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//
// Copyright 2011 Ettus Research LLC
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// Since this is a block ram, there are no byte-selects and there is a 1-cycle read latency
// These have to be a multiple of 512 lines (2K) long
module wb_ram_block
#(parameter AWIDTH=9)
(input clk_i,
input stb_i,
input we_i,
input [AWIDTH-1:0] adr_i,
input [31:0] dat_i,
output reg [31:0] dat_o,
output ack_o);
reg [31:0] distram [0:1<<(AWIDTH-1)];
always @(posedge clk_i)
begin
if(stb_i & we_i)
distram[adr_i] <= dat_i;
dat_o <= distram[adr_i];
end
reg stb_d1, ack_d1;
always @(posedge clk_i)
stb_d1 <= stb_i;
always @(posedge clk_i)
ack_d1 <= ack_o;
assign ack_o = stb_i & (we_i | (stb_d1 & ~ack_d1));
endmodule // wb_ram_block
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