verilog 通过DPI-C调用C 流水灯模拟

verilog 通过DPI-C调用C简单示例， verillator模拟

ledloop.v

module ledloop(input wire clk,output wire[3:0] LED
);reg[31:0] cnt = 32'h00000000;always @(posedge clk)cnt <= cnt + 1;assign LED = 4'b0001 << cnt[21:20];
endmodule

电脑模拟较慢，2M计数位移一次，可以自行通过计数位调整。

转接
led_adaptor.v

module led_adaptor(input wire clk,input wire[3:0] LED
);
import "DPI-C"  function void  print(int a); 
reg[3:0] state ;always @(posedge clk)if (state != LED) beginprint(int'(LED));state <= LED;endendmodule

tb
top.v

module top;
wire[3:0] led;
reg clk = 1'b0;initial beginforever #1  clk = ~clk;
endledloop  loop1(.clk(clk),.LED(led));led_adaptor  adaptor1(.clk(clk),.LED(led));endmodule

print.c

#define BITWIDTH 4
#include <stdio.h>
#include <unistd.h>
#include "svdpi.h"
extern "C"
void print(int a) {unsigned  b = (unsigned)a;printf("\r");  //移至行首printf("\033[K");  //清除光标后字符for (int i = 0; i < BITWIDTH; i++){if (b&1)printf("* ");elseprintf("  ");b = b >> 1;}   fflush(stdout);
}

Makefile

.PHONY:cleanVERILATOR = verilatorOUTDIR=out
VERILATOR_FLAGS =  -Wall -top top -Mdir $(OUTDIR) -cc -binary -build -j 2default: runrun: print.c top.v  ledloop.v led_adaptor.v$(VERILATOR) $(VERILATOR_FLAGS) $^./$(OUTDIR)/Vtopclean:-rm -rf $(OUTDIR)