mirror of https://github.com/YosysHQ/yosys.git
Add test cases for co-simulation
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@ -1,2 +1,4 @@
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*.log
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run-test.mk
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*.vcd
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*.fst
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@ -0,0 +1,79 @@
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module alu(
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input clk,
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input [7:0] A,
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input [7:0] B,
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input [3:0] operation,
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output reg [7:0] result,
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output reg CF,
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output reg ZF,
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output reg SF
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);
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localparam ALU_OP_ADD /* verilator public_flat */ = 4'b0000;
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localparam ALU_OP_SUB /* verilator public_flat */ = 4'b0001;
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localparam ALU_OP_ADC /* verilator public_flat */ = 4'b0010;
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localparam ALU_OP_SBC /* verilator public_flat */ = 4'b0011;
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localparam ALU_OP_AND /* verilator public_flat */ = 4'b0100;
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localparam ALU_OP_OR /* verilator public_flat */ = 4'b0101;
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localparam ALU_OP_NOT /* verilator public_flat */ = 4'b0110;
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localparam ALU_OP_XOR /* verilator public_flat */ = 4'b0111;
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localparam ALU_OP_SHL /* verilator public_flat */ = 4'b1000;
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localparam ALU_OP_SHR /* verilator public_flat */ = 4'b1001;
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localparam ALU_OP_SAL /* verilator public_flat */ = 4'b1010;
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localparam ALU_OP_SAR /* verilator public_flat */ = 4'b1011;
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localparam ALU_OP_ROL /* verilator public_flat */ = 4'b1100;
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localparam ALU_OP_ROR /* verilator public_flat */ = 4'b1101;
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localparam ALU_OP_RCL /* verilator public_flat */ = 4'b1110;
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localparam ALU_OP_RCR /* verilator public_flat */ = 4'b1111;
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reg [8:0] tmp;
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always @(posedge clk)
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begin
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case (operation)
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ALU_OP_ADD :
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tmp = A + B;
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ALU_OP_SUB :
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tmp = A - B;
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ALU_OP_ADC :
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tmp = A + B + { 7'b0000000, CF };
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ALU_OP_SBC :
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tmp = A - B - { 7'b0000000, CF };
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ALU_OP_AND :
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tmp = {1'b0, A & B };
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ALU_OP_OR :
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tmp = {1'b0, A | B };
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ALU_OP_NOT :
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tmp = {1'b0, ~B };
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ALU_OP_XOR :
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tmp = {1'b0, A ^ B};
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ALU_OP_SHL :
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tmp = { A[7], A[6:0], 1'b0};
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ALU_OP_SHR :
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tmp = { A[0], 1'b0, A[7:1]};
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ALU_OP_SAL :
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// Same as SHL
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tmp = { A[7], A[6:0], 1'b0};
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ALU_OP_SAR :
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tmp = { A[0], A[7], A[7:1]};
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ALU_OP_ROL :
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tmp = { A[7], A[6:0], A[7]};
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ALU_OP_ROR :
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tmp = { A[0], A[0], A[7:1]};
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ALU_OP_RCL :
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tmp = { A[7], A[6:0], CF};
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ALU_OP_RCR :
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tmp = { A[0], CF, A[7:1]};
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endcase
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CF <= tmp[8];
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ZF <= tmp[7:0] == 0;
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SF <= tmp[7];
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result <= tmp[7:0];
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end
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endmodule
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@ -0,0 +1,9 @@
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read_verilog grom_computer.v grom_cpu.v alu.v ram_memory.v;
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prep -top grom_computer;
