only a temporary value and not used in the code.
num_write_words_dc = (num_wr_bits==0) ? 0 : ((num_wr_bits-1)/C_DIN_WIDTH)+1;
//Trim the read words for use with RD_DATA_COUNT
num_write_words_sized_i =
num_write_words_dc[C_WR_PNTR_WIDTH-1 : C_WR_PNTR_WIDTH-C_WR_DATA_COUNT_WIDTH];
end //if (C_USE_FWFT_DATA_COUNT)
end //always
/***************************************************************************
* Internal registers and wires
**************************************************************************/
//Temporary signals used for calculating the model's outputs. These
//are only used in the assign statements immediately following wire,
//parameter, and function declarations.
wire [C_DOUT_WIDTH-1:0] ideal_dout_out;
wire valid_i;
wire valid_out;
wire underflow_i;
//Ideal FIFO signals. These are the raw output of the behavioral model,
//which behaves like an ideal FIFO.
reg [1:0] err_type = 0;
reg [1:0] err_type_d1 = 0;
reg [C_DOUT_WIDTH-1:0] ideal_dout = 0;
reg [C_DOUT_WIDTH-1:0] ideal_dout_d1 = 0;
reg ideal_wr_ack = 0;
reg ideal_valid = 0;
reg ideal_overflow = 0;
reg ideal_underflow = 0;
reg ideal_prog_full = 0;
reg ideal_prog_empty = 1;
reg [C_WR_DATA_COUNT_WIDTH-1 : 0] ideal_wr_count = 0;
reg [C_RD_DATA_COUNT_WIDTH-1 : 0] ideal_rd_count = 0;
//Assorted reg values for delayed versions of signals
reg valid_d1 = 0;
//user specified value for reseting the size of the fifo
reg [C_DOUT_WIDTH-1:0] dout_reset_val = 0;
//temporary registers for WR_RESPONSE_LATENCY feature
integer tmp_wr_listsize;
integer tmp_rd_listsize;
//Signal for registered version of prog full and empty
//Threshold values for Programmable Flags
integer prog_empty_actual_thresh_assert;
integer prog_empty_actual_thresh_negate;
integer prog_full_actual_thresh_assert;
integer prog_full_actual_thresh_negate;
/****************************************************************************
* Function Declarations
***************************************************************************/
/**************************************************************************
* write_fifo
* This task writes a word to the FIFO memory and updates the
* write pointer.
* FIFO size is relative to write domain.
***************************************************************************/
task write_fifo;
begin
memory[wr_ptr] <= DIN;
wr_pntr <= #`TCQ wr_pntr + 1;
// Store the type of error injection (double/single) on write
case (C_ERROR_INJECTION_TYPE)
3: ecc_err[wr_ptr] <= {INJECTDBITERR,INJECTSBITERR};
2: ecc_err[wr_ptr] <= {INJECTDBITERR,1'b0};
1: ecc_err[wr_ptr] <= {1'b0,INJECTSBITERR};
default: ecc_err[wr_ptr] <= 0;
endcase
// (Works opposite to core: wr_ptr is a DOWN counter)
if (wr_ptr == 0) begin
wr_ptr <= C_WR_DEPTH - 1;
end else begin
wr_ptr <= wr_ptr - 1;
end
end
endtask // write_fifo
/**************************************************************************
* read_fifo
* This task reads a word from the FIFO memory and updates the read
* pointer. It's output is the ideal_dout bus.
* FIFO size is relative to write domain.
***************************************************************************/
task read_fifo;
integer i;
reg [C_DOUT_WIDTH-1:0] tmp_dout;
reg [C_DIN_WIDTH-1:0] memory_read;
reg [31:0] tmp_rd_ptr;
reg [31:0] rd_ptr_high;
reg [31:0] rd_ptr_low;
reg [1:0] tmp_ecc_err;
begin
rd_pntr <= #`TCQ rd_pntr + 1;
// output is wider than input
if (reads_per_write == 0) begin
tmp_dout = 0;
tmp_rd_ptr = (rd_ptr << log2_writes_per_read)+(writes_per_read-1);
for (i = writes_per_read - 1; i >= 0; i = i - 1) begin
tmp_dout = tmp_dout << C_DIN_WIDTH;
tmp_dout = tmp_dout | memory[tmp_rd_ptr];
// (Works opposite to core: rd_ptr is a DOWN counter)
if (tmp_rd_ptr == 0) begin
tmp_rd_ptr = C_WR_DEPTH - 1;
end else begin
tmp_rd_ptr = tmp_rd_ptr - 1;
end
end
// output is symmetric
end else if (reads_per_write == 1) begin
tmp_dout = memory[rd_ptr][C_DIN_WIDTH-1:0];
// Retreive the error injection type. Based on the error injection type
// corrupt the output data.
tmp_ecc_err = ecc_err[rd_ptr];
if (ENABLE_ERR_INJECTION && C_DIN_WIDTH == C_DOUT_WIDTH) begin
if (tmp_ecc_err[1]) begin // Corrupt the output data only for double bit error
if (C_DOUT_WIDTH == 1)
tmp_dout = tmp_dout[C_DOUT_WIDTH-1:0];
else if (C_DOUT_WIDTH == 2)
tmp_dout = {~tmp_dout[C_DOUT_WIDTH-1],~tmp_dout[C_DOUT_WIDTH-2]};
else
tmp_dout = {~tmp_dout[C_DOUT_WIDTH-1],~tmp_dout[C_DOUT_WIDTH-2],(tmp_dout << 2)};
end else begin
tmp_dout = tmp_dout[C_DOUT_WIDTH-1:0];
end
err_type <= {tmp_ecc_err[1], tmp_ecc_err[0] & !tmp_ecc_err[1]};
end else begin
err_type <= 0;
end
// input is wider than output
end else begin
rd_ptr_high = rd_ptr >> log2_reads_per_write;
rd_ptr_low = rd_ptr & (reads_per_write - 1);
memory_read = memory[rd_ptr_high];
tmp_dout = memory_read >> (rd_ptr_low*C_DOUT_WIDTH);
end
ideal_dout <= tmp_dout;
// (Works opposite to core: rd_ptr is a DOWN counter)
if (rd_ptr == 0) begin
rd_ptr <= C_RD_DEPTH - 1;
end else begin
rd_ptr <= rd_ptr - 1;
end
end
endtask
/**************************************************************************
* log2_val
* Returns the 'log2' value for the input value for the supported ratios
***************************************************************************/
function [31:0] log2_val;
input [31:0] binary_val;
begin
if (binary_val == 8) begin
log2_val = 3;
end else if (binary_val == 4) begin
log2_val = 2;
end else begin
log2_val = 1;
end
end
endfunction
/***********************************************************************
* hexstr_conv
* Converts a string of type hex to a binary value (for C_DOUT_RST_VAL)
***********************************************************************/
function [C_DOUT_WIDTH-1:0] hexstr_conv;
input [(C_DOUT_WIDTH*8)-1:0] def_data;
integer index,i,j;
reg [3:0] bin;
begin
index = 0;
hexstr_conv = 'b0;
for( i=C_DOUT_WIDTH-1; i>=0; i=i-1 )
begin
case (def_data[7:0])
8'b00000000 :
begin
bin = 4'b0000;
i = -1;
end
8'b00110000 : bin = 4'b0000;
8'b00110001 : bin = 4'b0001;
8'b00110010 : bin = 4'b0010;
8'b00110011 : bin = 4'b0011;
8'b00110100 : bin = 4'b0100;
8'b00110101 : bin = 4'b0101;
8'b00110110 : bin = 4'b0110;
8'b00110111 : bin = 4'b0111;
8'b00111000 : bin = 4'b1000;
8'b00111001 : bin = 4'b1001;
8'b01000001 : bin = 4'b1010;
8'b01000010 : bin = 4'b1011;
8'b01000011 : bin = 4'b1100;
8'b01000100 : bin = 4'b1101;
8'b01000101 : bin = 4'b1110;
8'b01000110 : bin = 4'b1111;
8'b01100001 : bin = 4'b1010;
8'b01100010 : bin = 4'b1011;
8'b01100011 : bin = 4'b1100;
8'b01100100 : bin = 4'b1101;
8'b01100101 : bin = 4'b1110;
8'b01100110 : bin = 4'b1111;
default :
begin
bin = 4'bx;
end
endcase
for( j=0; j<4; j=j+1)
begin
if ((index*4)+j < C_DOUT_WIDTH)
begin
hexstr_conv[(index*4)+j] = bin[j];
end
end
index = index + 1;
def_data = def_data >> 8;
end
end
endfunction
/*************************************************************************
* Initialize Signals for clean power-on simulation
*************************************************************************/
initial begin
num_wr_bits = 0;
num_rd_bits = 0;
next_num_wr_bits = 0;
next_num_rd_bits = 0;
rd_ptr = C_RD_DEPTH - 1;
wr_ptr = C_WR_DEPTH - 1;
wr_pntr = 0;
rd_pntr = 0;
rd_ptr_wrclk = rd_ptr;
wr_ptr_rdclk = wr_ptr;
dout_reset_val = hexstr_conv(C_DOUT_RST_VAL);
ideal_dout = dout_reset_val;
err_type = 0;
ideal_dout_d1 = dout_reset_val;
ideal_wr_ack = 1'b0;
ideal_valid = 1'b0;
valid_d1 = 1'b0;
ideal_overflow = 1'b0;
ideal_underflow = 1'b0;
ideal_wr_count = 0;
ideal_rd_count = 0;
ideal_prog_full = 1'b0;
ideal_prog_empty = 1'b1;
end
/*************************************************************************
* Connect the module inputs and outputs to the internal signals of the
* behavioral model.
*************************************************************************/
//Inputs
/*
wire [C_DIN_WIDTH-1:0] DIN;
wire [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH;
wire [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_ASSERT;
wire [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_NEGATE;
wire [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH;
wire [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_ASSERT;
wire [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_NEGATE;
wire RD_CLK;
wire RD_EN;
wire RST;
wire WR_CLK;
wire WR_EN;
*/
//***************************************************************************
// Dout may change behavior based on latency
//***************************************************************************
assign ideal_dout_out[C_DOUT_WIDTH-1:0] = (C_PRELOAD_LATENCY==2 &&
(C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1))?
ideal_dout_d1: ideal_dout;
assign DOUT[C_DOUT_WIDTH-1:0] = ideal_dout_out;
//***************************************************************************
// Assign SBITERR and DBITERR based on latency
//***************************************************************************
assign SBITERR = (C_ERROR_INJECTION_TYPE == 1 || C_ERROR_INJECTION_TYPE == 3) &&
(C_PRELOAD_LATENCY == 2 &&
(C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1)) ?
err_type_d1[0]: err_type[0];
assign DBITERR = (C_ERROR_INJECTION_TYPE == 2 || C_ERROR_INJECTION_TYPE == 3) &&
(C_PRELOAD_LATENCY==2 && (C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1)) ?
err_type_d1[1]: err_type[1];
//***************************************************************************
// Overflow may be active-low
//***************************************************************************
generate
if (C_HAS_OVERFLOW==1) begin : blockOF1
assign OVERFLOW = ideal_overflow ? !C_OVERFLOW_LOW : C_OVERFLOW_LOW;
end
endgenerate
assign PROG_EMPTY = ideal_prog_empty;
assign PROG_FULL = ideal_prog_full;
//***************************************************************************
// Valid may change behavior based on latency or active-low
//***************************************************************************
generate
if (C_HAS_VALID==1) begin : blockVL1
assign valid_i = (C_PRELOAD_LATENCY==0) ? (RD_EN & ~EMPTY) : ideal_valid;
assign valid_out = (C_PRELOAD_LATENCY==2 &&
(C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1))?
