| `timescale 1 ns / 1 ps |
| |
| module testbench ( |
| `ifdef VERILATOR |
| input clk |
| `endif |
| ); |
| `ifndef VERILATOR |
| reg clk = 1; |
| always #5 clk = ~clk; |
| `endif |
| |
| reg resetn = 0; |
| integer resetn_cnt = 0; |
| wire trap; |
| |
| initial begin |
| // $dumpfile("testbench.vcd"); |
| // $dumpvars(0, testbench); |
| end |
| |
| always @(posedge clk) begin |
| if (resetn_cnt < 100) |
| resetn_cnt <= resetn_cnt + 1; |
| else |
| resetn <= 1; |
| end |
| |
| wire mem_valid; |
| wire mem_instr; |
| wire mem_ready; |
| wire [31:0] mem_addr; |
| wire [31:0] mem_wdata; |
| wire [3:0] mem_wstrb; |
| wire [31:0] mem_rdata; |
| |
| reg [31:0] x32 = 314159265; |
| reg [31:0] next_x32; |
| |
| always @(posedge clk) begin |
| if (resetn) begin |
| next_x32 = x32; |
| next_x32 = next_x32 ^ (next_x32 << 13); |
| next_x32 = next_x32 ^ (next_x32 >> 17); |
| next_x32 = next_x32 ^ (next_x32 << 5); |
| x32 <= next_x32; |
| end |
| end |
| |
| picorv32 #( |
| .COMPRESSED_ISA(1), |
| .ENABLE_MUL(1), |
| .ENABLE_DIV(1) |
| ) uut ( |
| .clk (clk ), |
| .resetn (resetn ), |
| .trap (trap ), |
| .mem_valid (mem_valid ), |
| .mem_instr (mem_instr ), |
| .mem_ready (mem_ready ), |
| .mem_addr (mem_addr ), |
| .mem_wdata (mem_wdata ), |
| .mem_wstrb (mem_wstrb ), |
| .mem_rdata (mem_rdata ) |
| ); |
| |
| reg [7:0] memory [0:4*1024*1024-1]; |
| initial $readmemh("test.hex", memory); |
| |
| assign mem_ready = x32[0] && mem_valid; |
| |
| assign mem_rdata[ 7: 0] = memory[mem_addr + 0]; |
| assign mem_rdata[15: 8] = memory[mem_addr + 1]; |
| assign mem_rdata[23:16] = memory[mem_addr + 2]; |
| assign mem_rdata[31:24] = memory[mem_addr + 3]; |
| |
| always @(posedge clk) begin |
| if (mem_valid && mem_ready) begin |
| if (mem_wstrb && mem_addr == 'h10000000) begin |
| $write("%c", mem_wdata[ 7: 0]); |
| `ifndef VERILATOR |
| $fflush; |
| `endif |
| end else begin |
| if (mem_wstrb[0]) memory[mem_addr + 0] <= mem_wdata[ 7: 0]; |
| if (mem_wstrb[1]) memory[mem_addr + 1] <= mem_wdata[15: 8]; |
| if (mem_wstrb[2]) memory[mem_addr + 2] <= mem_wdata[23:16]; |
| if (mem_wstrb[3]) memory[mem_addr + 3] <= mem_wdata[31:24]; |
| end |
| end |
| end |
| |
| always @(posedge clk) begin |
| if (resetn && trap) begin |
| // repeat (10) @(posedge clk); |
| // $display("TRAP"); |
| $finish; |
| end |
| end |
| endmodule |