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sim -clock clk -reset reset -fst grom.fst -vcd grom.vcd -a -n 80
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sim -clock clk -r grom.fst -scope grom_computer -start 25ns -stop 100ns -sim-cmp
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sim -clock clk -r grom.fst -scope grom_computer -stop 100ns -sim-gold
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sim -clock clk -r grom.fst -scope grom_computer -n 10 -sim-gate -a
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@ -0,0 +1,31 @@
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module grom_computer
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(input clk, // Main Clock
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input reset, // reset
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output hlt,
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output reg[7:0] display_out
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);
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wire [11:0] addr;
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wire [7:0] memory_out;
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wire [7:0] memory_in;
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wire mem_enable;
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wire we;
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wire ioreq;
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grom_cpu cpu(.clk(clk),.reset(reset),.addr(addr),.data_in(memory_out),.data_out(memory_in),.we(we),.ioreq(ioreq),.hlt(hlt));
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assign mem_enable = we & ~ioreq;
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ram_memory memory(.clk(clk),.addr(addr),.data_in(memory_in),.we(mem_enable),.data_out(memory_out));
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always @(posedge clk)
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begin
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if(ioreq==1 && we==1)
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begin
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display_out <= memory_in;
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`ifdef DISASSEMBLY
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$display("Display output : %h", memory_in);
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`endif
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end
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end
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endmodule
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@ -0,0 +1,747 @@
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module grom_cpu(
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input clk,
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input reset,
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output reg [11:0] addr,
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input [7:0] data_in,
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output reg [7:0] data_out,
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output reg we,
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output reg ioreq,
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output reg hlt
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);
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reg[11:0] PC /* verilator public_flat */; // Program counter
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reg[7:0] IR /* verilator public_flat */; // Instruction register
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reg[7:0] VALUE /* verilator public_flat */; // Temp reg for storing 2nd operand
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reg[3:0] CS /* verilator public_flat */; // Code segment regiser
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reg[3:0] DS /* verilator public_flat */; // Data segment regiser
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reg[11:0] SP /* verilator public_flat */; // Stack pointer regiser
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reg[7:0] R[0:3] /* verilator public_flat */; // General purpose registers
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reg[11:0] FUTURE_PC /* verilator public_flat */; // PC to jump to
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localparam STATE_RESET /*verilator public_flat*/ = 5'b00000;
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localparam STATE_FETCH_PREP /*verilator public_flat*/ = 5'b00001;
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localparam STATE_FETCH_WAIT /*verilator public_flat*/ = 5'b00010;
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localparam STATE_FETCH /*verilator public_flat*/ = 5'b00011;
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localparam STATE_EXECUTE /*verilator public_flat*/ = 5'b00100;
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localparam STATE_FETCH_VALUE_PREP /*verilator public_flat*/ = 5'b00101;
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localparam STATE_FETCH_VALUE /*verilator public_flat*/ = 5'b00110;
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localparam STATE_EXECUTE_DBL /*verilator public_flat*/ = 5'b00111;
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localparam STATE_LOAD_VALUE /*verilator public_flat*/ = 5'b01000;
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localparam STATE_LOAD_VALUE_WAIT /*verilator public_flat*/ = 5'b01001;
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localparam STATE_ALU_RESULT_WAIT /*verilator public_flat*/ = 5'b01010;
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localparam STATE_ALU_RESULT /*verilator public_flat*/ = 5'b01011;
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localparam STATE_PUSH_PC_LOW /*verilator public_flat*/ = 5'b01100;
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localparam STATE_JUMP /*verilator public_flat*/ = 5'b01101;
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localparam STATE_RET_VALUE_WAIT /*verilator public_flat*/ = 5'b01110;
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localparam STATE_RET_VALUE /*verilator public_flat*/ = 5'b01111;
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localparam STATE_RET_VALUE_WAIT2 /*verilator public_flat*/ = 5'b10000;
