#include "reg52.h" #include"intrins.h" //_nop_();延时函数用 #define uchar unsigned char #define uint unsigned int sbit SPI_CLK = P3^7; //时钟 sbit SPI_DATA = P3^5; //数据输出 sbit CS_DA = P3^4; //片选 sbit k1=P2^7; sbit k2=P2^6; sbit k3=P2^5; //判断是否有键按下 float vout;//系统输出电压 uint shuzi;//给da数字量