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Add ALU control signals to the decoder

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This commit is contained in:
Graham Edgecombe 2017-12-01 22:54:08 +00:00
parent 4aa64f864a
commit 37d703c83e
3 changed files with 149 additions and 17 deletions
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16
rv32_alu.sv
View file

@ -1,18 +1,4 @@
localparam RV32_ALU_OP_ADD_SUB = 4'b0000;
localparam RV32_ALU_OP_XOR = 4'b0001;
localparam RV32_ALU_OP_OR = 4'b0010;
localparam RV32_ALU_OP_AND = 4'b0011;
localparam RV32_ALU_OP_SLL = 4'b0100;
localparam RV32_ALU_OP_SRL_SRA = 4'b0101;
localparam RV32_ALU_OP_SLT = 4'b0110;
localparam RV32_ALU_OP_SLTU = 4'b0111;
localparam RV32_ALU_OP_SRC2 = 4'b1000;
localparam RV32_ALU_SRC1_REG = 1'b0;
localparam RV32_ALU_SRC1_PC = 1'b1;
localparam RV32_ALU_SRC2_REG = 1'b0;
localparam RV32_ALU_SRC2_IMM = 1'b1;
`include "rv32_alu_ops.sv"
module rv32_alu (
input clk,

15
rv32_alu_ops.sv Normal file
View file

@ -0,0 +1,15 @@
localparam RV32_ALU_OP_ADD_SUB = 4'b0000;
localparam RV32_ALU_OP_XOR = 4'b0001;
localparam RV32_ALU_OP_OR = 4'b0010;
localparam RV32_ALU_OP_AND = 4'b0011;
localparam RV32_ALU_OP_SLL = 4'b0100;
localparam RV32_ALU_OP_SRL_SRA = 4'b0101;
localparam RV32_ALU_OP_SLT = 4'b0110;
localparam RV32_ALU_OP_SLTU = 4'b0111;
localparam RV32_ALU_OP_SRC2 = 4'b1000;
localparam RV32_ALU_SRC1_REG = 1'b0;
localparam RV32_ALU_SRC1_PC = 1'b1;
localparam RV32_ALU_SRC2_REG = 1'b0;
localparam RV32_ALU_SRC2_IMM = 1'b1;

135
rv32_decode.sv
View file

@ -1,3 +1,4 @@
`include "rv32_alu_ops.sv"
`include "rv32_opcodes.sv"
`include "rv32_regs.sv"
@ -64,11 +65,17 @@ module rv32_decode (
{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;
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;
imm_out <= imm_u;
end
{RV32_OPCODE_JAL, RV32_FUNCT3_ANY, RV32_FUNCT7_ANY}: begin
@ -84,157 +91,281 @@ module rv32_decode (
{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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
imm_out <= imm_s;
end
{RV32_OPCODE_STORE, RV32_FUNCT3_STORE_SH, RV32_FUNCT7_ANY}: begin
/* SH */
valid_out <= 1;
imm_out <= imm_s;
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;
imm_out <= imm_s;
end
{RV32_OPCODE_STORE, RV32_FUNCT3_STORE_SW, RV32_FUNCT7_ANY}: begin
/* SW */
valid_out <= 1;
imm_out <= imm_s;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
end
endcase
end