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localparam STATE_RET_VALUE2 /*verilator public_flat*/ = 5'b10001;
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reg [4:0] state /* verilator public_flat */ = STATE_RESET;
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reg [7:0] alu_a /* verilator public_flat */;
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reg [7:0] alu_b /* verilator public_flat */;
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reg [3:0] alu_op /* verilator public_flat */;
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reg [1:0] RESULT_REG /* verilator public_flat */;
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wire [7:0] alu_res /* verilator public_flat */;
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wire alu_CF /* verilator public_flat */;
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wire alu_ZF /* verilator public_flat */;
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wire alu_SF /* verilator public_flat */;
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reg jump;
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alu alu(.clk(clk),.A(alu_a),.B(alu_b),.operation(alu_op),.result(alu_res),.CF(alu_CF),.ZF(alu_ZF),.SF(alu_SF));
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always @(posedge clk)
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begin
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if (reset)
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begin
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state <= STATE_RESET;
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hlt <= 0;
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end
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else
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begin
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case (state)
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STATE_RESET :
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begin
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PC <= 12'h000;
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state <= STATE_FETCH_PREP;
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CS <= 4'h0;
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DS <= 4'h0;
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R[0] <= 8'h00;
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R[1] <= 8'h00;
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R[2] <= 8'h00;
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R[3] <= 8'h00;
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SP <= 12'hfff;
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end
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STATE_FETCH_PREP :
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begin
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addr <= PC;
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we <= 0;
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ioreq <= 0;
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state <= STATE_FETCH_WAIT;
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end
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STATE_FETCH_WAIT :
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begin
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// Sync with memory due to CLK
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state <= (hlt) ? STATE_FETCH_PREP : STATE_FETCH;
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end
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STATE_FETCH :
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begin
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IR <= data_in;
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PC <= PC + 1;
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state <= STATE_EXECUTE;
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end
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STATE_EXECUTE :
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begin
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`ifdef DISASSEMBLY
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$display(" PC %h R0 %h R1 %h R2 %h R3 %h CS %h DS %h SP %h ALU [%d %d %d]", PC, R[0], R[1], R[2], R[3], CS, DS, SP, alu_CF,alu_SF,alu_ZF);
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`endif
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if (IR[7])
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begin
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addr <= PC;
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state <= STATE_FETCH_VALUE_PREP;
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PC <= PC + 1;
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end
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else
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begin
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case(IR[6:4])
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3'b000 :
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begin
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`ifdef DISASSEMBLY
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$display("MOV R%d,R%d",IR[3:2],IR[1:0]);
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`endif
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R[IR[3:2]] <= R[IR[1:0]];
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state <= STATE_FETCH_PREP;
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end
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3'b001 :
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begin
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alu_a <= R[0]; // first input R0
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alu_b <= R[IR[1:0]];
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RESULT_REG <= 0; // result in R0
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alu_op <= { 2'b00, IR[3:2] };
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state <= STATE_ALU_RESULT_WAIT;
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`ifdef DISASSEMBLY
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case(IR[3:2])
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2'b00 : begin
