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/*
* f15_eoseq.v
*
* Resequence a data flow with data/valid/last ensuring EVEN/ODD
* sequencing (even data on even cycles, odd data on odd cycles)
*
* Copyright (C) 2014 Ettus Corporation LLC
* Copyright 2018 Ettus Research, a National Instruments Company
*
* SPDX-License-Identifier: LGPL-3.0-or-later
*
* vim: ts=4 sw=4
*/
`ifdef SIM
`default_nettype none
`endif
module f15_eoseq #(
parameter integer WIDTH = 16
)(
input wire [WIDTH-1:0] in_data,
input wire in_valid,
input wire in_last,
output reg [WIDTH-1:0] out_data,
output reg out_valid,
output reg out_last,
input wire clk,
input wire rst
);
// Signals
reg [WIDTH-1:0] buf_data;
reg buf_valid;
reg buf_last;
wire flip;
reg odd;
reg sel;
// Control
always @(posedge clk)
if (rst)
odd <= 1'b0;
else
odd <= ~(in_last & in_valid) & (odd ^ in_valid);
always @(posedge clk)
if (rst)
sel <= 1'b0;
else if (flip)
sel <= ~sel;
assign flip = ~in_valid | (in_last & ~odd);
// Buffer
always @(posedge clk)
begin
buf_data <= in_data;
buf_valid <= in_valid;
buf_last <= in_last;
end
// Output
always @(posedge clk)
begin
if (sel) begin
out_data <= buf_data;
out_valid <= buf_valid;
out_last <= buf_last;
end else begin
out_data <= in_data;
out_valid <= in_valid;
out_last <= in_last;
end
end
endmodule // f15_eoseq
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