`ifndef RV32_DECODE `define RV32_DECODE `include "rv32_alu.sv" `include "rv32_branch.sv" `include "rv32_mem.sv" `include "rv32_opcodes.sv" `include "rv32_regs.sv" module rv32_decode ( input clk, /* control in (from hazard) */ input stall_in, input flush_in, /* control in (from writeback) */ input [4:0] rd_in, input rd_write_in, /* data in */ input [31:0] pc_in, input [31:0] instr_in, /* data in (from writeback) */ input [31:0] rd_value_in, /* control out (to hazard) */ output logic [4:0] rs1_unreg_out, output logic [4:0] rs2_unreg_out, /* control out */ output logic valid_out, output logic [4:0] rs1_out, output logic [4:0] rs2_out, output logic [3:0] alu_op_out, output logic alu_sub_sra_out, output logic alu_src1_out, output logic alu_src2_out, output logic mem_read_out, output logic mem_write_out, output logic [1:0] mem_width_out, output logic mem_zero_extend_out, output logic [1:0] branch_op_out, output logic branch_pc_src_out, output logic [4:0] rd_out, output logic rd_write_out, /* data out */ output logic [31:0] pc_out, output logic [31:0] rs1_value_out, output logic [31:0] rs2_value_out, output logic [31:0] imm_out ); logic [6:0] funct7; logic [4:0] rs2; logic [4:0] rs1; logic [2:0] funct3; logic [4:0] rd; logic [6:0] opcode; logic sign; logic [31:0] imm_i; logic [31:0] imm_s; logic [31:0] imm_b; logic [31:0] imm_u; logic [31:0] imm_j; logic [31:0] shamt; assign funct7 = instr_in[31:25]; assign rs2 = instr_in[24:20]; assign rs1 = instr_in[19:15]; assign funct3 = instr_in[14:12]; assign rd = instr_in[11:7]; assign opcode = instr_in[6:0]; assign sign = instr_in[31]; assign imm_i = {{21{sign}}, instr_in[30:25], instr_in[24:21], instr_in[20]}; assign imm_s = {{21{sign}}, instr_in[30:25], instr_in[11:8], instr_in[7]}; assign imm_b = {{20{sign}}, instr_in[7], instr_in[30:25], instr_in[11:8], 1'b0}; assign imm_u = {sign, instr_in[30:20], instr_in[19:12], 12'b0}; assign imm_j = {{12{sign}}, instr_in[19:12], instr_in[20], instr_in[30:25], instr_in[24:21], 1'b0}; assign shamt = {27'bx, rs2}; assign rs1_unreg_out = rs1; assign rs2_unreg_out = rs2; rv32_regs regs ( .clk(clk), .stall_in(stall_in), /* control in */ .rs1_in(rs1), .rs2_in(rs2), .rd_in(rd_in), .rd_write_in(rd_write_in), /* data in */ .rd_value_in(rd_value_in), /* data out */ .rs1_value_out(rs1_value_out), .rs2_value_out(rs2_value_out) ); always_ff @(posedge clk) begin if (!stall_in) begin valid_out <= 0; rs1_out <= rs1; rs2_out <= rs2; alu_op_out <= 4'bx; alu_sub_sra_out <= 1'bx; alu_src1_out <= 1'bx; alu_src2_out <= 1'bx; mem_read_out <= 0; mem_write_out <= 0; mem_width_out <= 2'bx; mem_zero_extend_out <= 1'bx; branch_op_out <= `RV32_BRANCH_OP_NEVER; branch_pc_src_out <= 1'bx; rd_out <= rd; rd_write_out <= 0; pc_out <= pc_in; imm_out <= 32'bx; casez ({opcode, funct3, funct7}) {`RV32_OPCODE_LUI, `RV32_FUNCT3_ANY, `RV32_FUNCT7_ANY}: begin /* LUI */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SRC2; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= imm_u; end {`RV32_OPCODE_AUIPC, `RV32_FUNCT3_ANY, `RV32_FUNCT7_ANY}: begin /* AUIPC */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_PC; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= imm_u; end {`RV32_OPCODE_JAL, `RV32_FUNCT3_ANY, `RV32_FUNCT7_ANY}: begin /* JAL */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SRC1P4; alu_src1_out <= `RV32_ALU_SRC1_PC; branch_op_out <= `RV32_BRANCH_OP_ALWAYS; branch_pc_src_out <= `RV32_BRANCH_PC_SRC_IMM; rd_write_out <= 1; imm_out <= imm_j; end {`RV32_OPCODE_JALR, `RV32_FUNCT3_ZERO, `RV32_FUNCT7_ANY}: begin /* JALR */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SRC1P4; alu_src1_out <= `RV32_ALU_SRC1_PC; branch_op_out <= `RV32_BRANCH_OP_ALWAYS; branch_pc_src_out <= `RV32_BRANCH_PC_SRC_REG; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_BRANCH, `RV32_FUNCT3_BRANCH_BEQ, `RV32_FUNCT7_ANY}: begin /* BEQ */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; branch_op_out <= `RV32_BRANCH_OP_ZERO; branch_pc_src_out <= `RV32_BRANCH_PC_SRC_IMM; imm_out <= imm_b; end {`RV32_OPCODE_BRANCH, `RV32_FUNCT3_BRANCH_BNE, `RV32_FUNCT7_ANY}: begin /* BNE */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; branch_op_out <= `RV32_BRANCH_OP_NON_ZERO; branch_pc_src_out <= `RV32_BRANCH_PC_SRC_IMM; imm_out <= imm_b; end {`RV32_OPCODE_BRANCH, `RV32_FUNCT3_BRANCH_BLT, `RV32_FUNCT7_ANY}: begin /* BLT */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLT; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; branch_op_out <= `RV32_BRANCH_OP_NON_ZERO; branch_pc_src_out <= `RV32_BRANCH_PC_SRC_IMM; imm_out <= imm_b; end {`RV32_OPCODE_BRANCH, `RV32_FUNCT3_BRANCH_BGE, `RV32_FUNCT7_ANY}: begin /* BGE */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLT; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; branch_op_out <= `RV32_BRANCH_OP_ZERO; branch_pc_src_out <= `RV32_BRANCH_PC_SRC_IMM; imm_out <= imm_b; end {`RV32_OPCODE_BRANCH, `RV32_FUNCT3_BRANCH_BLTU, `RV32_FUNCT7_ANY}: begin /* BLTU */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLTU; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; branch_op_out <= `RV32_BRANCH_OP_NON_ZERO; branch_pc_src_out <= `RV32_BRANCH_PC_SRC_IMM; imm_out <= imm_b; end {`RV32_OPCODE_BRANCH, `RV32_FUNCT3_BRANCH_BGEU, `RV32_FUNCT7_ANY}: begin /* BGEU */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLTU; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; branch_op_out <= `RV32_BRANCH_OP_ZERO; branch_pc_src_out <= `RV32_BRANCH_PC_SRC_IMM; imm_out <= imm_b; end {`RV32_OPCODE_LOAD, `RV32_FUNCT3_LOAD_LB, `RV32_FUNCT7_ANY}: begin /* LB */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; mem_read_out <= 1; mem_width_out <= `RV32_MEM_WIDTH_BYTE; mem_zero_extend_out <= 0; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_LOAD, `RV32_FUNCT3_LOAD_LH, `RV32_FUNCT7_ANY}: begin /* LH */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; mem_read_out <= 1; mem_width_out <= `RV32_MEM_WIDTH_HALF; mem_zero_extend_out <= 0; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_LOAD, `RV32_FUNCT3_LOAD_LW, `RV32_FUNCT7_ANY}: begin /* LW */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; mem_read_out <= 1; mem_width_out <= `RV32_MEM_WIDTH_WORD; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_LOAD, `RV32_FUNCT3_LOAD_LBU, `RV32_FUNCT7_ANY}: begin /* LBU */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; mem_read_out <= 1; mem_width_out <= `RV32_MEM_WIDTH_BYTE; mem_zero_extend_out <= 1; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_LOAD, `RV32_FUNCT3_LOAD_LHU, `RV32_FUNCT7_ANY}: begin /* LHU */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; mem_read_out <= 1; mem_width_out <= `RV32_MEM_WIDTH_HALF; mem_zero_extend_out <= 1; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_STORE, `RV32_FUNCT3_STORE_SB, `RV32_FUNCT7_ANY}: begin /* SB */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; mem_write_out <= 1; mem_width_out <= `RV32_MEM_WIDTH_BYTE; imm_out <= imm_s; end {`RV32_OPCODE_STORE, `RV32_FUNCT3_STORE_SH, `RV32_FUNCT7_ANY}: begin /* SH */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; mem_write_out <= 1; mem_width_out <= `RV32_MEM_WIDTH_HALF; imm_out <= imm_s; end {`RV32_OPCODE_STORE, `RV32_FUNCT3_STORE_SW, `RV32_FUNCT7_ANY}: begin /* SW */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; mem_write_out <= 1; mem_width_out <= `RV32_MEM_WIDTH_WORD; imm_out <= imm_s; end {`RV32_OPCODE_OP_IMM, `RV32_FUNCT3_OP_ADD_SUB, `RV32_FUNCT7_ANY}: begin /* ADDI */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_OP_IMM, `RV32_FUNCT3_OP_SLT, `RV32_FUNCT7_ANY}: begin /* SLTI */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLT; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_OP_IMM, `RV32_FUNCT3_OP_SLTU, `RV32_FUNCT7_ANY}: begin /* SLTIU */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLTU; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_OP_IMM, `RV32_FUNCT3_OP_XOR, `RV32_FUNCT7_ANY}: begin /* XORI */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_XOR; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_OP_IMM, `RV32_FUNCT3_OP_OR, `RV32_FUNCT7_ANY}: begin /* ORI */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_OR; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_OP_IMM, `RV32_FUNCT3_OP_AND, `RV32_FUNCT7_ANY}: begin /* ANDI */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_AND; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= imm_i; end {`RV32_OPCODE_OP_IMM, `RV32_FUNCT3_OP_SLL, `RV32_FUNCT7_ZERO}: begin /* SLLI */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLL; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= shamt; end {`RV32_OPCODE_OP_IMM, `RV32_FUNCT3_OP_SRL_SRA, `RV32_FUNCT7_ZERO}: begin /* SRLI */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SRL_SRA; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= shamt; end {`RV32_OPCODE_OP_IMM, `RV32_FUNCT3_OP_SRL_SRA, `RV32_FUNCT7_OP_SRA}: begin /* SRAI */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SRL_SRA; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_IMM; rd_write_out <= 1; imm_out <= shamt; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_ADD_SUB, `RV32_FUNCT7_ZERO}: begin /* ADD */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_ADD_SUB, `RV32_FUNCT7_OP_SUB}: begin /* SUB */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_ADD_SUB; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_SLL, `RV32_FUNCT7_ZERO}: begin /* SLL */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLL; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_SLT, `RV32_FUNCT7_ZERO}: begin /* SLT */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLT; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_SLTU, `RV32_FUNCT7_ZERO}: begin /* SLTU */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SLTU; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_XOR, `RV32_FUNCT7_ZERO}: begin /* XOR */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_XOR; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_SRL_SRA, `RV32_FUNCT7_ZERO}: begin /* SRL */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SRL_SRA; alu_sub_sra_out <= 0; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_SRL_SRA, `RV32_FUNCT7_OP_SRA}: begin /* SRA */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_SRL_SRA; alu_sub_sra_out <= 1; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_OR, `RV32_FUNCT7_ZERO}: begin /* OR */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_OR; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_OP, `RV32_FUNCT3_OP_AND, `RV32_FUNCT7_ZERO}: begin /* AND */ valid_out <= 1; alu_op_out <= `RV32_ALU_OP_AND; alu_src1_out <= `RV32_ALU_SRC1_REG; alu_src2_out <= `RV32_ALU_SRC2_REG; rd_write_out <= 1; end {`RV32_OPCODE_MISC_MEM, `RV32_FUNCT3_MISC_MEM_FENCE, `RV32_FUNCT7_ANY}: begin /* FENCE */ valid_out <= 1; end {`RV32_OPCODE_MISC_MEM, `RV32_FUNCT3_MISC_MEM_FENCE_I, `RV32_FUNCT7_ANY}: begin /* FENCE.I */ valid_out <= 1; end endcase if (flush_in) begin mem_read_out <= 0; mem_write_out <= 0; branch_op_out <= `RV32_BRANCH_OP_NEVER; rd_write_out <= 0; end end end endmodule `endif