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$display("ADD R%d",IR[1:0]);
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end
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2'b01 : begin
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$display("SUB R%d",IR[1:0]);
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end
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2'b10 : begin
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$display("ADC R%d",IR[1:0]);
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end
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2'b11 : begin
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$display("SBC R%d",IR[1:0]);
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end
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endcase
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`endif
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end
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3'b010 :
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begin
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alu_a <= R[0]; // first input R0
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alu_b <= R[IR[1:0]];
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RESULT_REG <= 0; // result in R0
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alu_op <= { 2'b01, IR[3:2] };
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state <= STATE_ALU_RESULT_WAIT;
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`ifdef DISASSEMBLY
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case(IR[3:2])
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2'b00 : begin
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$display("AND R%d",IR[1:0]);
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end
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2'b01 : begin
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$display("OR R%d",IR[1:0]);
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end
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2'b10 : begin
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$display("NOT R%d",IR[1:0]);
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end
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2'b11 : begin
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$display("XOR R%d",IR[1:0]);
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end
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endcase
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`endif
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end
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3'b011 :
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begin
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RESULT_REG <= IR[1:0]; // result in REG
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// CMP and TEST are not storing result
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state <= IR[3] ? STATE_FETCH_PREP : STATE_ALU_RESULT_WAIT;
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// CMP and TEST are having first input R0, for INC and DEC is REG
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alu_a <= IR[3] ? R[0] : R[IR[1:0]];
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// CMP and TEST are having second input REG, for INC and DEC is 1
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alu_b <= IR[3] ? R[IR[1:0]] : 8'b00000001;
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case(IR[3:2])
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2'b00 : begin
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`ifdef DISASSEMBLY
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$display("INC R%d",IR[1:0]);
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`endif
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alu_op <= 4'b0001; // ALU_OP_ADD
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end
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2'b01 : begin
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`ifdef DISASSEMBLY
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$display("DEC R%d",IR[1:0]);
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`endif
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alu_op <= 4'b0001; // ALU_OP_SUB
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end
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2'b10 : begin
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`ifdef DISASSEMBLY
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$display("CMP R%d",IR[1:0]);
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`endif
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alu_op <= 4'b0001; // ALU_OP_SUB
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end
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2'b11 : begin
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`ifdef DISASSEMBLY
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$display("TST R%d",IR[1:0]);
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`endif
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alu_op <= 4'b0100; // ALU_OP_AND
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end
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endcase
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end
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3'b100 :
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begin
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if (IR[3]==0)
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begin
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alu_a <= R[0]; // first input R0
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// no 2nd input
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RESULT_REG <= 0; // result in R0
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alu_op <= { 1'b1, IR[2:0] };
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`ifdef DISASSEMBLY
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case(IR[2:0])
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3'b000 : begin
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$display("SHL");
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end
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3'b001 : begin