valid_d1: valid_i;
assign VALID = valid_out ? !C_VALID_LOW : C_VALID_LOW;
end
endgenerate
//***************************************************************************
// Underflow may change behavior based on latency or active-low
//***************************************************************************
generate
if (C_HAS_UNDERFLOW==1) begin : blockUF1
assign underflow_i = (C_PRELOAD_LATENCY==0) ? (RD_EN & EMPTY) : ideal_underflow;
assign UNDERFLOW = underflow_i ? !C_UNDERFLOW_LOW : C_UNDERFLOW_LOW;
end
endgenerate
//***************************************************************************
// Write acknowledge may be active low
//***************************************************************************
generate
if (C_HAS_WR_ACK==1) begin : blockWK1
assign WR_ACK = ideal_wr_ack ? !C_WR_ACK_LOW : C_WR_ACK_LOW;
end
endgenerate
//***************************************************************************
// Generate RD_DATA_COUNT if Use Extra Logic option is selected
//***************************************************************************
generate
if (C_HAS_WR_DATA_COUNT == 1 && C_USE_FWFT_DATA_COUNT == 1) begin : wdc_fwft_ext
reg [C_PNTR_WIDTH-1:0] adjusted_wr_pntr = 0;
reg [C_PNTR_WIDTH-1:0] adjusted_rd_pntr = 0;
wire [C_PNTR_WIDTH-1:0] diff_wr_rd_tmp;
wire [C_PNTR_WIDTH:0] diff_wr_rd;
reg [C_PNTR_WIDTH:0] wr_data_count_i = 0;
always @* begin
if (C_WR_PNTR_WIDTH > C_RD_PNTR_WIDTH) begin
adjusted_wr_pntr = wr_pntr;
adjusted_rd_pntr = 0;
adjusted_rd_pntr[C_PNTR_WIDTH-1:C_PNTR_WIDTH-C_RD_PNTR_WIDTH] = rd_pntr_wr;
end else if (C_WR_PNTR_WIDTH < C_RD_PNTR_WIDTH) begin
adjusted_rd_pntr = rd_pntr_wr;
adjusted_wr_pntr = 0;
adjusted_wr_pntr[C_PNTR_WIDTH-1:C_PNTR_WIDTH-C_WR_PNTR_WIDTH] = wr_pntr;
end else begin
adjusted_wr_pntr = wr_pntr;
adjusted_rd_pntr = rd_pntr_wr;
end
end // always @*
assign diff_wr_rd_tmp = adjusted_wr_pntr - adjusted_rd_pntr;
assign diff_wr_rd = {1'b0,diff_wr_rd_tmp};
always @ (posedge wr_rst_i or posedge WR_CLK)
begin
if (wr_rst_i)
wr_data_count_i <= #`TCQ 0;
else
wr_data_count_i <= #`TCQ diff_wr_rd + EXTRA_WORDS_DC;
end // always @ (posedge WR_CLK or posedge WR_CLK)
always @* begin
if (C_WR_PNTR_WIDTH >= C_RD_PNTR_WIDTH)
wdc_fwft_ext_as = wr_data_count_i[C_PNTR_WIDTH:0];
else
wdc_fwft_ext_as = wr_data_count_i[C_PNTR_WIDTH:C_RD_PNTR_WIDTH-C_WR_PNTR_WIDTH];
end // always @*
end // wdc_fwft_ext
endgenerate
//***************************************************************************
// Generate RD_DATA_COUNT if Use Extra Logic option is selected
//***************************************************************************
reg [C_RD_PNTR_WIDTH:0] rdc_fwft_ext_as = 0;
generate
if (C_HAS_RD_DATA_COUNT == 1 && C_USE_FWFT_DATA_COUNT == 1) begin : rdc_fwft_ext
reg [C_RD_PNTR_WIDTH-1:0] adjusted_wr_pntr_rd = 0;
wire [C_RD_PNTR_WIDTH-1:0] diff_rd_wr_tmp;
wire [C_RD_PNTR_WIDTH:0] diff_rd_wr;
always @* begin
if (C_RD_PNTR_WIDTH > C_WR_PNTR_WIDTH) begin
adjusted_wr_pntr_rd = 0;
adjusted_wr_pntr_rd[C_RD_PNTR_WIDTH-1:C_RD_PNTR_WIDTH-C_WR_PNTR_WIDTH] = wr_pntr_rd;
end else begin
adjusted_wr_pntr_rd = wr_pntr_rd[C_WR_PNTR_WIDTH-1:C_WR_PNTR_WIDTH-C_RD_PNTR_WIDTH];
end
end // always @*
assign diff_rd_wr_tmp = adjusted_wr_pntr_rd - rd_pntr;
assign diff_rd_wr = {1'b0,diff_rd_wr_tmp};
always @ (posedge rd_rst_i or posedge RD_CLK)
begin
if (rd_rst_i) begin
rdc_fwft_ext_as <= #`TCQ 0;
end else begin
if (!stage2_valid)
rdc_fwft_ext_as <= #`TCQ 0;
else if (!stage1_valid && stage2_valid)
rdc_fwft_ext_as <= #`TCQ 1;
else
rdc_fwft_ext_as <= #`TCQ diff_rd_wr + 2'h2;
end
end // always @ (posedge WR_CLK or posedge WR_CLK)
end // rdc_fwft_ext
endgenerate
//***************************************************************************
// Assign the read data count value only if it is selected,
// otherwise output zeros.
//***************************************************************************
generate
if (C_HAS_RD_DATA_COUNT == 1) begin : grdc
assign RD_DATA_COUNT[C_RD_DATA_COUNT_WIDTH-1:0] = C_USE_FWFT_DATA_COUNT ?
rdc_fwft_ext_as[C_RD_PNTR_WIDTH:C_RD_PNTR_WIDTH+1-C_RD_DATA_COUNT_WIDTH] :
rd_data_count_int[C_RD_PNTR_WIDTH:C_RD_PNTR_WIDTH+1-C_RD_DATA_COUNT_WIDTH];
end
endgenerate
generate
if (C_HAS_RD_DATA_COUNT == 0) begin : gnrdc
assign RD_DATA_COUNT[C_RD_DATA_COUNT_WIDTH-1:0] = {C_RD_DATA_COUNT_WIDTH-1{1'b0}};
end
endgenerate
//***************************************************************************
// Assign the write data count value only if it is selected,
// otherwise output zeros
//***************************************************************************
generate
if (C_HAS_WR_DATA_COUNT == 1) begin : gwdc
assign WR_DATA_COUNT[C_WR_DATA_COUNT_WIDTH-1:0] = (C_USE_FWFT_DATA_COUNT == 1) ?
wdc_fwft_ext_as[C_WR_PNTR_WIDTH:C_WR_PNTR_WIDTH+1-C_WR_DATA_COUNT_WIDTH] :
wr_data_count_int[C_WR_PNTR_WIDTH:C_WR_PNTR_WIDTH+1-C_WR_DATA_COUNT_WIDTH];
end
endgenerate
generate
if (C_HAS_WR_DATA_COUNT == 0) begin : gnwdc
assign WR_DATA_COUNT[C_WR_DATA_COUNT_WIDTH-1:0] = {C_WR_DATA_COUNT_WIDTH-1{1'b0}};
end
endgenerate
/**************************************************************************
* Assorted registers for delayed versions of signals
**************************************************************************/
//Capture delayed version of valid
generate
if (C_HAS_VALID==1) begin : blockVL2
always @(posedge RD_CLK or posedge rd_rst_i) begin
if (rd_rst_i == 1'b1) begin
valid_d1 <= #`TCQ 1'b0;
end else begin
valid_d1 <= #`TCQ valid_i;
end
end
end
endgenerate
//Capture delayed version of dout
always @(posedge RD_CLK or posedge rd_rst_i) begin
if (rd_rst_i == 1'b1) begin
// Reset err_type only if ECC is not selected
if (C_USE_ECC == 0)
err_type_d1 <= #`TCQ 0;
end else if (ram_rd_en_d1) begin
ideal_dout_d1 <= #`TCQ ideal_dout;
err_type_d1 <= #`TCQ err_type;
end
end
/**************************************************************************
* Overflow and Underflow Flag calculation
* (handled separately because they don't support rst)
**************************************************************************/
generate
if (C_HAS_OVERFLOW==1) begin : blockOF2
always @(posedge WR_CLK) begin
ideal_overflow <= #`TCQ WR_EN & FULL;
end
end
endgenerate
generate
if (C_HAS_UNDERFLOW==1) begin : blockUF2
always @(posedge RD_CLK) begin
ideal_underflow <= #`TCQ EMPTY & RD_EN;
end
end
endgenerate
/**************************************************************************
* Write Domain Logic
**************************************************************************/
reg [C_WR_PNTR_WIDTH-1:0] diff_pntr = 0;
always @(posedge WR_CLK or posedge wr_rst_i) begin : gen_fifo_w
/****** Reset fifo (case 1)***************************************/
if (wr_rst_i == 1'b1) begin
num_wr_bits <= #`TCQ 0;
next_num_wr_bits = #`TCQ 0;
wr_ptr <= #`TCQ C_WR_DEPTH - 1;
rd_ptr_wrclk <= #`TCQ C_RD_DEPTH - 1;
ideal_wr_ack <= #`TCQ 0;
ideal_wr_count <= #`TCQ 0;
tmp_wr_listsize = #`TCQ 0;
rd_ptr_wrclk_next <= #`TCQ 0;
wr_pntr <= #`TCQ 0;
wr_pntr_rd1 <= #`TCQ 0;
rd_pntr_wr2 <= #`TCQ 0;
rd_pntr_wr3 <= #`TCQ 0;
rd_pntr_wr4 <= #`TCQ 0;
rd_pntr_wr <= #`TCQ 0;
end else begin //wr_rst_i==0
wr_pntr_rd1 <= #`TCQ wr_pntr;
// Synchronize the rd_pntr in read domain
rd_pntr_wr2 <= #`TCQ rd_pntr_wr1;
rd_pntr_wr3 <= #`TCQ rd_pntr_wr2;
rd_pntr_wr4 <= #`TCQ rd_pntr_wr2;
rd_pntr_wr <= #`TCQ rd_pntr_wr4;
//Determine the current number of words in the FIFO
tmp_wr_listsize = (C_DEPTH_RATIO_RD > 1) ? num_wr_bits/C_DOUT_WIDTH :
num_wr_bits/C_DIN_WIDTH;
rd_ptr_wrclk_next = rd_ptr;
if (rd_ptr_wrclk < rd_ptr_wrclk_next) begin
next_num_wr_bits = num_wr_bits -
C_DOUT_WIDTH*(rd_ptr_wrclk + C_RD_DEPTH
- rd_ptr_wrclk_next);
end else begin
next_num_wr_bits = num_wr_bits -
C_DOUT_WIDTH*(rd_ptr_wrclk - rd_ptr_wrclk_next);
end
//If this is a write, handle the write by adding the value
// to the linked list, and updating all outputs appropriately
if (WR_EN == 1'b1) begin
if (FULL == 1'b1) begin
//If the FIFO is full, do NOT perform the write,
// update flags accordingly
if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD
>= C_FIFO_WR_DEPTH) begin
//write unsuccessful - do not change contents
//Do not acknowledge the write
ideal_wr_ack <= #`TCQ 0;
//Reminder that FIFO is still full
ideal_wr_count <= #`TCQ num_write_words_sized_i;
//If the FIFO is one from full, but reporting full
end else
if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD ==
C_FIFO_WR_DEPTH-1) begin
//No change to FIFO
//Write not successful
ideal_wr_ack <= #`TCQ 0;
//With DEPTH-1 words in the FIFO, it is almost_full
ideal_wr_count <= #`TCQ num_write_words_sized_i;
//If the FIFO is completely empty, but it is
// reporting FULL for some reason (like reset)
end else
if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD <=
C_FIFO_WR_DEPTH-2) begin
//No change to FIFO
//Write not successful
ideal_wr_ack <= #`TCQ 0;
//FIFO is really not close to full, so change flag status.
ideal_wr_count <= #`TCQ num_write_words_sized_i;
end //(tmp_wr_listsize == 0)
end else begin
//If the FIFO is full, do NOT perform the write,
// update flags accordingly
if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD >=
C_FIFO_WR_DEPTH) begin
//write unsuccessful - do not change contents
//Do not acknowledge the write
ideal_wr_ack <= #`TCQ 0;
//Reminder that FIFO is still full
ideal_wr_count <= #`TCQ num_write_words_sized_i;
//If the FIFO is one from full
end else
if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD ==
C_FIFO_WR_DEPTH-1) begin
//Add value on DIN port to FIFO
write_fifo;
next_num_wr_bits = next_num_wr_bits + C_DIN_WIDTH;
//Write successful, so issue acknowledge
// and no error
ideal_wr_ack <= #`TCQ 1;
//This write is CAUSING the FIFO to go full
ideal_wr_count <= #`TCQ num_write_words_sized_i;
//If the FIFO is 2 from full
end else
if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD ==
C_FIFO_WR_DEPTH-2) begin
//Add value on DIN port to FIFO
write_fifo;
next_num_wr_bits = next_num_wr_bits + C_DIN_WIDTH;
//Write successful, so issue acknowledge
// and no error
ideal_wr_ack <= #`TCQ 1;
//Still 2 from full
ideal_wr_count <= #`TCQ num_write_words_sized_i;
//If the FIFO is not close to being full
end else
if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD <
C_FIFO_WR_DEPTH-2) begin
//Add value on DIN port to FIFO
write_fifo;
next_num_wr_bits = next_num_wr_bits + C_DIN_WIDTH;
//Write successful, so issue acknowledge
// and no error
ideal_wr_ack <= #`TCQ 1;
//Not even close to full.
