added beginning of a ZBS instruction module to the ALU. Control signals still needed

This commit is contained in:
Kip Macsai-Goren 2023-02-01 21:31:25 -08:00
parent 5e607f7c82
commit f126d1e0ef
2 changed files with 63 additions and 0 deletions

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@ -32,6 +32,7 @@
module alu #(parameter WIDTH=32) (
input logic [WIDTH-1:0] A, B, // Operands
input logic [2:0] ALUControl, // With Funct3, indicates operation to perform
input logic [6:0] Funct7,
input logic [2:0] Funct3, // With ALUControl, indicates operation to perform
output logic [WIDTH-1:0] Result, // ALU result
output logic [WIDTH-1:0] Sum); // Sum of operands
@ -83,6 +84,10 @@ module alu #(parameter WIDTH=32) (
3'b111: FullResult = A & B; // and
endcase
if (`ZBS_SUPPORTED)
zbs zbs(.A, .B, .Funct7, .Funct3, .ZBSResult);
else assign ZBSResult = 0;
// Support RV64I W-type addw/subw/addiw/shifts that discard upper 32 bits and sign-extend 32-bit result to 64 bits
if (WIDTH == 64) assign Result = W64 ? {{32{FullResult[31]}}, FullResult[31:0]} : FullResult;
else assign Result = FullResult;

58
pipelined/src/ieu/zbs.sv Normal file
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@ -0,0 +1,58 @@
///////////////////////////////////////////
// zbs.sv
//
// Written: Kevin Kim <kekim@hmc.edu> and Kip Macsai-Goren <kmacsaigoren@hmc.edu>
// Created: 31 January 2023
// Modified:
//
// Purpose: RISC-V single bit manipulation unit (ZBS instructions)
//
// Documentation: RISC-V System on Chip Design Chapter ***
//
// 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 zbs #(parameter WIDTH=32) (
input logic [WIDTH-1:0] A, B, // Operands
//input logic [2:0] ALUControl, // With Funct3, indicates operation to perform
input logic [6:0] Funct7,
input logic [2:0] Funct3, // With ***Control, indicates operation to perform
output logic [WIDTH-1:0] ZBSResult); // ZBS result
//output logic [WIDTH-1:0] Sum); // Sum of operands
logic [WIDTH-1:0] BMask, ClrResult, InvResult, ExtResult, SetResult;
decoder #(clog2(WIDTH)) maskgen (B[$clog2(WIDTH)-1:0], BMask);
assign InvResult = A ^ BMask;
assign ClrResult = A & ~BMask;
assign SetResult = A | BMask;
assign ExtResult = |(A & BMask);
casez ({Funct7, Funct3})
10'b010010?_001: ZBSResult = ClrResult;
10'b010010?_101: ZBSResult = ExtResult;
10'b011010?_001: ZBSResult = ClrResult;
10'b001010?_001: ZBSResult = ClrResult;
default: ZBSResult = 0; // *** should never be reached or selected
endcase
endmodule