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$display("SHR");
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end
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3'b010 : begin
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$display("SAL");
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end
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3'b011 : begin
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$display("SAR");
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end
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3'b100 : begin
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$display("ROL");
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end
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3'b101 : begin
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$display("ROR");
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end
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3'b110 : begin
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$display("RCL");
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end
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3'b111 : begin
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$display("RCR");
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end
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endcase
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`endif
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state <= STATE_ALU_RESULT_WAIT;
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end
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else
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begin
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if (IR[2]==0)
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begin
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`ifdef DISASSEMBLY
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$display("PUSH R%d",IR[1:0]);
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`endif
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addr <= SP;
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we <= 1;
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ioreq <= 0;
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data_out <= R[IR[1:0]];
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SP <= SP - 1;
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state <= STATE_FETCH_PREP;
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end
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else
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begin
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`ifdef DISASSEMBLY
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$display("POP R%d",IR[1:0]);
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`endif
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addr <= SP + 1;
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we <= 0;
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ioreq <= 0;
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RESULT_REG <= IR[1:0];
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SP <= SP + 1;
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state <= STATE_LOAD_VALUE_WAIT;
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end
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end
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end
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3'b101 :
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begin
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`ifdef DISASSEMBLY
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$display("LOAD R%d,[R%d]", IR[3:2], IR[1:0]);
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`endif
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addr <= { DS, R[IR[1:0]] };
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we <= 0;
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ioreq <= 0;
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RESULT_REG <= IR[3:2];
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state <= STATE_LOAD_VALUE_WAIT;
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end
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3'b110 :
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begin
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`ifdef DISASSEMBLY
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$display("STORE [R%d],R%d", IR[3:2], IR[1:0]);
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`endif
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addr <= { DS, R[IR[3:2]] };
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we <= 1;
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ioreq <= 0;
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data_out <= R[IR[1:0]];
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state <= STATE_FETCH_PREP;
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end
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3'b111 :
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begin
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// Special instuctions
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case(IR[3:2])
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2'b00 : begin
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CS <= R[IR[1:0]][3:0];
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state <= STATE_FETCH_PREP;
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`ifdef DISASSEMBLY
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$display("MOV CS,R%d",IR[1:0]);
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`endif
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end
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2'b01 : begin
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DS <= R[IR[1:0]][3:0];
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state <= STATE_FETCH_PREP;
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`ifdef DISASSEMBLY
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$display("MOV DS,R%d",IR[1:0]);
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`endif
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end
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2'b10 : begin