ideal_wr_count <= num_write_words_sized_i;
end
end
end else begin //(WR_EN == 1'b1)
//If user did not attempt a write, then do not
// give ack or err
ideal_wr_ack <= #`TCQ 0;
ideal_wr_count <= #`TCQ num_write_words_sized_i;
end
num_wr_bits <= #`TCQ next_num_wr_bits;
rd_ptr_wrclk <= #`TCQ rd_ptr;
end //wr_rst_i==0
end // write always
/***************************************************************************
* Programmable FULL flags
***************************************************************************/
always @(posedge WR_CLK or posedge RST_FULL_FF) begin : gen_pf
if (RST_FULL_FF == 1'b1) begin
diff_pntr <= 0;
ideal_prog_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
end else begin
if (ram_wr_en)
diff_pntr <= #`TCQ (wr_pntr - adj_rd_pntr_wr + 2'h1);
else if (!ram_wr_en)
diff_pntr <= #`TCQ (wr_pntr - adj_rd_pntr_wr);
if (RST_FULL_GEN)
ideal_prog_full <= #`TCQ 0;
//Single Programmable Full Constant Threshold
else if (C_PROG_FULL_TYPE == 1) begin
if (FULL == 0) begin
if (diff_pntr >= C_PROG_FULL_THRESH_ASSERT_VAL)
ideal_prog_full <= #`TCQ 1;
else
ideal_prog_full <= #`TCQ 0;
end else
ideal_prog_full <= #`TCQ ideal_prog_full;
//Two Programmable Full Constant Thresholds
end else if (C_PROG_FULL_TYPE == 2) begin
if (FULL == 0) begin
if (diff_pntr >= C_PROG_FULL_THRESH_ASSERT_VAL)
ideal_prog_full <= #`TCQ 1;
else if (diff_pntr < C_PROG_FULL_THRESH_NEGATE_VAL)
ideal_prog_full <= #`TCQ 0;
else
ideal_prog_full <= #`TCQ ideal_prog_full;
end else
ideal_prog_full <= #`TCQ ideal_prog_full;
//Single Programmable Full Threshold Input
end else if (C_PROG_FULL_TYPE == 3) begin
if (FULL == 0) begin
if (diff_pntr >= PROG_FULL_THRESH)
ideal_prog_full <= #`TCQ 1;
else
ideal_prog_full <= #`TCQ 0;
end else
ideal_prog_full <= #`TCQ ideal_prog_full;
//Two Programmable Full Threshold Inputs
end else if (C_PROG_FULL_TYPE == 4) begin
if (FULL == 0) begin
if (diff_pntr >= PROG_FULL_THRESH_ASSERT)
ideal_prog_full <= #`TCQ 1;
else if (diff_pntr < PROG_FULL_THRESH_NEGATE)
ideal_prog_full <= #`TCQ 0;
else
ideal_prog_full <= #`TCQ ideal_prog_full;
end else
ideal_prog_full <= #`TCQ ideal_prog_full;
end // C_PROG_FULL_TYPE
end //wr_rst_i==0
end //
/**************************************************************************
* Read Domain Logic
**************************************************************************/
/*********************************************************
* Programmable EMPTY flags
*********************************************************/
//Determine the Assert and Negate thresholds for Programmable Empty
reg [C_RD_PNTR_WIDTH-1:0] pe_thr_assert_val = 0;
reg [C_RD_PNTR_WIDTH-1:0] pe_thr_negate_val = 0;
reg [C_RD_PNTR_WIDTH-1:0] diff_pntr_rd = 0;
always @* begin
if (C_PROG_EMPTY_TYPE == 3) begin
// If empty input threshold is selected, then subtract 2 for FWFT to
// compensate the FWFT stage, otherwise assign the input value.
if (C_PRELOAD_REGS == 1 && C_PRELOAD_LATENCY == 0) // FWFT
pe_thr_assert_val <= PROG_EMPTY_THRESH - 2'h2;
else
pe_thr_assert_val <= PROG_EMPTY_THRESH;
end else if (C_PROG_EMPTY_TYPE == 4) begin
// If empty input threshold is selected, then subtract 2 for FWFT to
// compensate the FWFT stage, otherwise assign the input value.
if (C_PRELOAD_REGS == 1 && C_PRELOAD_LATENCY == 0) begin // FWFT
pe_thr_assert_val <= PROG_EMPTY_THRESH_ASSERT - 2'h2;
pe_thr_negate_val <= PROG_EMPTY_THRESH_NEGATE - 2'h2;
end else begin
pe_thr_assert_val <= PROG_EMPTY_THRESH_ASSERT;
pe_thr_negate_val <= PROG_EMPTY_THRESH_NEGATE;
end
end else begin
if (C_PRELOAD_REGS == 1 && C_PRELOAD_LATENCY == 0) begin // FWFT
pe_thr_assert_val <= C_PROG_EMPTY_THRESH_ASSERT_VAL - 2;
pe_thr_negate_val <= C_PROG_EMPTY_THRESH_NEGATE_VAL - 2;
end else begin
pe_thr_assert_val <= C_PROG_EMPTY_THRESH_ASSERT_VAL;
pe_thr_negate_val <= C_PROG_EMPTY_THRESH_NEGATE_VAL;
end
end
end // always @*
always @(posedge RD_CLK or posedge rd_rst_i) begin : gen_pe
if (rd_rst_i) begin
diff_pntr_rd <= #`TCQ 0;
ideal_prog_empty <= #`TCQ 1'b1;
end else begin
if (ram_rd_en)
diff_pntr_rd <= #`TCQ (adj_wr_pntr_rd - rd_pntr) - 1'h1;
else if (!ram_rd_en)
diff_pntr_rd <= #`TCQ (adj_wr_pntr_rd - rd_pntr);
else
diff_pntr_rd <= #`TCQ diff_pntr_rd;
if (C_PROG_EMPTY_TYPE == 1) begin
if (EMPTY == 0) begin
if (diff_pntr_rd <= pe_thr_assert_val)
ideal_prog_empty <= #`TCQ 1;
else
ideal_prog_empty <= #`TCQ 0;
end else
ideal_prog_empty <= #`TCQ ideal_prog_empty;
end else if (C_PROG_EMPTY_TYPE == 2) begin
if (EMPTY == 0) begin
if (diff_pntr_rd <= pe_thr_assert_val)
ideal_prog_empty <= #`TCQ 1;
else if (diff_pntr_rd > pe_thr_negate_val)
ideal_prog_empty <= #`TCQ 0;
else
ideal_prog_empty <= #`TCQ ideal_prog_empty;
end else
ideal_prog_empty <= #`TCQ ideal_prog_empty;
end else if (C_PROG_EMPTY_TYPE == 3) begin
if (EMPTY == 0) begin
if (diff_pntr_rd <= pe_thr_assert_val)
ideal_prog_empty <= #`TCQ 1;
else
ideal_prog_empty <= #`TCQ 0;
end else
ideal_prog_empty <= #`TCQ ideal_prog_empty;
end else if (C_PROG_EMPTY_TYPE == 4) begin
if (EMPTY == 0) begin
if (diff_pntr_rd >= pe_thr_assert_val)
ideal_prog_empty <= #`TCQ 1;
else if (diff_pntr_rd > pe_thr_negate_val)
ideal_prog_empty <= #`TCQ 0;
else
ideal_prog_empty <= #`TCQ ideal_prog_empty;
end else
ideal_prog_empty <= #`TCQ ideal_prog_empty;
end //C_PROG_EMPTY_TYPE
end
end
// block memory has a synchronous reset
always @(posedge RD_CLK) begin : gen_fifo_blkmemdout
// make it consistent with the core.
if (rd_rst_i) begin
// Reset err_type only if ECC is not selected
if (C_USE_ECC == 0 && C_MEMORY_TYPE < 2)
err_type <= #`TCQ 0;
// BRAM resets synchronously
if (C_USE_DOUT_RST == 1 && C_MEMORY_TYPE < 2) begin
ideal_dout <= #`TCQ dout_reset_val;
ideal_dout_d1 <= #`TCQ dout_reset_val;
end
end
end //always
always @(posedge RD_CLK or posedge rd_rst_i) begin : gen_fifo_r
/****** Reset fifo (case 1)***************************************/
if (rd_rst_i) begin
num_rd_bits <= #`TCQ 0;
next_num_rd_bits = #`TCQ 0;
rd_ptr <= #`TCQ C_RD_DEPTH -1;
rd_pntr <= #`TCQ 0;
rd_pntr_wr1 <= #`TCQ 0;
wr_pntr_rd2 <= #`TCQ 0;
wr_pntr_rd3 <= #`TCQ 0;
wr_pntr_rd <= #`TCQ 0;
wr_ptr_rdclk <= #`TCQ C_WR_DEPTH -1;
// DRAM resets asynchronously
if (C_MEMORY_TYPE == 2 && C_USE_DOUT_RST == 1)
ideal_dout <= #`TCQ dout_reset_val;
// Reset err_type only if ECC is not selected
if (C_USE_ECC == 0)
err_type <= #`TCQ 0;
ideal_valid <= #`TCQ 1'b0;
ideal_rd_count <= #`TCQ 0;
end else begin //rd_rst_i==0
rd_pntr_wr1 <= #`TCQ rd_pntr;
// Synchronize the wr_pntr in read domain
wr_pntr_rd2 <= #`TCQ wr_pntr_rd1;
wr_pntr_rd3 <= #`TCQ wr_pntr_rd2;
wr_pntr_rd <= #`TCQ wr_pntr_rd3;
//Determine the current number of words in the FIFO
tmp_rd_listsize = (C_DEPTH_RATIO_WR > 1) ? num_rd_bits/C_DIN_WIDTH :
num_rd_bits/C_DOUT_WIDTH;
wr_ptr_rdclk_next = wr_ptr;
if (wr_ptr_rdclk < wr_ptr_rdclk_next) begin
next_num_rd_bits = num_rd_bits +
C_DIN_WIDTH*(wr_ptr_rdclk +C_WR_DEPTH
- wr_ptr_rdclk_next);
end else begin
next_num_rd_bits = num_rd_bits +
C_DIN_WIDTH*(wr_ptr_rdclk - wr_ptr_rdclk_next);
end
/*****************************************************************/
// Read Operation - Read Latency 1
/*****************************************************************/
if (C_PRELOAD_LATENCY==1 || C_PRELOAD_LATENCY==2) begin
ideal_valid <= #`TCQ 1'b0;
if (ram_rd_en == 1'b1) begin
if (EMPTY == 1'b1) begin
//If the FIFO is completely empty, and is reporting empty
if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0)
begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
//Reminder that FIFO is still empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if (tmp_rd_listsize <= 0)
//If the FIFO is one from empty, but it is reporting empty
else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 1)
begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
//Note that FIFO is no longer empty, but is almost empty (has one word left)
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if (tmp_rd_listsize == 1)
//If the FIFO is two from empty, and is reporting empty
else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 2)
begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
//Fifo has two words, so is neither empty or almost empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if (tmp_rd_listsize == 2)
//If the FIFO is not close to empty, but is reporting that it is
// Treat the FIFO as empty this time, but unset EMPTY flags.
if ((tmp_rd_listsize/C_DEPTH_RATIO_WR > 2) && (tmp_rd_listsize/C_DEPTH_RATIO_WR<C_FIFO_RD_DEPTH))
begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
//Note that the FIFO is No Longer Empty or Almost Empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if ((tmp_rd_listsize > 2) && (tmp_rd_listsize<=C_FIFO_RD_DEPTH-1))
end // else: if(ideal_empty == 1'b1)
else //if (ideal_empty == 1'b0)
begin
//If the FIFO is completely full, and we are successfully reading from it
if (tmp_rd_listsize/C_DEPTH_RATIO_WR >= C_FIFO_RD_DEPTH)
begin
//Read the value from the FIFO
read_fifo;
next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH;
//Acknowledge the read from the FIFO, no error
ideal_valid <= #`TCQ 1'b1;
//Not close to empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if (tmp_rd_listsize == C_FIFO_RD_DEPTH)
//If the FIFO is not close to being empty
else if ((tmp_rd_listsize/C_DEPTH_RATIO_WR > 2) && (tmp_rd_listsize/C_DEPTH_RATIO_WR<=C_FIFO_RD_DEPTH))
begin
//Read the value from the FIFO
read_fifo;
next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH;
//Acknowledge the read from the FIFO, no error
ideal_valid <= #`TCQ 1'b1;
//Not close to empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if ((tmp_rd_listsize > 2) && (tmp_rd_listsize<=C_FIFO_RD_DEPTH-1))
//If the FIFO is two from empty
else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 2)
begin
//Read the value from the FIFO
read_fifo;
next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH;
//Acknowledge the read from the FIFO, no error
ideal_valid <= #`TCQ 1'b1;
//Fifo is not yet empty. It is going almost_empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if (tmp_rd_listsize == 2)
//If the FIFO is one from empty
else if ((tmp_rd_listsize/C_DEPTH_RATIO_WR == 1))
begin
//Read the value from the FIFO
read_fifo;
next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH;
//Acknowledge the read from the FIFO, no error
ideal_valid <= #`TCQ 1'b1;
//Note that FIFO is GOING empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if (tmp_rd_listsize == 1)
//If the FIFO is completely empty
else if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0)
begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if (tmp_rd_listsize <= 0)
end // if (ideal_empty == 1'b0)
end //(RD_EN == 1'b1)
else //if (RD_EN == 1'b0)
begin
//If user did not attempt a read, do not give an ack or err
ideal_valid <= #`TCQ 1'b0;
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // else: !if(RD_EN == 1'b1)
/*****************************************************************/
// Read Operation - Read Latency 0
/*****************************************************************/
end else if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin
ideal_valid <= #`TCQ 1'b0;
if (ram_rd_en == 1'b1) begin
if (EMPTY == 1'b1) begin
//If the FIFO is completely empty, and is reporting empty
if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0) begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
//Reminder that FIFO is still empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
//If the FIFO is one from empty, but it is reporting empty
end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 1) begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
//Note that FIFO is no longer empty, but is almost empty (has one word left)
ideal_rd_count <= #`TCQ num_read_words_sized_i;
//If the FIFO is two from empty, and is reporting empty
end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 2) begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
//Fifo has two words, so is neither empty or almost empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
//If the FIFO is not close to empty, but is reporting that it is
// Treat the FIFO as empty this time, but unset EMPTY flags.
