cvw/src/lsu/atomic.sv
2023-02-02 14:14:11 -08:00

60 lines
2.8 KiB
Systemverilog

///////////////////////////////////////////
// atomic.sv
//
// Written: Ross Thompson ross1728@gmail.com
// Created: 31 January 2022
// Modified: 18 January 2023
//
// Purpose: Wrapper for amoalu and lrsc
//
// Documentation: RISC-V System on Chip Design Chapter 14 (Figure ***)
//
// 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.
////////////////////////////////////////////////////////////////////////////////////////////////
`include "wally-config.vh"
module atomic (
input logic clk,
input logic reset,
input logic StallW,
input logic [`XLEN-1:0] ReadDataM, // LSU ReadData XLEN because FPU does not issue atomic memory operation from FPU registers
input logic [`XLEN-1:0] IHWriteDataM, // LSU WriteData XLEN because FPU does not issue atomic memory operation from FPU registers
input logic [`PA_BITS-1:0] PAdrM, // Physical memory address
input logic [6:0] LSUFunct7M, // AMO alu operation gated by HPTW
input logic [2:0] LSUFunct3M, // IEU or HPTW memory operation size
input logic [1:0] LSUAtomicM, // 10: AMO operation, select AMOResult as the writedata output, 01: LR/SC operation
input logic [1:0] PreLSURWM, // IEU or HPTW Read/Write signal
input logic IgnoreRequest, // On FlushM or TLB miss ignore memory operation
output logic [`XLEN-1:0] IMAWriteDataM, // IEU, HPTW, or AMO write data
output logic SquashSCW, // Store conditional failed disable write to GPR
output logic [1:0] LSURWM // IEU or HPTW Read/Write signal gated by LR/SC
);
logic [`XLEN-1:0] AMOResult;
logic MemReadM;
amoalu amoalu(.ReadDataM, .IHWriteDataM, .LSUFunct7M, .LSUFunct3M, .AMOResult);
mux2 #(`XLEN) wdmux(IHWriteDataM, AMOResult, LSUAtomicM[1], IMAWriteDataM);
assign MemReadM = PreLSURWM[1] & ~IgnoreRequest;
lrsc lrsc(.clk, .reset, .StallW, .MemReadM, .PreLSURWM, .LSUAtomicM, .PAdrM, .SquashSCW, .LSURWM);
endmodule