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case(IR[1:0])
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2'b00 : begin
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`ifdef DISASSEMBLY
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$display("PUSH CS");
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`endif
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addr <= SP;
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we <= 1;
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ioreq <= 0;
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data_out <= { 4'b0000, CS};
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SP <= SP - 1;
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state <= STATE_FETCH_PREP;
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end
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2'b01 : begin
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`ifdef DISASSEMBLY
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$display("PUSH DS");
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`endif
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addr <= SP;
|
||||
we <= 1;
|
||||
ioreq <= 0;
|
||||
data_out <= { 4'b0000, DS};
|
||||
SP <= SP - 1;
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
2'b10 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Unused opcode");
|
||||
`endif
|
||||
end
|
||||
2'b11 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Unused opcode");
|
||||
`endif
|
||||
end
|
||||
endcase
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
2'b11 : begin
|
||||
case(IR[1:0])
|
||||
2'b00 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Unused opcode");
|
||||
`endif
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
2'b01 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Unused opcode");
|
||||
`endif
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
2'b10 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("RET");
|
||||
`endif
|
||||
addr <= SP + 1;
|
||||
we <= 0;
|
||||
ioreq <= 0;
|
||||
SP <= SP + 1;
|
||||
state <= STATE_RET_VALUE_WAIT;
|
||||
end
|
||||
2'b11 : begin
|
||||
hlt <= 1;
|
||||
`ifdef DISASSEMBLY
|
||||
$display("HALT");
|
||||
`endif
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
endcase
|
||||
end
|
||||
endcase
|
||||
end
|
||||
endcase
|
||||
end
|
||||
end
|
||||
STATE_FETCH_VALUE_PREP :
|
||||
begin
|
||||
// Sync with memory due to CLK
|
||||
state <= STATE_FETCH_VALUE;
|
||||
end
|
||||
STATE_FETCH_VALUE :
|
||||
begin
|
||||
VALUE <= data_in;
|
||||
state <= STATE_EXECUTE_DBL;
|
||||
end
|
||||
STATE_EXECUTE_DBL :
|
||||
begin
|
||||
case(IR[6:4])
|
||||
3'b000 :
|
||||
begin
|
||||
if (IR[3]==0)
|
||||
begin
|
||||
case(IR[2:0])
|
||||
3'b000 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JMP %h ",{ CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = 1;
|
||||
end
|
||||
3'b001 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JC %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_CF==1);
|
||||
end
|
||||
3'b010 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JNC %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_CF==0);
|
||||
end
|
||||
3'b011 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JM %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_SF==1);
|
||||
end
|
||||
3'b100 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JP %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_SF==0);
|
||||
end
|
||||
3'b101 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JZ %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_ZF==1);
|
||||
end
|
||||
3'b110 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JNZ %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_ZF==0);
|
||||
end
|
||||
3'b111 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Unused opcode %h",IR);
|
||||
`endif
|
||||
jump = 0;
|
||||
end
|
||||
endcase
|
||||
|
||||
if (jump)
|
||||
begin
|
||||
PC <= { CS, VALUE[7:0] };
|
||||
addr <= { CS, VALUE[7:0] };
|
||||
we <= 0;
|
||||
ioreq <= 0;
|
||||
end
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
else
|
||||
begin
|
||||
case(IR[2:0])
|
||||
3'b000 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JR %h ", PC + {VALUE[7],VALUE[7],VALUE[7],VALUE[7],VALUE[7:0]} );
|
||||
`endif
|
||||
jump = 1;
|
||||
end
|
||||
3'b001 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JRC %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_CF==1);
|
||||
end
|
||||
3'b010 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JRNC %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_CF==0);
|
||||
end
|
||||
3'b011 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JRM %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_SF==1);
|
||||
end
|
||||
3'b100 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JRP %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_SF==0);
|
||||
end
|
||||
3'b101 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JRZ %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_ZF==1);
|
||||
end
|
||||
3'b110 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JRNZ %h ",{CS, VALUE[7:0] });
|
||||
`endif
|
||||
jump = (alu_ZF==0);
|
||||
end
|
||||
3'b111 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Unused opcode %h",IR);
|
||||
`endif
|
||||
jump = 0;
|
||||
end
|
||||
endcase
|
||||
if (jump)
|
||||
begin
|
||||
PC <= PC + {VALUE[7],VALUE[7],VALUE[7],VALUE[7],VALUE[7:0]};
|
||||
addr <= PC + {VALUE[7],VALUE[7],VALUE[7],VALUE[7],VALUE[7:0]};
|
||||
we <= 0;
|
||||
ioreq <= 0;
|
||||
end
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
end
|
||||
3'b001 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("JUMP %h ",{ IR[3:0], VALUE[7:0] });
|
||||
`endif
|
||||
PC <= { IR[3:0], VALUE[7:0] };
|
||||
addr <= { IR[3:0], VALUE[7:0] };
|
||||
we <= 0;
|
||||
ioreq <= 0;
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
3'b010 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("CALL %h ",{ IR[3:0], VALUE[7:0] });
|
||||
`endif
|
||||
FUTURE_PC <= { IR[3:0], VALUE[7:0] };
|
||||
addr <= SP;
|
||||
we <= 1;
|
||||
ioreq <= 0;
|
||||
data_out <= { 4'b0000, PC[11:8]};
|
||||
SP <= SP - 1;
|
||||
state <= STATE_PUSH_PC_LOW;
|
||||
end
|
||||
3'b011 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("MOV SP,%h ",{ IR[3:0], VALUE[7:0] });