end else if ((tmp_rd_listsize/C_DEPTH_RATIO_WR > 2) &&
(tmp_rd_listsize/C_DEPTH_RATIO_WR<C_FIFO_RD_DEPTH)) begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
//Note that the FIFO is No Longer Empty or Almost Empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if ((tmp_rd_listsize > 2) && (tmp_rd_listsize<=C_FIFO_RD_DEPTH-1))
end else begin
//If the FIFO is completely full, and we are successfully reading from it
if (tmp_rd_listsize/C_DEPTH_RATIO_WR >= C_FIFO_RD_DEPTH) begin
//Read the value from the FIFO
read_fifo;
next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH;
//Acknowledge the read from the FIFO, no error
ideal_valid <= #`TCQ 1'b1;
//Not close to empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
//If the FIFO is not close to being empty
end else if ((tmp_rd_listsize/C_DEPTH_RATIO_WR > 2) &&
(tmp_rd_listsize/C_DEPTH_RATIO_WR<=C_FIFO_RD_DEPTH)) begin
//Read the value from the FIFO
read_fifo;
next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH;
//Acknowledge the read from the FIFO, no error
ideal_valid <= #`TCQ 1'b1;
//Not close to empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
//If the FIFO is two from empty
end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 2) begin
//Read the value from the FIFO
read_fifo;
next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH;
//Acknowledge the read from the FIFO, no error
ideal_valid <= #`TCQ 1'b1;
//Fifo is not yet empty. It is going almost_empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
//If the FIFO is one from empty
end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 1) begin
//Read the value from the FIFO
read_fifo;
next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH;
//Acknowledge the read from the FIFO, no error
ideal_valid <= #`TCQ 1'b1;
//Note that FIFO is GOING empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
//If the FIFO is completely empty
end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0) begin
//Do not change the contents of the FIFO
//Do not acknowledge the read from empty FIFO
ideal_valid <= #`TCQ 1'b0;
//Reminder that FIFO is still empty
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // if (tmp_rd_listsize <= 0)
end // if (ideal_empty == 1'b0)
end else begin//(RD_EN == 1'b0)
//If user did not attempt a read, do not give an ack or err
ideal_valid <= #`TCQ 1'b0;
ideal_rd_count <= #`TCQ num_read_words_sized_i;
end // else: !if(RD_EN == 1'b1)
end //if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0)
num_rd_bits <= #`TCQ next_num_rd_bits;
wr_ptr_rdclk <= #`TCQ wr_ptr;
end //rd_rst_i==0
end //always
endmodule // fifo_generator_v6_1_bhv_ver_as
/*******************************************************************************
* Declaration of top-level module
******************************************************************************/
module fifo_generator_v6_1_bhv_ver_ss
/**************************************************************************
* Declare user parameters and their defaults
*************************************************************************/
#(
parameter C_DATA_COUNT_WIDTH = 2,
parameter C_DIN_WIDTH = 8,
parameter C_DOUT_RST_VAL = "",
parameter C_DOUT_WIDTH = 8,
parameter C_FULL_FLAGS_RST_VAL = 1,
parameter C_HAS_ALMOST_EMPTY = 0,
parameter C_HAS_ALMOST_FULL = 0,
parameter C_HAS_DATA_COUNT = 0,
parameter C_HAS_OVERFLOW = 0,
parameter C_HAS_RD_DATA_COUNT = 0,
parameter C_HAS_RST = 0,
parameter C_HAS_SRST = 0,
parameter C_HAS_UNDERFLOW = 0,
parameter C_HAS_VALID = 0,
parameter C_HAS_WR_ACK = 0,
parameter C_HAS_WR_DATA_COUNT = 0,
parameter C_IMPLEMENTATION_TYPE = 0,
parameter C_MEMORY_TYPE = 1,
parameter C_OVERFLOW_LOW = 0,
parameter C_PRELOAD_LATENCY = 1,
parameter C_PRELOAD_REGS = 0,
parameter C_PROG_EMPTY_THRESH_ASSERT_VAL = 0,
parameter C_PROG_EMPTY_THRESH_NEGATE_VAL = 0,
parameter C_PROG_EMPTY_TYPE = 0,
parameter C_PROG_FULL_THRESH_ASSERT_VAL = 0,
parameter C_PROG_FULL_THRESH_NEGATE_VAL = 0,
parameter C_PROG_FULL_TYPE = 0,
parameter C_RD_DATA_COUNT_WIDTH = 2,
parameter C_RD_DEPTH = 256,
parameter C_RD_PNTR_WIDTH = 8,
parameter C_UNDERFLOW_LOW = 0,
parameter C_USE_DOUT_RST = 0,
parameter C_USE_EMBEDDED_REG = 0,
parameter C_USE_FWFT_DATA_COUNT = 0,
parameter C_VALID_LOW = 0,
parameter C_WR_ACK_LOW = 0,
parameter C_WR_DATA_COUNT_WIDTH = 2,
parameter C_WR_DEPTH = 256,
parameter C_WR_PNTR_WIDTH = 8,
parameter C_USE_ECC = 0,
parameter C_ENABLE_RST_SYNC = 1,
parameter C_ERROR_INJECTION_TYPE = 0
)
/**************************************************************************
* Declare Input and Output Ports
*************************************************************************/
(
//Inputs
input CLK,
input [C_DIN_WIDTH-1:0] DIN,
input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH,
input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_ASSERT,
input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_NEGATE,
input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH,
input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_ASSERT,
input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_NEGATE,
input RD_EN,
input RST,
input RST_FULL_GEN,
input RST_FULL_FF,
input SRST,
input WR_EN,
input INJECTDBITERR,
input INJECTSBITERR,
//Outputs
output ALMOST_EMPTY,
output ALMOST_FULL,
output reg [C_DATA_COUNT_WIDTH-1:0] DATA_COUNT,
output [C_DOUT_WIDTH-1:0] DOUT,
output EMPTY,
output FULL,
output OVERFLOW,
output PROG_EMPTY,
output PROG_FULL,
output VALID,
output UNDERFLOW,
output WR_ACK,
output SBITERR,
output DBITERR
);
/***************************************************************************
* Parameters used as constants
**************************************************************************/
//When RST is present, set FULL reset value to '1'.
//If core has no RST, make sure FULL powers-on as '0'.
//The reset value assignments for FULL, ALMOST_FULL, and PROG_FULL are not
//changed for v3.2(IP2_Im). When the core has Sync Reset, C_HAS_SRST=1 and C_HAS_RST=0.
// Therefore, during SRST, all the FULL flags reset to 0.
parameter C_HAS_FAST_FIFO = 0;
parameter C_FIFO_WR_DEPTH = C_WR_DEPTH;
parameter C_FIFO_RD_DEPTH = C_RD_DEPTH;
/**************************************************************************
* FIFO Contents Tracking and Data Count Calculations
*************************************************************************/
// Memory which will be used to simulate a FIFO
reg [C_DIN_WIDTH-1:0] memory[C_WR_DEPTH-1:0];
// Local parameters used to determine whether to inject ECC error or not
localparam SYMMETRIC_PORT = (C_DIN_WIDTH == C_DOUT_WIDTH) ? 1 : 0;
localparam ERR_INJECTION = (C_ERROR_INJECTION_TYPE != 0) ? 1 : 0;
localparam ENABLE_ERR_INJECTION = C_USE_ECC && SYMMETRIC_PORT && ERR_INJECTION;
// Array that holds the error injection type (single/double bit error) on
// a specific write operation, which is returned on read to corrupt the
// output data.
reg [1:0] ecc_err[C_WR_DEPTH-1:0];
//The amount of data stored in the FIFO at any time is given
// by num_bits.
//num_bits is calculated by from the total words in the FIFO.
reg [31:0] num_bits;
//The write pointer - tracks write operations
// (Works opposite to core: wr_ptr is a DOWN counter)
reg [31:0] wr_ptr;
//The write pointer - tracks read operations
// (Works opposite to core: rd_ptr is a DOWN counter)
reg [31:0] rd_ptr;
/**************************
* Data Count
*************************/
//Amount of data stored in the FIFO scaled to read words
wire [31:0] num_read_words = num_bits/C_DOUT_WIDTH;
//num_read_words delayed 1 clock cycle
reg [31:0] num_read_words_q;
//Amount of data stored in the FIFO scaled to write words
wire [31:0] num_write_words = num_bits/C_DIN_WIDTH;
//num_write_words delayed 1 clock cycle
reg [31:0] num_write_words_q;
/**************************************************************************
* Internal Registers and wires
*************************************************************************/
//Temporary signals used for calculating the model's outputs. These
//are only used in the assign statements immediately following wire,
//parameter, and function declarations.
wire underflow_i;
wire valid_i;
wire valid_out;
//Ideal FIFO signals. These are the raw output of the behavioral model,
//which behaves like an ideal FIFO.
reg [1:0] err_type = 0;
reg [1:0] err_type_d1 = 0;
reg [C_DOUT_WIDTH-1:0] ideal_dout = 0;
reg [C_DOUT_WIDTH-1:0] ideal_dout_d1 = 0;
wire [C_DOUT_WIDTH-1:0] ideal_dout_out;
wire fwft_enabled;
reg ideal_wr_ack = 0;
reg ideal_valid = 0;
reg ideal_overflow = 0;
reg ideal_underflow = 0;
reg ideal_full = 0;
reg ideal_empty = 1;
reg ideal_almost_full = 0;
reg ideal_almost_empty = 1;
reg ideal_prog_full = 0;
reg ideal_prog_empty = 1;
//Assorted reg values for delayed versions of signals
reg valid_d1 = 0;
reg prog_full_d = 0;
reg prog_empty_d = 1;
wire rst_i;
wire srst_i;
//Delayed version of RST
reg rst_q;
reg rst_qq;
//user specified value for reseting the size of the fifo
reg [C_DOUT_WIDTH-1:0] dout_reset_val = 0;
/****************************************************************************
* Function Declarations
***************************************************************************/
/**************************************************************************
* write_fifo
* This task writes a word to the FIFO memory and updates the
* write pointer.
* FIFO size is relative to write domain.
***************************************************************************/
task write_fifo;
reg [1:0] corrupted_data;
begin
memory[wr_ptr] <= DIN;
// Store the type of error injection (double/single) on write
case (C_ERROR_INJECTION_TYPE)
3: ecc_err[wr_ptr] <= {INJECTDBITERR,INJECTSBITERR};
2: ecc_err[wr_ptr] <= {INJECTDBITERR,1'b0};
1: ecc_err[wr_ptr] <= {1'b0,INJECTSBITERR};
default: ecc_err[wr_ptr] <= 0;
endcase
if (wr_ptr == 0) begin
wr_ptr <= C_WR_DEPTH - 1;
end else begin
wr_ptr <= wr_ptr - 1;
end
end
endtask // write_fifo
/**************************************************************************
* read_fifo
* This task reads a word from the FIFO memory and updates the read
* pointer. It's output is the ideal_dout bus.
* FIFO size is relative to write domain.
