cvw/pipelined/src/generic/mem/sram1p1rw.sv
2022-12-20 02:57:51 -08:00

88 lines
3.5 KiB
Systemverilog

///////////////////////////////////////////
// 1 port sram.
//
// Written: ross1728@gmail.com May 3, 2021
// Basic sram with 1 read write port.
// When clk rises Addr and LineWriteData are sampled.
// Following the clk edge read data is output from the sampled Addr.
// Write
//
// Purpose: Storage and read/write access to data cache data, tag valid, dirty, and replacement.
//
// A component of the Wally configurable RISC-V project.
//
// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
//
// MIT LICENSE
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
// OR OTHER DEALINGS IN THE SOFTWARE.
////////////////////////////////////////////////////////////////////////////////////////////////
// WIDTH is number of bits in one "word" of the memory, DEPTH is number of such words
`include "wally-config.vh"
module sram1p1rw #(parameter DEPTH=128, WIDTH=256) (
input logic clk,
input logic ce,
input logic [$clog2(DEPTH)-1:0] addr,
input logic [WIDTH-1:0] din,
input logic we,
input logic [(WIDTH-1)/8:0] bwe,
output logic [WIDTH-1:0] dout);
logic [WIDTH-1:0] RAM[DEPTH-1:0];
// ***************************************************************************
// TRUE SRAM macro
// ***************************************************************************
if (`USE_SRAM == 1) begin
genvar index;
// 64 x 128-bit SRAM
// check if the size is ok, complain if not***
logic [WIDTH-1:0] BitWriteMask;
for (index=0; index < WIDTH; index++)
assign BitWriteMask[index] = bwe[index/8];
TS1N28HPCPSVTB64X128M4SW sram(
.CLK(clk), .CEB(~ce), .WEB(~we),
.A(addr), .D(din),
.BWEB(~BitWriteMask), .Q(dout));
// ***************************************************************************
// READ first SRAM model
// ***************************************************************************
end else begin: ram
integer i;
// Read
always @(posedge clk)
if(ce) dout <= #1 RAM[addr];
// Write divided into part for bytes and part for extra msbs
if(WIDTH >= 8)
always @(posedge clk)
if (ce & we)
for(i = 0; i < WIDTH/8; i++)
if(bwe[i]) RAM[addr][i*8 +: 8] <= #1 din[i*8 +: 8];
if (WIDTH%8 != 0) // handle msbs if width not a multiple of 8
always @(posedge clk)
if (ce & we & bwe[WIDTH/8])
RAM[addr][WIDTH-1:WIDTH-WIDTH%8] <= #1 din[WIDTH-1:WIDTH-WIDTH%8];
end
endmodule