cvw/src/ieu/bmu/bmuctrl.sv
2023-02-18 19:57:10 -08:00

135 lines
7.1 KiB
Systemverilog

///////////////////////////////////////////
// controller.sv
//
// Written: Kevin Kim <kekim@hmc.edu>
// Created: 16 February 2023
// Modified:
//
// Purpose: Top level B instrution controller module
//
// Documentation: RISC-V System on Chip Design Chapter 4 (Section 4.1.4, Figure 4.8, Table 4.5)
//
// 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"
// NOTE: DO we want to make this XLEN parameterized?
module bmuctrl(
input logic clk, reset,
// Decode stage control signals
input logic StallD, FlushD, // Stall, flush Decode stage
input logic [31:0] InstrD, // Instruction in Decode stage
output logic [2:0] ALUSelectD, // ALU Mux select signal
output logic [3:0] BSelectD, // Indicates if ZBA_ZBB_ZBC_ZBS instruction in one-hot encoding in Decode stage
output logic [2:0] ZBBSelectD, // ZBB mux select signal in Decode stage NOTE: do we need this in decode?
// Execute stage control signals
input logic StallE, FlushE, // Stall, flush Execute stage
output logic [2:0] ALUSelectE,
output logic [3:0] BSelectE, // Indicates if ZBA_ZBB_ZBC_ZBS instruction in one-hot encoding
output logic [2:0] ZBBSelectE // ZBB mux select signal
);
logic [6:0] OpD; // Opcode in Decode stage
logic [2:0] Funct3D; // Funct3 field in Decode stage
logic [6:0] Funct7D; // Funct7 field in Decode stage
logic [4:0] Rs2D; // Rs2 source register in Decode stage
`define BMUCTRLW 10
logic [`BMUCTRLW-1:0] BMUControlsD; // Main B Instructions Decoder control signals
// Extract fields
assign OpD = InstrD[6:0];
assign Funct3D = InstrD[14:12];
assign Funct7D = InstrD[31:25];
assign Rs2D = InstrD[24:20];
// Main Instruction Decoder
always_comb
casez({OpD, Funct7D, Funct3D})
// ALUSelect_BSelect_ZBBSelect
// ZBS
17'b0010011_0100100_001: BMUControlsD = `BMUCTRLW'b111_0001_000; // bclri
17'b0010011_0100101_001: if (`XLEN == 64)
BMUControlsD = `BMUCTRLW'b111_0001_000; // bclri (rv64)
else
BMUControlsD = `BMUCTRLW'b000_0000_000; // illegal instruction
17'b0010011_0100100_101: BMUControlsD = `BMUCTRLW'b101_0001_000; // bexti
17'b0010011_0100101_101: if (`XLEN == 64)
BMUControlsD = `BMUCTRLW'b101_0001_000; // bexti (rv64)
else
BMUControlsD = `BMUCTRLW'b000_0000_000; // illegal instruction
17'b0010011_0110100_001: BMUControlsD = `BMUCTRLW'b100_0001_000; // binvi
17'b0010011_0110101_001: if (`XLEN == 64)
BMUControlsD = `BMUCTRLW'b100_0001_000; // binvi (rv64)
else
BMUControlsD = `BMUCTRLW'b000_0000_000; // illegal instruction
17'b0010011_0010100_001: BMUControlsD = `BMUCTRLW'b110_0001_000; // bseti
17'b0010011_0010101_001: if (`XLEN == 64)
BMUControlsD = `BMUCTRLW'b110_0001_000; // bseti
else
BMUControlsD = `BMUCTRLW'b000_0000_000; // illegal instruction
17'b0110011_0100100_001: BMUControlsD = `BMUCTRLW'b111_0001_000; // bclr
17'b0110011_0100100_101: BMUControlsD = `BMUCTRLW'b101_0001_000; // bext
17'b0110011_0110100_001: BMUControlsD = `BMUCTRLW'b100_0001_000; // binv
17'b0110011_0010100_001: BMUControlsD = `BMUCTRLW'b110_0001_000; // bset
17'b0?1?011_0?0000?_?01: BMUControlsD = `BMUCTRLW'b001_0000_000; // sra, srai, srl, srli, sll, slli
// ZBC
17'b0110011_0000101_0??: BMUControlsD = `BMUCTRLW'b000_0010_000; // ZBC instruction
// ZBA
17'b0110011_0010000_010: BMUControlsD = `BMUCTRLW'b000_1000_000; // sh1add
17'b0110011_0010000_100: BMUControlsD = `BMUCTRLW'b000_1000_000; // sh2add
17'b0110011_0010000_110: BMUControlsD = `BMUCTRLW'b000_1000_000; // sh3add
17'b0111011_0010000_010: BMUControlsD = `BMUCTRLW'b000_1000_000; // sh1add.uw
17'b0111011_0010000_100: BMUControlsD = `BMUCTRLW'b000_1000_000; // sh2add.uw
17'b0111011_0010000_110: BMUControlsD = `BMUCTRLW'b000_1000_000; // sh3add.uw
17'b0111011_0000100_000: BMUControlsD = `BMUCTRLW'b000_1000_000; // add.uw
17'b0011011_000010?_001: BMUControlsD = `BMUCTRLW'b001_1000_000; // slli.uw
// ZBB
17'b0110011_0110000_001: BMUControlsD = `BMUCTRLW'b001_0100_111; // rol
17'b0111011_0110000_001: BMUControlsD = `BMUCTRLW'b001_0100_111; // rolw
17'b0110011_0110000_101: BMUControlsD = `BMUCTRLW'b001_0100_111; // ror
17'b0111011_0110000_101: BMUControlsD = `BMUCTRLW'b001_0100_111; // rorw
17'b0010011_0110000_101: BMUControlsD = `BMUCTRLW'b001_0100_111; // rori (rv32)
17'b0010011_0110001_101: if (`XLEN == 64)
BMUControlsD = `BMUCTRLW'b001_0100_111; // rori (rv64)
else
BMUControlsD = `BMUCTRLW'b000_0000_000; // illegal instruction
17'b0011011_0110000_101: if (`XLEN == 64)
BMUControlsD = `BMUCTRLW'b001_0100_111; // roriw
else
BMUControlsD = `BMUCTRLW'b000_0000_000; // illegal instruction
17'b0010011_0110000_001: if (Rs2D[2])
BMUControlsD = `BMUCTRLW'b000_0100_000; // count instruction
else
BMUControlsD = `BMUCTRLW'b000_0100_100; // sign ext instruction
default: BMUControlsD = {Funct3D, {7'b0}}; // not B instruction or shift
endcase
// Unpack Control Signals
assign {ALUSelectD,BSelectD,ZBBSelectD} = BMUControlsD;
// BMU Execute stage pipieline control register
flopenrc#(10) controlregBMU(clk, reset, FlushE, ~StallE, {ALUSelectD, BSelectD, ZBBSelectD}, {ALUSelectE, BSelectE, ZBBSelectE});
endmodule