***************************************************************************/
task read_fifo;
reg [C_DOUT_WIDTH-1:0] tmp_dout;
reg [1:0] tmp_ecc_err;
begin
tmp_dout = memory[rd_ptr][C_DOUT_WIDTH-1:0];
// Retreive the error injection type. Based on the error injection type
// corrupt the output data.
tmp_ecc_err = ecc_err[rd_ptr];
if (ENABLE_ERR_INJECTION) begin
if (tmp_ecc_err[1]) begin // Corrupt the output data only for double bit error
if (C_DOUT_WIDTH == 1)
tmp_dout = tmp_dout[C_DOUT_WIDTH-1:0];
else if (C_DOUT_WIDTH == 2)
tmp_dout = {~tmp_dout[C_DOUT_WIDTH-1],~tmp_dout[C_DOUT_WIDTH-2]};
else
tmp_dout = {~tmp_dout[C_DOUT_WIDTH-1],~tmp_dout[C_DOUT_WIDTH-2],(tmp_dout << 2)};
end else begin
tmp_dout = tmp_dout[C_DOUT_WIDTH-1:0];
end
err_type <= {tmp_ecc_err[1], tmp_ecc_err[0] & !tmp_ecc_err[1]};
end else begin
err_type <= 0;
end
ideal_dout <= tmp_dout;
if (rd_ptr == 0) begin
rd_ptr <= C_RD_DEPTH - 1;
end else begin
rd_ptr <= rd_ptr - 1;
end
end
endtask
/****************************************************************************
* log2_val
* Returns the 'log2' value for the input value for the supported ratios
***************************************************************************/
function [31:0] log2_val;
input [31:0] binary_val;
begin
if (binary_val == 8) begin
log2_val = 3;
end else if (binary_val == 4) begin
log2_val = 2;
end else begin
log2_val = 1;
end
end
endfunction
/****************************************************************************
* hexstr_conv
* Converts a string of type hex to a binary value (for C_DOUT_RST_VAL)
***************************************************************************/
function [C_DOUT_WIDTH-1:0] hexstr_conv;
input [(C_DOUT_WIDTH*8)-1:0] def_data;
integer index,i,j;
reg [3:0] bin;
begin
index = 0;
hexstr_conv = 'b0;
for( i=C_DOUT_WIDTH-1; i>=0; i=i-1 )
begin
case (def_data[7:0])
8'b00000000 :
begin
bin = 4'b0000;
i = -1;
end
8'b00110000 : bin = 4'b0000;
8'b00110001 : bin = 4'b0001;
8'b00110010 : bin = 4'b0010;
8'b00110011 : bin = 4'b0011;
8'b00110100 : bin = 4'b0100;
8'b00110101 : bin = 4'b0101;
8'b00110110 : bin = 4'b0110;
8'b00110111 : bin = 4'b0111;
8'b00111000 : bin = 4'b1000;
8'b00111001 : bin = 4'b1001;
8'b01000001 : bin = 4'b1010;
8'b01000010 : bin = 4'b1011;
8'b01000011 : bin = 4'b1100;
8'b01000100 : bin = 4'b1101;
8'b01000101 : bin = 4'b1110;
8'b01000110 : bin = 4'b1111;
8'b01100001 : bin = 4'b1010;
8'b01100010 : bin = 4'b1011;
8'b01100011 : bin = 4'b1100;
8'b01100100 : bin = 4'b1101;
8'b01100101 : bin = 4'b1110;
8'b01100110 : bin = 4'b1111;
default :
begin
bin = 4'bx;
end
endcase
for( j=0; j<4; j=j+1)
begin
if ((index*4)+j < C_DOUT_WIDTH)
begin
hexstr_conv[(index*4)+j] = bin[j];
end
end
index = index + 1;
def_data = def_data >> 8;
end
end
endfunction
/*************************************************************************
* Initialize Signals for clean power-on simulation
*************************************************************************/
initial begin
num_bits = 0;
num_read_words_q = 0;
num_write_words_q = 0;
rd_ptr = C_RD_DEPTH -1;
wr_ptr = C_WR_DEPTH -1;
dout_reset_val = hexstr_conv(C_DOUT_RST_VAL);
ideal_dout = dout_reset_val;
err_type = 0;
ideal_wr_ack = 1'b0;
ideal_valid = 1'b0;
valid_d1 = 1'b0;
ideal_overflow = 1'b0;
ideal_underflow = 1'b0;
ideal_full = 1'b0;
ideal_empty = 1'b1;
ideal_almost_full = 1'b0;
ideal_almost_empty = 1'b1;
ideal_prog_full = 1'b0;
ideal_prog_empty = 1'b1;
prog_full_d = 1'b0;
prog_empty_d = 1'b1;
rst_q = 1'b0;
rst_qq = 1'b0;
end
/*************************************************************************
* Connect the module inputs and outputs to the internal signals of the
* behavioral model.
*************************************************************************/
//Inputs
/*
wire CLK;
wire [C_DIN_WIDTH-1:0] DIN;
wire [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH;
wire [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_ASSERT;
wire [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_NEGATE;
wire [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH;
wire [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_ASSERT;
wire [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_NEGATE;
wire RD_EN;
wire RST;
wire WR_EN;
*/
//Outputs
generate
if (C_HAS_ALMOST_EMPTY==1) begin : blockAE10
assign ALMOST_EMPTY = ideal_almost_empty;
end
endgenerate
generate
if (C_HAS_ALMOST_FULL==1) begin : blockAF10
assign ALMOST_FULL = ideal_almost_full;
end
endgenerate
//Dout may change behavior based on latency
assign fwft_enabled = (C_PRELOAD_LATENCY == 0 && C_PRELOAD_REGS == 1)?
1: 0;
assign ideal_dout_out= ((C_USE_EMBEDDED_REG==1 && (fwft_enabled == 0)) &&
(C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1))?
ideal_dout_d1: ideal_dout;
assign DOUT = ideal_dout_out;
// Assign SBITERR and DBITERR based on latency
assign SBITERR = (C_ERROR_INJECTION_TYPE == 1 || C_ERROR_INJECTION_TYPE == 3) &&
((C_USE_EMBEDDED_REG==1 && (fwft_enabled == 0)) &&
(C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1)) ?
err_type_d1[0]: err_type[0];
assign DBITERR = (C_ERROR_INJECTION_TYPE == 2 || C_ERROR_INJECTION_TYPE == 3) &&
((C_USE_EMBEDDED_REG==1 && (fwft_enabled == 0)) &&
(C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1)) ?
err_type_d1[1]: err_type[1];
assign EMPTY = ideal_empty;
assign FULL = ideal_full;
//Overflow may be active-low
generate
if (C_HAS_OVERFLOW==1) begin : blockOF10
assign OVERFLOW = ideal_overflow ? !C_OVERFLOW_LOW : C_OVERFLOW_LOW;
end
endgenerate
assign PROG_EMPTY = ideal_prog_empty;
assign PROG_FULL = ideal_prog_full;
//Valid may change behavior based on latency or active-low
generate
if (C_HAS_VALID==1) begin : blockVL10
assign valid_i = (C_PRELOAD_LATENCY==0) ? (RD_EN & ~EMPTY) : ideal_valid;
assign valid_out = (C_PRELOAD_LATENCY==2 &&
(C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1))?
valid_d1: valid_i;
assign VALID = valid_out ? !C_VALID_LOW : C_VALID_LOW;
end
endgenerate
//Trim data count differently depending on set widths
generate
if ((C_HAS_DATA_COUNT == 1) &&
(C_DATA_COUNT_WIDTH > C_RD_PNTR_WIDTH)) begin : blockDC1
always @(num_read_words)
DATA_COUNT = num_read_words[C_RD_PNTR_WIDTH:0];
end else if (C_HAS_DATA_COUNT == 1) begin : blockDC2
always @(num_read_words)
DATA_COUNT = num_read_words[C_RD_PNTR_WIDTH-1:C_RD_PNTR_WIDTH-C_DATA_COUNT_WIDTH];
end //if
endgenerate
//Underflow may change behavior based on latency or active-low
generate
if (C_HAS_UNDERFLOW==1) begin : blockUF10
assign underflow_i = ideal_underflow;
assign UNDERFLOW = underflow_i ? !C_UNDERFLOW_LOW : C_UNDERFLOW_LOW;
end
endgenerate
//Write acknowledge may be active low
generate
if (C_HAS_WR_ACK==1) begin : blockWK10
assign WR_ACK = ideal_wr_ack ? !C_WR_ACK_LOW : C_WR_ACK_LOW;
end
endgenerate
/*****************************************************************************
* Internal reset logic
****************************************************************************/
assign srst_i = C_HAS_SRST ? SRST : 0;
assign rst_i = C_HAS_RST ? RST : 0;
/**************************************************************************
* Assorted registers for delayed versions of signals
**************************************************************************/
//Capture delayed version of valid
generate
if (C_HAS_VALID==1) begin : blockVL20
always @(posedge CLK or posedge rst_i) begin
if (rst_i == 1'b1) begin
valid_d1 <= #`TCQ 1'b0;
end else begin
if (srst_i) begin
valid_d1 <= #`TCQ 1'b0;
end else begin
valid_d1 <= #`TCQ valid_i;
end
end
end // always @ (posedge CLK or posedge rst_i)
end
endgenerate
// block memory has a synchronous reset
always @(posedge CLK) begin : gen_fifo_blkmemdout_emb
// make it consistent with the core.
if (rst_i || srst_i) begin
// BRAM resets synchronously
if (C_USE_DOUT_RST == 1 && C_MEMORY_TYPE < 2) begin
ideal_dout_d1 <= #`TCQ dout_reset_val;
end
end
end //always
reg ram_rd_en_d1 = 1'b0;
//Capture delayed version of dout
always @(posedge CLK or posedge rst_i) begin
if (rst_i == 1'b1) begin
// Reset err_type only if ECC is not selected
if (C_USE_ECC == 0)
err_type_d1 <= #`TCQ 0;
// DRAM and SRAM reset asynchronously
if ((C_MEMORY_TYPE == 2 || C_MEMORY_TYPE == 3) && C_USE_DOUT_RST == 1)
ideal_dout_d1 <= #`TCQ dout_reset_val;
ram_rd_en_d1 <= #`TCQ 1'b0;
end else begin
ram_rd_en_d1 <= #`TCQ RD_EN & !EMPTY;
if (srst_i) begin
ram_rd_en_d1 <= #`TCQ 1'b0;
// Reset err_type only if ECC is not selected
if (C_USE_ECC == 0)
err_type_d1 <= #`TCQ 0;
// Reset DRAM and SRAM based FIFO, BRAM based FIFO is reset above
if ((C_MEMORY_TYPE == 2 || C_MEMORY_TYPE == 3) && C_USE_DOUT_RST == 1)
ideal_dout_d1 <= #`TCQ dout_reset_val;
end else if (ram_rd_en_d1) begin
ideal_dout_d1 <= #`TCQ ideal_dout;
err_type_d1 <= #`TCQ err_type;
end
end
end
/**************************************************************************
* Overflow and Underflow Flag calculation
* (handled separately because they don't support rst)
**************************************************************************/
generate
if (C_HAS_OVERFLOW==1) begin : blockOF20
always @(posedge CLK) begin
ideal_overflow <= #`TCQ WR_EN & ideal_full;
end
end
endgenerate
generate
if (C_HAS_UNDERFLOW==1) begin : blockUF20
always @(posedge CLK) begin
ideal_underflow <= #`TCQ ideal_empty & RD_EN;
end
end
endgenerate
/*************************************************************************
* Write and Read Logic
************************************************************************/
always @(posedge CLK or posedge rst_i)
begin : gen_wr_ack_resp
//Register reset
rst_q <= #`TCQ rst_i;
rst_qq <= #`TCQ rst_q;
end // block: gen_wr_ack_resp
// block memory has a synchronous reset
always @(posedge CLK) begin : gen_fifo_blkmemdout
//Changed the latency of during async reset to '1' instead of '2' to
// make it consistent with the core.
if (rst_i || rst_q || srst_i) begin
// Reset err_type only if ECC is not selected
if (C_USE_ECC == 0 && C_MEMORY_TYPE == 1)
err_type <= #`TCQ 0;
/******Initialize Read Domain Signals*********************************/
if (C_USE_DOUT_RST == 1 && C_MEMORY_TYPE < 2) begin
ideal_dout <= #`TCQ dout_reset_val;
end
end
end //always
// FULL_FLAG_RESET value given for SRST as well.
reg srst_i_d1 = 0;
reg srst_i_d2 = 0;
always @(posedge CLK or posedge RST_FULL_FF) begin : gen_fifo
/****** Reset fifo - Asynchronous Reset**********************************/
//Changed the latency of during async reset to '1' instead of '2' to
// make it consistent with the core.
