cvw/src/generic/mem/ram2p1r1wbe.sv
2023-02-15 18:12:12 -06:00

135 lines
4.9 KiB
Systemverilog

///////////////////////////////////////////
// 2 port sram.
//
// Written: ross1728@gmail.com May 3, 2021
// Two port SRAM 1 read port and 1 write port.
// When clk rises Addr and LineWriteData are sampled.
// Following the clk edge read data is output from the sampled Addr.
// Write
// Modified: james.stine@okstate.edu Feb 1, 2023
// Integration of memories
//
// Purpose: Storage and read/write access to data cache data, tag valid, dirty, and replacement.
//
// A component of the CORE-V-WALLY configurable RISC-V project.
//
// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
//
// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
//
// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file
// except in compliance with the License, or, at your option, the Apache License version 2.0. You
// may obtain a copy of the License at
//
// https://solderpad.org/licenses/SHL-2.1/
//
// Unless required by applicable law or agreed to in writing, any work distributed under the
// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
// either express or implied. See the License for the specific language governing permissions
// and limitations under the License.
////////////////////////////////////////////////////////////////////////////////////////////////
// WIDTH is number of bits in one "word" of the memory, DEPTH is number of such words
`include "wally-config.vh"
module ram2p1r1wbe #(parameter DEPTH=128, WIDTH=256) (
input logic clk,
input logic ce1, ce2,
input logic [$clog2(DEPTH)-1:0] ra1,
input logic [WIDTH-1:0] wd2,
input logic [$clog2(DEPTH)-1:0] wa2,
input logic we2,
input logic [(WIDTH-1)/8:0] bwe2,
output logic [WIDTH-1:0] rd1
);
logic [WIDTH-1:0] mem[DEPTH-1:0];
localparam SRAMWIDTH = 32;
localparam SRAMNUMSETS = SRAMWIDTH/WIDTH;
// ***************************************************************************
// TRUE Smem macro
// ***************************************************************************
if (`USE_SRAM == 1 && WIDTH == 68 && DEPTH == 1024) begin
ram2p1r1wbe_1024x68 memory1(.CLKA(clk), .CLKB(clk),
.CEBA(~ce1), .CEBB(~ce2),
.WEBA('0), .WEBB(~we2),
.AA(ra1), .AB(wa2),
.DA('0),
.DB(wd2),
.BWEBA('0), .BWEBB('1),
.QA(rd1),
.QB());
end else if (`USE_SRAM == 1 && WIDTH == 36 && DEPTH == 1024) begin
ram2p1r1wbe_1024x36 memory1(.CLKA(clk), .CLKB(clk),
.CEBA(~ce1), .CEBB(~ce2),
.WEBA('0), .WEBB(~we2),
.AA(ra1), .AB(wa2),
.DA('0),
.DB(wd2),
.BWEBA('0), .BWEBB('1),
.QA(rd1),
.QB());
end else if (`USE_SRAM == 1 && WIDTH == 2 && DEPTH == 1024) begin
logic [SRAMWIDTH-1:0] SRAMReadData;
logic [SRAMWIDTH-1:0] SRAMWriteData;
logic [SRAMWIDTH-1:0] RD1Sets[SRAMNUMSETS-1:0];
logic [SRAMNUMSETS-1:0] SRAMBitMaskPre;
logic [SRAMWIDTH-1:0] SRAMBitMask;
logic [$clog2(DEPTH)-1:0] RA1Q;
onehotdecoder #($clog2(SRAMNUMSETS)) oh1(wa2[$clog2(SRAMNUMSETS)-1:0], SRAMBitMaskPre);
genvar index;
for (index = 0; index < SRAMNUMSETS; index++) begin:readdatalinesetsmux
assign RD1Sets[index] = SRAMReadData[(index*WIDTH)+WIDTH-1 : (index*WIDTH)];
assign SRAMWriteData[index*2+1:index*2] = wd2;
assign SRAMBitMask[index*2+1:index*2] = {2{SRAMBitMaskPre[index]}};
end
flopen #($clog2(DEPTH)) mem_reg1 (clk, ce1, ra1, RA1Q);
assign rd1 = RD1Sets[RA1Q[$clog2(SRAMWIDTH)-1:0]];
ram2p1r1wbe_64x32 memory2(.CLKA(clk), .CLKB(clk),
.CEBA(~ce1), .CEBB(~ce2),
.WEBA('0), .WEBB(~we2),
.AA(ra1[$clog2(DEPTH)-1:$clog2(SRAMNUMSETS)]),
.AB(wa2[$clog2(DEPTH)-1:$clog2(SRAMNUMSETS)]),
.DA('0),
.DB(SRAMWriteData),
.BWEBA('0), .BWEBB(SRAMBitMask),
.QA(SRAMReadData),
.QB());
end else begin
// ***************************************************************************
// READ first SRAM model
// ***************************************************************************
integer i;
// Read
always_ff @(posedge clk)
if(ce1) rd1 <= #1 mem[ra1];
// Write divided into part for bytes and part for extra msbs
if(WIDTH >= 8)
always @(posedge clk)
if (ce2 & we2)
for(i = 0; i < WIDTH/8; i++)
if(bwe2[i]) mem[wa2][i*8 +: 8] <= #1 wd2[i*8 +: 8];
if (WIDTH%8 != 0) // handle msbs if width not a multiple of 8
always @(posedge clk)
if (ce2 & we2 & bwe2[WIDTH/8])
mem[wa2][WIDTH-1:WIDTH-WIDTH%8] <= #1 wd2[WIDTH-1:WIDTH-WIDTH%8];
end
endmodule