|
||||
`endif
|
||||
SP <= { IR[3:0], VALUE[7:0] };
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
3'b100 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("IN R%d,[0x%h]",IR[1:0], VALUE);
|
||||
`endif
|
||||
ioreq <= 1;
|
||||
we <= 0;
|
||||
addr <= { 4'b0000, VALUE };
|
||||
RESULT_REG <= IR[1:0];
|
||||
state <= STATE_LOAD_VALUE_WAIT;
|
||||
end
|
||||
3'b101 :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("OUT [0x%h],R%d",VALUE,IR[1:0]);
|
||||
`endif
|
||||
ioreq <= 1;
|
||||
we <= 1;
|
||||
addr <= { 4'b0000, VALUE };
|
||||
data_out <= R[IR[1:0]];
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
3'b110 :
|
||||
begin
|
||||
// Special instuctions
|
||||
case(IR[1:0])
|
||||
2'b00 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("MOV CS,0x%h",VALUE);
|
||||
`endif
|
||||
CS <= VALUE[3:0];
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
2'b01 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("MOV DS,0x%h",VALUE);
|
||||
`endif
|
||||
DS <= VALUE[3:0];
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
2'b10 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Unused opcode %h",IR);
|
||||
`endif
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
2'b11 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Unused opcode %h",IR);
|
||||
`endif
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
endcase
|
||||
end
|
||||
3'b111 :
|
||||
begin
|
||||
case(IR[3:2])
|
||||
2'b00 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("MOV R%d,0x%h",IR[1:0],VALUE);
|
||||
`endif
|
||||
R[IR[1:0]] <= VALUE;
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
2'b01 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("LOAD R%d,[0x%h]",IR[1:0], {DS, VALUE});
|
||||
`endif
|
||||
addr <= { DS, VALUE };
|
||||
we <= 0;
|
||||
ioreq <= 0;
|
||||
RESULT_REG <= IR[1:0];
|
||||
|
||||
state <= STATE_LOAD_VALUE_WAIT;
|
||||
end
|
||||
2'b10 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("STORE [0x%h],R%d", {DS, VALUE}, IR[1:0]);
|
||||
`endif
|
||||
addr <= { DS, VALUE };
|
||||
we <= 1;
|
||||
ioreq <= 0;
|
||||
data_out <= R[IR[1:0]];
|
||||
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
2'b11 : begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Unused opcode %h",IR);
|
||||
`endif
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
endcase
|
||||
end
|
||||
endcase
|
||||
end
|
||||
STATE_LOAD_VALUE_WAIT :
|
||||
begin
|
||||
// Sync with memory due to CLK
|
||||
state <= STATE_LOAD_VALUE;
|
||||
end
|
||||
STATE_LOAD_VALUE :
|
||||
begin
|
||||
R[RESULT_REG] <= data_in;
|
||||
we <= 0;
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
STATE_ALU_RESULT_WAIT :
|
||||
begin
|
||||
state <= STATE_ALU_RESULT;
|
||||
end
|
||||
STATE_ALU_RESULT :
|
||||
begin
|
||||
R[RESULT_REG] <= alu_res;
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
STATE_PUSH_PC_LOW :
|
||||
begin
|
||||
addr <= SP;
|
||||
we <= 1;
|
||||
ioreq <= 0;
|
||||
data_out <= PC[7:0];
|
||||
SP <= SP - 1;
|
||||
state <= STATE_JUMP;
|
||||
end
|
||||
STATE_JUMP :
|
||||
begin
|
||||
`ifdef DISASSEMBLY
|
||||
$display("Jumping to %h",FUTURE_PC);
|
||||
`endif
|
||||
PC <= FUTURE_PC;
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
STATE_RET_VALUE_WAIT :
|
||||
begin
|
||||
// Sync with memory due to CLK
|
||||
state <= STATE_RET_VALUE;
|
||||
end
|
||||
STATE_RET_VALUE :
|
||||
begin
|
||||
FUTURE_PC <= { 4'b0000, data_in };
|
||||
we <= 0;
|
||||
state <= STATE_RET_VALUE_WAIT2;
|
||||
|
||||
addr <= SP + 1;
|
||||
we <= 0;
|
||||
ioreq <= 0;
|
||||
SP <= SP + 1;
|
||||
end
|
||||
STATE_RET_VALUE_WAIT2 :
|
||||
begin
|
||||
// Sync with memory due to CLK
|
||||
state <= STATE_RET_VALUE2;
|
||||
end
|
||||
STATE_RET_VALUE2 :
|
||||
begin
|
||||
FUTURE_PC <= FUTURE_PC | ({ 4'b0000, data_in } << 8);
|
||||
we <= 0;
|
||||
state <= STATE_JUMP;
|
||||
end
|
||||
default :
|
||||
begin
|
||||
state <= STATE_FETCH_PREP;
|
||||
end
|
||||
endcase
|
||||
end
|
||||
end
|
||||
endmodule
|
|
@ -0,0 +1,37 @@
|
|||
module ram_memory(
|
||||
input clk,
|
||||
input [11:0] addr,
|
||||
input [7:0] data_in,
|
||||
input we,
|
||||
output reg [7:0] data_out
|
||||
);
|
||||
|
||||
reg [7:0] store[0:4095] /* verilator public_flat */;
|
||||
|
||||
initial
|
||||
begin
|
||||
store[0] <= 8'b11100001; // MOV DS,2
|
||||
store[1] <= 8'b00000010; //
|
||||
store[2] <= 8'b01010100; // LOAD R1,[R0]
|
||||
store[3] <= 8'b00110001; // INC R1
|
||||
store[4] <= 8'b00110001; // INC R1
|
||||
store[5] <= 8'b01100001; // STORE [R0],R1
|
||||
store[6] <= 8'b11010001; // OUT [0],R1
|
||||
store[7] <= 8'b00000000; //
|
||||
store[8] <= 8'b00110001; // INC R1
|
||||
store[9] <= 8'b10100001; // CALL 0x100
|
||||
store[10] <= 8'b00000000; //
|
||||
store[11] <= 8'b01111111; // HLT
|
||||
|
||||
|
||||
store[256] <= 8'b11010001; // OUT [0],R1
|
||||
store[257] <= 8'b00000000; //
|
||||
store[258] <= 8'b01111110; // RET
|
||||
end
|
||||
|
||||
always @(posedge clk)
|
||||
if (we)
|
||||
store[addr] <= data_in;
|
||||
else
|
||||
data_out <= store[addr];
|
||||
endmodule
|
|
@ -0,0 +1,48 @@
|
|||
# Create stimulus file
|
||||
read_verilog <<EOT
|
||||
module top (clk, reset, cnt);
|
||||
|
||||
input clk;
|
||||
input reset;
|
||||
output [7:0] cnt;
|
||||
|
||||
reg [7:0] cnt;
|
||||
|
||||
endmodule
|
||||
EOT
|
||||
prep -top top;
|
||||
sim -clock clk -reset reset -fst stimulus.fst -n 10
|
||||
design -reset
|
||||
|
||||
# Counter implementation
|
||||
read_verilog <<EOT
|
||||
module top (clk, reset, cnt);
|
||||
|
||||
input clk;
|
||||
input reset;
|
||||
output [7:0] cnt;
|
||||
|
||||
reg [7:0] cnt;
|
||||
|
||||
always @(posedge clk)
|
||||
if (!reset)
|
||||
cnt = cnt + 1;
|
||||
else
|
||||
cnt = 0;
|
||||
|
||||
endmodule
|
||||
EOT
|
||||
prep -top top;
|
||||
|
||||
# Simulate with stimulus
|
||||
sim -clock clk -scope top -r stimulus.fst
|
||||
|
||||
# Stimulus does not have counter values
|
||||
# x in FST can match any value in simulation
|
||||
sim -clock clk -scope top -r stimulus.fst -sim-gate
|
||||
|
||||
# Stimulus does not have counter values
|
||||
# x in simulation can match any value in FST
|
||||
# so we expect error
|
||||
logger -expect error "Signal difference" 1
|
||||
sim -clock clk -scope top -r stimulus.fst -sim-gold
|
Loading…
Reference in New Issue