if (RST_FULL_FF) begin //v3.2
/******Initialize Generic FIFO constructs*****************************/
num_bits <= #`TCQ 0;
wr_ptr <= #`TCQ C_WR_DEPTH - 1;
rd_ptr <= #`TCQ C_RD_DEPTH - 1;
num_read_words_q <= #`TCQ 0;
num_write_words_q <= #`TCQ 0;
// Reset err_type only if ECC is not selected
if (C_USE_ECC == 0 && C_MEMORY_TYPE != 1)
err_type <= #`TCQ 0;
/******Initialize Write Domain Signals********************************/
ideal_wr_ack <= #`TCQ 0;
ideal_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
ideal_almost_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
/******Initialize Read Domain Signals*********************************/
// DRAM and SRAM reset asynchronously
if (C_USE_DOUT_RST == 1 && (C_MEMORY_TYPE == 2 || C_MEMORY_TYPE == 3)) begin
ideal_dout <= #`TCQ dout_reset_val;
end
ideal_valid <= #`TCQ 1'b0;
ideal_empty <= #`TCQ 1'b1;
ideal_almost_empty <= #`TCQ 1'b1;
end else begin
// Register SRST twice to be consistant with RST behavior
srst_i_d1 <= #`TCQ srst_i;
srst_i_d2 <= #`TCQ srst_i_d1;
if (srst_i) begin
// SRST is available only for Sync BRAM, DRAM and SRAM.
if (C_MEMORY_TYPE == 1 || C_MEMORY_TYPE == 2 || C_MEMORY_TYPE == 3) begin
/******Initialize Generic FIFO constructs***********************/
num_bits <= #`TCQ 0;
wr_ptr <= #`TCQ C_WR_DEPTH - 1;
rd_ptr <= #`TCQ C_RD_DEPTH - 1;
num_read_words_q <= #`TCQ 0;
num_write_words_q <= #`TCQ 0;
// Reset err_type only if ECC is not selected
if (C_USE_ECC == 0)
err_type <= #`TCQ 0;
/******Initialize Write Domain Signals**************************/
ideal_wr_ack <= #`TCQ 0;
ideal_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
ideal_almost_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
/******Initialize Read Domain Signals***************************/
//Reset DOUT of Sync DRAM/Shift RAM. Sync BRAM DOUT was reset in the
// above always block.
if (C_USE_DOUT_RST == 1 && (C_MEMORY_TYPE == 2 || C_MEMORY_TYPE == 3)) begin
ideal_dout <= #`TCQ dout_reset_val;
end
ideal_valid <= #`TCQ 1'b0;
ideal_empty <= #`TCQ 1'b1;
ideal_almost_empty <= #`TCQ 1'b1;
end
end else if ((srst_i_d1 || srst_i_d2) && (C_FULL_FLAGS_RST_VAL == 1)) begin //Hold full flag reset value set during RST/SRST
ideal_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
ideal_almost_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
end else begin //normal operating conditions
/********************************************************************/
// Synchronous FIFO Condition #1 : Writing and not reading
/********************************************************************/
ideal_valid <= #`TCQ 1'b0;
if (WR_EN & ~RD_EN) begin
/*********************************/
//If the FIFO is full, do NOT perform the write,
// update flags accordingly
/*********************************/
if (num_write_words >= C_FIFO_WR_DEPTH) begin
ideal_wr_ack <= #`TCQ 0;
//still full
ideal_full <= #`TCQ 1'b1;
ideal_almost_full <= #`TCQ 1'b1;
//write unsuccessful - do not change contents
// no read attempted
ideal_valid <= #`TCQ 1'b0;
//Not near empty
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
/*********************************/
//If the FIFO is reporting FULL
// (Startup condition)
/*********************************/
end else if ((num_write_words < C_FIFO_WR_DEPTH) && (ideal_full == 1'b1)) begin
ideal_wr_ack <= #`TCQ 0;
//still full
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//write unsuccessful - do not change contents
// no read attempted
ideal_valid <= #`TCQ 1'b0;
//FIFO EMPTY in this state can not be determined
//ideal_empty <= 1'b0;
//ideal_almost_empty <= 1'b0;
/*********************************/
//If the FIFO is one from full
/*********************************/
end else if (num_write_words == C_FIFO_WR_DEPTH-1) begin
//good write
ideal_wr_ack <= #`TCQ 1;
//FIFO is one from FULL and going FULL
ideal_full <= #`TCQ 1'b1;
ideal_almost_full <= #`TCQ 1'b1;
//Add input data
write_fifo;
// no read attempted
ideal_valid <= #`TCQ 1'b0;
//Not near empty
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
num_bits <= num_bits + C_DIN_WIDTH;
/*********************************/
//If the FIFO is 2 from full
/*********************************/
end else if (num_write_words == C_FIFO_WR_DEPTH-2) begin
//good write
ideal_wr_ack <= #`TCQ 1;
//2 from full, and writing, so set almost_full
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b1;
//Add input data
write_fifo;
//no read attempted
ideal_valid <= #`TCQ 1'b0;
//Not near empty
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
num_bits <= #`TCQ num_bits + C_DIN_WIDTH;
/*********************************/
//If the FIFO is ALMOST EMPTY
/*********************************/
end else if (num_read_words == 1) begin
//good write
ideal_wr_ack <= #`TCQ 1;
//Not near FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//Add input data
write_fifo;
// no read attempted
ideal_valid <= #`TCQ 1'b0;
//Leaving ALMOST_EMPTY
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
num_bits <= #`TCQ num_bits + C_DIN_WIDTH;
/*********************************/
//If the FIFO is EMPTY
/*********************************/
end else if (num_read_words == 0) begin
// good write
ideal_wr_ack <= #`TCQ 1;
//Not near FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//Add input data
write_fifo;
// no read attempted
ideal_valid <= #`TCQ 1'b0;
//Leaving EMPTY (still ALMOST_EMPTY)
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b1;
num_bits <= #`TCQ num_bits + C_DIN_WIDTH;
/*********************************/
//If the FIFO is not near EMPTY or FULL
/*********************************/
end else begin
// good write
ideal_wr_ack <= #`TCQ 1;
//Not near FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//Add input data
write_fifo;
// no read attempted
ideal_valid <= #`TCQ 1'b0;
//Not near EMPTY
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
num_bits <= #`TCQ num_bits + C_DIN_WIDTH;
end // average case
/******************************************************************/
// Synchronous FIFO Condition #2 : Reading and not writing
/******************************************************************/
end else if (~WR_EN & RD_EN) begin
/*********************************/
//If the FIFO is EMPTY
/*********************************/
if ((num_read_words == 0) || (ideal_empty == 1'b1)) begin
//no write attemped
ideal_wr_ack <= #`TCQ 0;
//FIFO is not near FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//Read will fail
ideal_valid <= #`TCQ 1'b0;
//FIFO is still empty
ideal_empty <= #`TCQ 1'b1;
ideal_almost_empty <= #`TCQ 1'b1;
//No read
/*********************************/
//If the FIFO is ALMOST EMPTY
/*********************************/
end else if (num_read_words == 1) begin
//no write attempted
ideal_wr_ack <= #`TCQ 0;
//FIFO is not near FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//Read successful
ideal_valid <= #`TCQ 1'b1;
//This read will make FIFO go empty
ideal_empty <= #`TCQ 1'b1;
ideal_almost_empty <= #`TCQ 1'b1;
//Get the data from the FIFO
read_fifo;
num_bits <= #`TCQ num_bits - C_DIN_WIDTH;
/*********************************/
//If the FIFO is 2 from EMPTY
/*********************************/
end else if (num_read_words == 2) begin
//no write attempted
ideal_wr_ack <= #`TCQ 0;
//FIFO is not near FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//Read successful
ideal_valid <= #`TCQ 1'b1;
//FIFO is going ALMOST_EMPTY
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b1;
//Get the data from the FIFO
read_fifo;
num_bits <= #`TCQ num_bits - C_DOUT_WIDTH;
/*********************************/
//If the FIFO is one from full
/*********************************/
end else if (num_write_words == C_FIFO_WR_DEPTH-1) begin
//no write attempted
ideal_wr_ack <= #`TCQ 0;
//FIFO is leaving ALMOST FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//Read successful
ideal_valid <= #`TCQ 1'b1;
//Not near empty
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
//Read from the FIFO
read_fifo;
num_bits <= #`TCQ num_bits - C_DOUT_WIDTH;
/*********************************/
// FIFO is FULL
/*********************************/
end else if (num_write_words >= C_FIFO_WR_DEPTH)
begin
//no write attempted
ideal_wr_ack <= #`TCQ 0;
//FIFO is leaving FULL, but is still ALMOST_FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b1;
//Read successful
ideal_valid <= #`TCQ 1'b1;
//Not near empty
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
//Read from the FIFO
read_fifo;
num_bits <= #`TCQ num_bits - C_DOUT_WIDTH;
/*********************************/
//If the FIFO is not near EMPTY or FULL
/*********************************/
end else begin
//no write attemped
ideal_wr_ack <= #`TCQ 0;
//Not near empty
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//Read successful
ideal_valid <= #`TCQ 1'b1;
//Not near empty
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
//Read from the FIFO
read_fifo;
num_bits <= #`TCQ num_bits - C_DOUT_WIDTH;
end // average read
/******************************************************************/
// Synchronous FIFO Condition #3 : Reading and writing
/******************************************************************/
end else if (WR_EN & RD_EN) begin
/*********************************/
// FIFO is FULL
/*********************************/
if (num_write_words >= C_FIFO_WR_DEPTH) begin
ideal_wr_ack <= #`TCQ 0;
//Read will be successful, so FIFO will leave FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b1;
//Read successful
ideal_valid <= #`TCQ 1'b1;
//Not near empty
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
//Read from the FIFO
read_fifo;
num_bits <= #`TCQ num_bits - C_DOUT_WIDTH;
/*********************************/
// FIFO is reporting FULL, but it is empty
// (This is a special case, when coming out of RST
/*********************************/
end else if ((num_write_words == 0) && (ideal_full == 1'b1)) begin
ideal_wr_ack <= #`TCQ 0;
//Read will be successful, so FIFO will leave FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//Read unsuccessful
ideal_valid <= #`TCQ 1'b0;
//Report empty condition
ideal_empty <= #`TCQ 1'b1;
ideal_almost_empty <= #`TCQ 1'b1;
//Do not read from empty FIFO
// Read from the FIFO
/*********************************/
//If the FIFO is one from full
/*********************************/
end else if (num_write_words == C_FIFO_WR_DEPTH-1) begin
//Write successful
ideal_wr_ack <= #`TCQ 1;
//FIFO will remain ALMOST_FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b1;
// put the data into the FIFO
write_fifo;
//Read successful
ideal_valid <= #`TCQ 1'b1;
//Not near empty
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
//Read from the FIFO
read_fifo;
num_bits <= #`TCQ num_bits + C_DIN_WIDTH - C_DOUT_WIDTH;
/*********************************/
//If the FIFO is ALMOST EMPTY
/*********************************/
end else if (num_read_words == 1) begin
//Write successful
ideal_wr_ack <= #`TCQ 1;
// Not near FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
// put the data into the FIFO
write_fifo;
//Read successful
ideal_valid <= #`TCQ 1'b1;
//FIFO will stay ALMOST_EMPTY
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b1;
//Read from the FIFO
read_fifo;
num_bits <= #`TCQ num_bits + C_DIN_WIDTH - C_DOUT_WIDTH;
/*********************************/
//If the FIFO is EMPTY
/*********************************/
end else if (num_read_words == 0) begin
//Write successful
ideal_wr_ack <= #`TCQ 1;
// Not near FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
// put the data into the FIFO
write_fifo;
//Read will fail
ideal_valid <= #`TCQ 1'b0;
//FIFO will leave EMPTY
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b1;
// No read
num_bits <= #`TCQ num_bits + C_DIN_WIDTH;
/*********************************/
//If the FIFO is not near EMPTY or FULL
/*********************************/
end else begin
//Write successful
ideal_wr_ack <= #`TCQ 1;
// Not near FULL
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
// put the data into the FIFO
write_fifo;
//Read successful
ideal_valid <= #`TCQ 1'b1;
// Not near EMPTY
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
//Read from the FIFO
read_fifo;
num_bits <= #`TCQ num_bits + C_DIN_WIDTH - C_DOUT_WIDTH;
end // average case
/******************************************************************/
// Synchronous FIFO Condition #4 : Not reading or writing
/******************************************************************/
end else begin
/*********************************/
// FIFO is FULL
/*********************************/
if (num_write_words >= C_FIFO_WR_DEPTH) begin
//No write
ideal_wr_ack <= #`TCQ 0;
ideal_full <= #`TCQ 1'b1;
ideal_almost_full <= #`TCQ 1'b1;
//No read
ideal_valid <= #`TCQ 1'b0;
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
//No change to memory
/*********************************/
//If the FIFO is one from full
/*********************************/
end else if (num_write_words == C_FIFO_WR_DEPTH-1) begin
//No write
ideal_wr_ack <= #`TCQ 0;
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b1;
//No read
ideal_valid <= #`TCQ 1'b0;
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
//No change to memory
/*********************************/
//If the FIFO is ALMOST EMPTY
/*********************************/
end else if (num_read_words == 1) begin
//No write
ideal_wr_ack <= #`TCQ 0;
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//No read
ideal_valid <= #`TCQ 1'b0;
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b1;
//No change to memory
end // almost empty
/*********************************/
//If the FIFO is EMPTY
/*********************************/
else if (num_read_words == 0)
begin
//No write
ideal_wr_ack <= #`TCQ 0;
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//No read
ideal_valid <= #`TCQ 1'b0;
ideal_empty <= #`TCQ 1'b1;
ideal_almost_empty <= #`TCQ 1'b1;
//No change to memory
/*********************************/
//If the FIFO is not near EMPTY or FULL
/*********************************/
end else begin
//No write
ideal_wr_ack <= #`TCQ 0;
ideal_full <= #`TCQ 1'b0;
ideal_almost_full <= #`TCQ 1'b0;
//No read
ideal_valid <= #`TCQ 1'b0;
ideal_empty <= #`TCQ 1'b0;
ideal_almost_empty <= #`TCQ 1'b0;
//No change to memory
end // average case
end // neither reading or writing
num_read_words_q <= #`TCQ num_read_words;
num_write_words_q <= #`TCQ num_write_words;
end //normal operating conditions
end
end // block: gen_fifo
always @(posedge CLK or posedge RST_FULL_FF) begin : gen_fifo_p
/****** Reset fifo - Async Reset****************************************/
//The latency of de-assertion of the flags is reduced by 1 to be
// consistent with the core.
