用DDS生成正弦波的数据用modelsim导出怎样能使他是有符号数? 这样为什么不行谢谢 以下是测试文件导出数据的部分 initial begin signal_in1=$fopen("data_out1.txt"); signal_in2=$fopen("data_out2.txt"); signal_in3=$fopen("data_out3.txt"); signal_out=$fopen("data_out.txt"); end always @(negedge clk) begin $fwrite(signal_in1,"%d\n",data_out1); $fwrite(signal_in2,"%d\n",data_out2); $fwrite(signal_in3,"%d\n",data_out3); $fwrite(signal_out,"%d\n",data_out); end