cvw/wally-pipelined/src/fpu/fregfile.sv
Katherine Parry 67ab0b165c fpu cleanup
2021-07-24 14:59:57 -04:00

55 lines
2.1 KiB
Systemverilog

///////////////////////////////////////////
// regfile.sv
//
// Written: David_Harris@hmc.edu 9 January 2021
// Modified:
//
// Purpose: 4-port register file
//
// A component of the Wally configurable RISC-V project.
//
// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
//
// 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.
///////////////////////////////////////////
`include "wally-config.vh"
module fregfile (
input logic clk, reset,
input logic we4,
input logic [ 4:0] a1, a2, a3, a4,
input logic [63:0] wd4,
output logic [63:0] rd1, rd2, rd3);
logic [63:0] rf[31:0];
integer i;
// three ported register file
// read three ports combinationally (A1/RD1, A2/RD2, A3/RD3)
// write fourth port on rising edge of clock (A4/WD4/WE4)
// write occurs on falling edge of clock
// reset is intended for simulation only, not synthesis
always_ff @(negedge clk or posedge reset)
if (reset) for(i=0; i<32; i++) rf[i] <= 0;
else if (we4) rf[a4] <= wd4;
assign #2 rd1 = rf[a1];
assign #2 rd2 = rf[a2];
assign #2 rd3 = rf[a3];
endmodule // regfile