/* Copyright 2019 Blue Liang, liangkangnan@163.com Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software 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 "defines.v" // identification module module id ( input wire clk, input wire rst, input wire[`SramBus] inst_i, // inst content input wire[`SramAddrBus] inst_addr_i, // inst addr input wire jump_flag_ex_i, input wire hold_flag_ex_i, input wire int_flag_ex_i, input wire halt_flag_dm_i, // to regs output reg reg1_re_o, // reg1 read enable output reg[`RegAddrBus] reg1_raddr_o, // reg1 read addr output reg reg2_re_o, // reg2 read enable output reg[`RegAddrBus] reg2_raddr_o, // reg2 read addr output reg reg_we_o, // reg write enable output reg[`RegAddrBus] reg_waddr_o, // reg write addr // to ex output reg[`SramBus] inst_o, output reg inst_valid_o, // inst is valid flag output reg[`SramAddrBus] inst_addr_o, // to sram output reg sram_re_o, // ram read enable output reg sram_we_o // ram write enable ); wire[6:0] opcode = inst_i[6:0]; wire[2:0] funct3 = inst_i[14:12]; wire[6:0] funct7 = inst_i[31:25]; wire[4:0] rd = inst_i[11:7]; wire[4:0] rs1 = inst_i[19:15]; wire[4:0] rs2 = inst_i[24:20]; always @ (posedge clk) begin if (rst == `RstEnable) begin inst_o <= `ZeroWord; reg_we_o <= `WriteDisable; sram_we_o <= `WriteDisable; reg1_re_o <= `ReadDisable; reg2_re_o <= `ReadDisable; sram_re_o <= `ReadDisable; inst_valid_o <= `InstInvalid; end else if (halt_flag_dm_i == 1'b1) begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; inst_o <= `INST_NOP; end else if (int_flag_ex_i == 1'b1 && inst_i != `INST_NOP) begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; inst_o <= `INST_NOP; end else if (jump_flag_ex_i == `JumpEnable && inst_i != `INST_NOP) begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; inst_o <= `INST_NOP; end else if (hold_flag_ex_i == `HoldEnable) begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; inst_o <= `INST_NOP; end else begin inst_o <= inst_i; inst_addr_o <= inst_addr_i; case (opcode) `INST_TYPE_I: begin case (funct3) `INST_ADDI: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; sram_we_o <= `WriteDisable; end `INST_SLTI: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; sram_we_o <= `WriteDisable; end `INST_SLTIU: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; sram_we_o <= `WriteDisable; end `INST_XORI: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; sram_we_o <= `WriteDisable; end `INST_ORI: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; sram_we_o <= `WriteDisable; end `INST_ANDI: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; sram_we_o <= `WriteDisable; end `INST_SLLI: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; sram_we_o <= `WriteDisable; end `INST_SRI: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; sram_we_o <= `WriteDisable; end default: begin inst_valid_o <= `InstInvalid; end endcase end `INST_TYPE_R_M: begin if ((funct7 == 7'b0000000) || (funct7 == 7'b0100000)) begin case (funct3) `INST_ADD_SUB: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_SLL: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_SLT: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_SLTU: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_XOR: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_SR: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_OR: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_AND: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end default: begin inst_valid_o <= `InstInvalid; end endcase end else if (funct7 == 7'b0000001) begin case (funct3) `INST_MUL: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_MULHU: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_MULH: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_MULHSU: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_DIV: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteDisable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_DIVU: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteDisable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_REM: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteDisable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end `INST_REMU: begin inst_valid_o <= `InstValid; reg_we_o <= `WriteDisable; reg_waddr_o <= rd; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; end default: begin inst_valid_o <= `InstInvalid; end endcase end end `INST_TYPE_L: begin case (funct3) `INST_LB: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; sram_re_o <= `ReadEnable; sram_we_o <= `WriteDisable; end `INST_LH: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; sram_re_o <= `ReadEnable; sram_we_o <= `WriteDisable; end `INST_LW: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; sram_re_o <= `ReadEnable; sram_we_o <= `WriteDisable; end `INST_LBU: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; sram_re_o <= `ReadEnable; sram_we_o <= `WriteDisable; end `INST_LHU: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; sram_re_o <= `ReadEnable; sram_we_o <= `WriteDisable; end default: begin inst_valid_o <= `InstInvalid; end endcase end `INST_TYPE_S: begin case (funct3) `INST_SB: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteEnable; sram_re_o <= `ReadEnable; reg_we_o <= `WriteDisable; end `INST_SH: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteEnable; sram_re_o <= `ReadEnable; reg_we_o <= `WriteDisable; end `INST_SW: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_re_o <= `ReadEnable; reg2_raddr_o <= rs2; sram_we_o <= `WriteEnable; reg_we_o <= `WriteDisable; end default: begin inst_valid_o <= `InstInvalid; end endcase end `INST_TYPE_B: begin case (funct3) `INST_BEQ: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg2_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; end `INST_BNE: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg2_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; end `INST_BLT: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg2_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; end `INST_BGE: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg2_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; end `INST_BLTU: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg2_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; end `INST_BGEU: begin inst_valid_o <= `InstValid; reg1_re_o <= `ReadEnable; reg2_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg2_raddr_o <= rs2; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; end default: begin inst_valid_o <= `InstInvalid; end endcase end `INST_JAL: begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; end `INST_JALR: begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteEnable; reg1_re_o <= `ReadEnable; reg1_raddr_o <= rs1; reg_waddr_o <= rd; end `INST_LUI: begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; end `INST_AUIPC: begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteEnable; reg_waddr_o <= rd; end `INST_NOP: begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; end `INST_FENCE: begin inst_valid_o <= `InstValid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; end default: begin inst_valid_o <= `InstInvalid; sram_we_o <= `WriteDisable; reg_we_o <= `WriteDisable; end endcase end end endmodule