if (RST_FULL_FF) begin
ideal_prog_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
ideal_prog_empty <= #`TCQ 1'b1;
prog_full_d <= #`TCQ C_FULL_FLAGS_RST_VAL;
prog_empty_d <= #`TCQ 1'b1;
end else begin
if (srst_i) begin
//SRST is available only for Sync BRAM and Sync DRAM. Not for SSHFT.
if (C_MEMORY_TYPE == 1 || C_MEMORY_TYPE == 2 || C_MEMORY_TYPE == 3) begin
ideal_prog_empty <= #`TCQ 1'b1;
prog_empty_d <= #`TCQ 1'b1;
ideal_prog_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
prog_full_d <= #`TCQ C_FULL_FLAGS_RST_VAL;
end
end else if ((srst_i_d1 || srst_i_d2) && (C_FULL_FLAGS_RST_VAL == 1)) begin
ideal_prog_full <= #`TCQ C_FULL_FLAGS_RST_VAL;
prog_full_d <= #`TCQ C_FULL_FLAGS_RST_VAL;
end else begin
/***************************************************************
* Programmable FULL flags
****************************************************************/
//calculation for standard fifo and latency =2
if (! (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) ) begin
//Single constant threshold
if (C_PROG_FULL_TYPE == 1) begin
if ((num_write_words >= C_PROG_FULL_THRESH_ASSERT_VAL-1)
&& WR_EN && !RD_EN) begin
prog_full_d <= #`TCQ 1'b1;
end else if (((num_write_words == C_PROG_FULL_THRESH_ASSERT_VAL)
&& RD_EN && !WR_EN) || (RST_FULL_GEN)) begin
prog_full_d <= #`TCQ 1'b0;
end
//Dual constant thresholds
end else if (C_PROG_FULL_TYPE == 2) begin
if ((num_write_words == C_PROG_FULL_THRESH_ASSERT_VAL-1)
&& WR_EN && !RD_EN) begin
prog_full_d <= #`TCQ 1'b1;
end else if ((num_write_words == C_PROG_FULL_THRESH_NEGATE_VAL)
&& RD_EN && !WR_EN) begin
prog_full_d <= #`TCQ 1'b0;
end
//Single input threshold
end else if (C_PROG_FULL_TYPE == 3) begin
if ((num_write_words == PROG_FULL_THRESH-1)
&& WR_EN && !RD_EN) begin
prog_full_d <= #`TCQ 1'b1;
end else if ((num_write_words == PROG_FULL_THRESH)
&& !WR_EN && RD_EN) begin
prog_full_d <= #`TCQ 1'b0;
end else if (num_write_words >= PROG_FULL_THRESH) begin
prog_full_d <= #`TCQ 1'b1;
end else if (num_write_words < PROG_FULL_THRESH) begin
prog_full_d <= #`TCQ 1'b0;
end
//Dual input thresholds
end else begin
if ((num_write_words == PROG_FULL_THRESH_ASSERT-1)
&& WR_EN && !RD_EN) begin
prog_full_d <= #`TCQ 1'b1;
end else if ((num_write_words == PROG_FULL_THRESH_NEGATE)
&& !WR_EN && RD_EN)begin
prog_full_d <= #`TCQ 1'b0;
end else if (num_write_words >= PROG_FULL_THRESH_ASSERT) begin
prog_full_d <= #`TCQ 1'b1;
end else if (num_write_words < PROG_FULL_THRESH_NEGATE) begin
prog_full_d <= #`TCQ 1'b0;
end
end
end // (~ (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) )
//calculation for FWFT fifo
if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin
if (C_PROG_FULL_TYPE == 1) begin
if ((num_write_words >= C_PROG_FULL_THRESH_ASSERT_VAL-1 - 2)
&& WR_EN && !RD_EN) begin
prog_full_d <= #`TCQ 1'b1;
end else if (((num_write_words == C_PROG_FULL_THRESH_ASSERT_VAL - 2)
&& RD_EN && !WR_EN) || (RST_FULL_GEN)) begin
prog_full_d <= #`TCQ 1'b0;
end
//Dual constant thresholds
end else if (C_PROG_FULL_TYPE == 2) begin
if ((num_write_words == C_PROG_FULL_THRESH_ASSERT_VAL-1 - 2)
&& WR_EN && !RD_EN) begin
prog_full_d <= #`TCQ 1'b1;
end else if ((num_write_words == C_PROG_FULL_THRESH_NEGATE_VAL - 2)
&& RD_EN && !WR_EN) begin
prog_full_d <= #`TCQ 1'b0;
end
//Single input threshold
end else if (C_PROG_FULL_TYPE == 3) begin
if ((num_write_words == PROG_FULL_THRESH-1 - 2)
&& WR_EN && !RD_EN) begin
prog_full_d <= #`TCQ 1'b1;
end else if ((num_write_words == PROG_FULL_THRESH - 2)
&& !WR_EN && RD_EN) begin
prog_full_d <= #`TCQ 1'b0;
end else if (num_write_words >= PROG_FULL_THRESH - 2) begin
prog_full_d <= #`TCQ 1'b1;
end else if (num_write_words < PROG_FULL_THRESH - 2) begin
prog_full_d <= #`TCQ 1'b0;
end
//Dual input thresholds
end else begin
if ((num_write_words == PROG_FULL_THRESH_ASSERT-1 - 2)
&& WR_EN && !RD_EN) begin
prog_full_d <= #`TCQ 1'b1;
end else if ((num_write_words == PROG_FULL_THRESH_NEGATE - 2)
&& !WR_EN && RD_EN)begin
prog_full_d <= #`TCQ 1'b0;
end else if (num_write_words >= PROG_FULL_THRESH_ASSERT - 2) begin
prog_full_d <= #`TCQ 1'b1;
end else if (num_write_words < PROG_FULL_THRESH_NEGATE - 2) begin
prog_full_d <= #`TCQ 1'b0;
end
end
end // (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0)
/*****************************************************************
* Programmable EMPTY flags
****************************************************************/
//calculation for standard fifo and latency = 2
if (! (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) ) begin
//Single constant threshold
if (C_PROG_EMPTY_TYPE == 1) begin
if ((num_read_words == C_PROG_EMPTY_THRESH_ASSERT_VAL+1)
&& RD_EN && !WR_EN) begin
prog_empty_d <= #`TCQ 1'b1;
end else if ((num_read_words == C_PROG_EMPTY_THRESH_ASSERT_VAL)
&& WR_EN && !RD_EN) begin
prog_empty_d <= #`TCQ 1'b0;
end
//Dual constant thresholds
end else if (C_PROG_EMPTY_TYPE == 2) begin
if ((num_read_words == C_PROG_EMPTY_THRESH_ASSERT_VAL+1)
&& RD_EN && !WR_EN) begin
prog_empty_d <= #`TCQ 1'b1;
end else if ((num_read_words == C_PROG_EMPTY_THRESH_NEGATE_VAL)
&& !RD_EN && WR_EN) begin
prog_empty_d <= #`TCQ 1'b0;
end
//Single input threshold
end else if (C_PROG_EMPTY_TYPE == 3) begin
if ((num_read_words == PROG_EMPTY_THRESH+1)
&& RD_EN && !WR_EN) begin
prog_empty_d <= #`TCQ 1'b1;
end else if ((num_read_words == PROG_EMPTY_THRESH)
&& !RD_EN && WR_EN) begin
prog_empty_d <= #`TCQ 1'b0;
end else if (num_read_words <= PROG_EMPTY_THRESH) begin
prog_empty_d <= #`TCQ 1'b1;
end else if (num_read_words > PROG_EMPTY_THRESH)begin
prog_empty_d <= #`TCQ 1'b0;
end
//Dual input thresholds
end else begin
if (num_read_words <= PROG_EMPTY_THRESH_ASSERT) begin
prog_empty_d <= #`TCQ 1'b1;
end else if ((num_read_words == PROG_EMPTY_THRESH_ASSERT+1)
&& RD_EN && !WR_EN) begin
prog_empty_d <= #`TCQ 1'b1;
end else if (num_read_words > PROG_EMPTY_THRESH_NEGATE)begin
prog_empty_d <= #`TCQ 1'b0;
end else if ((num_read_words == PROG_EMPTY_THRESH_NEGATE)
&& !RD_EN && WR_EN) begin
prog_empty_d <= #`TCQ 1'b0;
end
end
end // (~ (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) )
//calculation for FWFT fifo
if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin
//Single constant threshold
if (C_PROG_EMPTY_TYPE == 1) begin
if ((num_read_words == C_PROG_EMPTY_THRESH_ASSERT_VAL+1 - 2)
&& RD_EN && !WR_EN) begin
prog_empty_d <= #`TCQ 1'b1;
end else if ((num_read_words == C_PROG_EMPTY_THRESH_ASSERT_VAL - 2)
&& WR_EN && !RD_EN) begin
prog_empty_d <= #`TCQ 1'b0;
end
//Dual constant thresholds
end else if (C_PROG_EMPTY_TYPE == 2) begin
if ((num_read_words == C_PROG_EMPTY_THRESH_ASSERT_VAL+1 - 2)
&& RD_EN && !WR_EN) begin
prog_empty_d <= #`TCQ 1'b1;
end else if ((num_read_words == C_PROG_EMPTY_THRESH_NEGATE_VAL - 2)
&& !RD_EN && WR_EN) begin
prog_empty_d <= #`TCQ 1'b0;
end
//Single input threshold
end else if (C_PROG_EMPTY_TYPE == 3) begin
if ((num_read_words == PROG_EMPTY_THRESH+1 - 2)
&& RD_EN && !WR_EN) begin
prog_empty_d <= #`TCQ 1'b1;
end else if ((num_read_words == PROG_EMPTY_THRESH - 2)
&& !RD_EN && WR_EN) begin
prog_empty_d <= #`TCQ 1'b0;
end else if (num_read_words <= PROG_EMPTY_THRESH - 2) begin
prog_empty_d <= #`TCQ 1'b1;
end else if (num_read_words > PROG_EMPTY_THRESH - 2)begin
prog_empty_d <= #`TCQ 1'b0;
end
//Dual input thresholds
end else begin
if (num_read_words <= PROG_EMPTY_THRESH_ASSERT - 2) begin
prog_empty_d <= #`TCQ 1'b1;
end else if ((num_read_words == PROG_EMPTY_THRESH_ASSERT+1 - 2)
&& RD_EN && !WR_EN) begin
prog_empty_d <= #`TCQ 1'b1;
end else if (num_read_words > PROG_EMPTY_THRESH_NEGATE - 2)begin
prog_empty_d <= #`TCQ 1'b0;
end else if ((num_read_words == PROG_EMPTY_THRESH_NEGATE - 2)
&& !RD_EN && WR_EN) begin
prog_empty_d <= #`TCQ 1'b0;
end
end
end // (~ (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) )
ideal_prog_empty <= prog_empty_d;
if (RST_FULL_GEN) begin
ideal_prog_full <= #`TCQ 1'b0;
prog_full_d <= #`TCQ 1'b0;
end else begin
ideal_prog_full <= #`TCQ prog_full_d;
end
end //if (srst_i) begin
end //if (rst_i) begin
end //always @(posedge CLK or posedge rst_i) begin : gen_fifo_p
endmodule // fifo_generator_v6_1_bhv_ver_ss
/**************************************************************************
* First-Word Fall-Through module (preload 0)
**************************************************************************/
module fifo_generator_v6_1_bhv_ver_preload0
(
RD_CLK,
RD_RST,
SRST,
RD_EN,
FIFOEMPTY,
FIFODATA,
FIFOSBITERR,
FIFODBITERR,
USERDATA,
USERVALID,
USERUNDERFLOW,
USEREMPTY,
USERALMOSTEMPTY,
RAMVALID,
FIFORDEN,
USERSBITERR,
USERDBITERR
);
parameter C_DOUT_RST_VAL = "";
parameter C_DOUT_WIDTH = 8;
parameter C_HAS_RST = 0;
parameter C_ENABLE_RST_SYNC = 0;
parameter C_HAS_SRST = 0;
parameter C_USE_DOUT_RST = 0;
parameter C_USE_ECC = 0;
parameter C_USERVALID_LOW = 0;
parameter C_USERUNDERFLOW_LOW = 0;
parameter C_MEMORY_TYPE = 0;
//Inputs
input RD_CLK;
input RD_RST;
input SRST;
input RD_EN;
input FIFOEMPTY;
input [C_DOUT_WIDTH-1:0] FIFODATA;
input FIFOSBITERR;
input FIFODBITERR;
//Outputs
output [C_DOUT_WIDTH-1:0] USERDATA;
output USERVALID;
output USERUNDERFLOW;
output USEREMPTY;
output USERALMOSTEMPTY;
output RAMVALID;
output FIFORDEN;
output USERSBITERR;
output USERDBITERR;
//Inputs
wire RD_CLK;
wire RD_RST;
wire RD_EN;
wire FIFOEMPTY;
wire [C_DOUT_WIDTH-1:0] FIFODATA;
wire FIFOSBITERR;
wire FIFODBITERR;
//Outputs
reg [C_DOUT_WIDTH-1:0] USERDATA;
wire USERVALID;
wire USERUNDERFLOW;
wire USEREMPTY;
wire USERALMOSTEMPTY;
wire RAMVALID;
wire FIFORDEN;
reg USERSBITERR;
reg USERDBITERR;
//Internal signals
wire preloadstage1;
wire preloadstage2;
reg ram_valid_i;
reg read_data_valid_i;
wire ram_regout_en;
wire ram_rd_en;
reg empty_i = 1'b1;
reg empty_q = 1'b1;
reg rd_en_q = 1'b0;
reg almost_empty_i = 1'b1;
reg almost_empty_q = 1'b1;
wire rd_rst_i;
wire srst_i;
/*************************************************************************
* FUNCTIONS
*************************************************************************/
/*************************************************************************
* hexstr_conv
* Converts a string of type hex to a binary value (for C_DOUT_RST_VAL)
***********************************************************************/
function [C_DOUT_WIDTH-1:0] hexstr_conv;
input [(C_DOUT_WIDTH*8)-1:0] def_data;
integer index,i,j;
reg [3:0] bin;
begin
index = 0;
hexstr_conv = 'b0;
for( i=C_DOUT_WIDTH-1; i>=0; i=i-1 )
begin
case (def_data[7:0])
8'b00000000 :
begin
bin = 4'b0000;
i = -1;
end
8'b00110000 : bin = 4'b0000;
8'b00110001 : bin = 4'b0001;
8'b00110010 : bin = 4'b0010;
8'b00110011 : bin = 4'b0011;
8'b00110100 : bin = 4'b0100;
8'b00110101 : bin = 4'b0101;
8'b00110110 : bin = 4'b0110;
8'b00110111 : bin = 4'b0111;
8'b00111000 : bin = 4'b1000;
8'b00111001 : bin = 4'b1001;
8'b01000001 : bin = 4'b1010;
8'b01000010 : bin = 4'b1011;
8'b01000011 : bin = 4'b1100;
8'b01000100 : bin = 4'b1101;
8'b01000101 : bin = 4'b1110;
8'b01000110 : bin = 4'b1111;
8'b01100001 : bin = 4'b1010;
8'b01100010 : bin = 4'b1011;
8'b01100011 : bin = 4'b1100;
8'b01100100 : bin = 4'b1101;
8'b01100101 : bin = 4'b1110;
8'b01100110 : bin = 4'b1111;
default :
begin
bin = 4'bx;
end
endcase
for( j=0; j<4; j=j+1)
begin
if ((index*4)+j < C_DOUT_WIDTH)
begin
hexstr_conv[(index*4)+j] = bin[j];
end
end
index = index + 1;
def_data = def_data >> 8;
end
end
endfunction
//*************************************************************************
// Set power-on states for regs
//*************************************************************************
initial begin
ram_valid_i = 1'b0;
read_data_valid_i = 1'b0;
USERDATA = hexstr_conv(C_DOUT_RST_VAL);
USERSBITERR = 1'b0;
USERDBITERR = 1'b0;
end //initial
//***************************************************************************
// connect up optional reset
//***************************************************************************
assign rd_rst_i = (C_HAS_RST == 1 || C_ENABLE_RST_SYNC == 0) ? RD_RST : 0;
assign srst_i = C_HAS_SRST ? SRST : 0;
//***************************************************************************
// preloadstage2 indicates that stage2 needs to be updated. This is true
// whenever read_data_valid is false, and RAM_valid is true.
//***************************************************************************
assign preloadstage2 = ram_valid_i & (~read_data_valid_i | RD_EN);
//***************************************************************************
// preloadstage1 indicates that stage1 needs to be updated. This is true
// whenever the RAM has data (RAM_EMPTY is false), and either RAM_Valid is
// false (indicating that Stage1 needs updating), or preloadstage2 is active
// (indicating that Stage2 is going to update, so Stage1, therefore, must
// also be updated to keep it valid.
//***************************************************************************
assign preloadstage1 = ((~ram_valid_i | preloadstage2) & ~FIFOEMPTY);
//***************************************************************************
// Calculate RAM_REGOUT_EN
// The output registers are controlled by the ram_regout_en signal.
// These registers should be updated either when the output in Stage2 is
// invalid (preloadstage2), OR when the user is reading, in which case the
// Stage2 value will go invalid unless it is replenished.
//***************************************************************************
assign ram_regout_en = preloadstage2;
//***************************************************************************
// Calculate RAM_RD_EN
// RAM_RD_EN will be asserted whenever the RAM needs to be read in order to
// update the value in Stage1.
// One case when this happens is when preloadstage1=true, which indicates
// that the data in Stage1 or Stage2 is invalid, and needs to automatically
// be updated.
// The other case is when the user is reading from the FIFO, which
// guarantees that Stage1 or Stage2 will be invalid on the next clock
// cycle, unless it is replinished by data from the memory. So, as long
// as the RAM has data in it, a read of the RAM should occur.
//***************************************************************************
assign ram_rd_en = (RD_EN & ~FIFOEMPTY) | preloadstage1;
//***************************************************************************
// Calculate RAMVALID_P0_OUT
// RAMVALID_P0_OUT indicates that the data in Stage1 is valid.
//
// If the RAM is being read from on this clock cycle (ram_rd_en=1), then
// RAMVALID_P0_OUT is certainly going to be true.
// If the RAM is not being read from, but the output registers are being
// updated to fill Stage2 (ram_regout_en=1), then Stage1 will be emptying,
// therefore causing RAMVALID_P0_OUT to be false.
// Otherwise, RAMVALID_P0_OUT will remain unchanged.
//***************************************************************************
// PROCESS regout_valid
always @ (posedge RD_CLK or posedge rd_rst_i) begin
if (rd_rst_i) begin
// asynchronous reset (active high)
ram_valid_i <= #`TCQ 1'b0;
end else begin
if (srst_i) begin
// synchronous reset (active high)
ram_valid_i <= #`TCQ 1'b0;
end else begin
if (ram_rd_en == 1'b1) begin
ram_valid_i <= #`TCQ 1'b1;
end else begin
if (ram_regout_en == 1'b1)
ram_valid_i <= #`TCQ 1'b0;
else
ram_valid_i <= #`TCQ ram_valid_i;
end
end //srst_i
end //rd_rst_i
end //always
//***************************************************************************
// Calculate READ_DATA_VALID
// READ_DATA_VALID indicates whether the value in Stage2 is valid or not.
// Stage2 has valid data whenever Stage1 had valid data and
// ram_regout_en_i=1, such that the data in Stage1 is propogated
// into Stage2.
//***************************************************************************
always @ (posedge RD_CLK or posedge rd_rst_i) begin
if (rd_rst_i)
read_data_valid_i <= #`TCQ 1'b0;
else if (srst_i)
read_data_valid_i <= #`TCQ 1'b0;
else
read_data_valid_i <= #`TCQ ram_valid_i | (read_data_valid_i & ~RD_EN);
end //always
//**************************************************************************
// Calculate EMPTY
// Defined as the inverse of READ_DATA_VALID
//
// Description:
//
// If read_data_valid_i indicates that the output is not valid,
// and there is no valid data on the output of the ram to preload it
// with, then we will report empty.
//
// If there is no valid data on the output of the ram and we are
// reading, then the FIFO will go empty.
//
//**************************************************************************
always @ (posedge RD_CLK or posedge rd_rst_i) begin
if (rd_rst_i) begin
// asynchronous reset (active high)
empty_i <= #`TCQ 1'b1;
end else begin
if (srst_i) begin
// synchronous reset (active high)
empty_i <= #`TCQ 1'b1;
end else begin
// rising clock edge
empty_i <= #`TCQ (~ram_valid_i & ~read_data_valid_i) | (~ram_valid_i & RD_EN);
end
end
end //always
// Register RD_EN from user to calculate USERUNDERFLOW.
// Register empty_i to calculate USERUNDERFLOW.
always @ (posedge RD_CLK) begin
rd_en_q <= #`TCQ RD_EN;
empty_q <= #`TCQ empty_i;
end //always
//***************************************************************************
// Calculate user_almost_empty
// user_almost_empty is defined such that, unless more words are written
// to the FIFO, the next read will cause the FIFO to go EMPTY.
//
// In most cases, whenever the output registers are updated (due to a user
// read or a preload condition), then user_almost_empty will update to
// whatever RAM_EMPTY is.
//
// The exception is when the output is valid, the user is not reading, and
// Stage1 is not empty. In this condition, Stage1 will be preloaded from the
// memory, so we need to make sure user_almost_empty deasserts properly under
// this condition.
//***************************************************************************
always @ (posedge RD_CLK or posedge rd_rst_i)
begin
if (rd_rst_i) begin // asynchronous reset (active high)
almost_empty_i <= #`TCQ 1'b1;
almost_empty_q <= #`TCQ 1'b1;
end else begin // rising clock edge
if (srst_i) begin // synchronous reset (active high)
almost_empty_i <= #`TCQ 1'b1;
almost_empty_q <= #`TCQ 1'b1;
end else begin
if ((ram_regout_en) | (~FIFOEMPTY & read_data_valid_i & ~RD_EN)) begin
almost_empty_i <= #`TCQ FIFOEMPTY;
end
almost_empty_q <= #`TCQ empty_i;
end
end
end //always
assign USEREMPTY = empty_i;
assign USERALMOSTEMPTY = almost_empty_i;
assign FIFORDEN = ram_rd_en;
assign RAMVALID = ram_valid_i;
assign USERVALID = C_USERVALID_LOW ? ~read_data_valid_i : read_data_valid_i;
assign USERUNDERFLOW = C_USERUNDERFLOW_LOW ? ~(empty_q & rd_en_q) : empty_q & rd_en_q;
// BRAM resets synchronously
always @ (posedge RD_CLK)
begin
if (rd_rst_i || srst_i) begin
if (C_USE_DOUT_RST == 1 && C_MEMORY_TYPE < 2)
USERDATA <= #`TCQ hexstr_conv(C_DOUT_RST_VAL);
end
end //always
always @ (posedge RD_CLK or posedge rd_rst_i)
begin
if (rd_rst_i) begin //asynchronous reset (active high)
if (C_USE_ECC == 0) begin // Reset S/DBITERR only if ECC is OFF
USERSBITERR <= #`TCQ 0;
USERDBITERR <= #`TCQ 0;
end
// DRAM resets asynchronously
if (C_USE_DOUT_RST == 1 && C_MEMORY_TYPE == 2) //asynchronous reset (active high)
USERDATA <= #`TCQ hexstr_conv(C_DOUT_RST_VAL);
end else begin // rising clock edge
if (srst_i) begin
if (C_USE_ECC == 0) begin // Reset S/DBITERR only if ECC is OFF
USERSBITERR <= #`TCQ 0;
USERDBITERR <= #`TCQ 0;
end
if (C_USE_DOUT_RST == 1 && C_MEMORY_TYPE == 2)
USERDATA <= #`TCQ hexstr_conv(C_DOUT_RST_VAL);
end else begin
if (ram_regout_en) begin
USERDATA <= #`TCQ FIFODATA;
USERSBITERR <= #`TCQ FIFOSBITERR;
USERDBITERR <= #`TCQ FIFODBITERR;
end
end
end
end //always
endmodule
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