STC8A I2C从机模式_STC8A8K_

#include "reg51.h" #include "intrins.h" sfr P_SW2 = 0xba; #define I2CCFG (*(unsigned char volatile xdata *)0xfe80) #define I2CMSCR (*(unsigned char volatile xdata *)0xfe81) #define I2CMSST (*(unsigned char volatile xdata *)0xfe82) #define I2CSLCR (*(unsigned char volatile xdata *)0xfe83) #define I2CSLST (*(unsigned char volatile xdata *)0xfe84) #define I2CSLADR (*(unsigned char volatile xdata *)0xfe85) #define I2CTXD (*(unsigned char volatile xdata *)0xfe86) #define I2CRXD (*(unsigned char volatile xdata *)0xfe87) sbit SDA = P1^4; sbit SCL = P1^5; bit isda; //设备地址标志 bit isma; //存储地址标志 unsigned char addr; unsigned char pdata buffer[256]; void main() { P_SW2 = 0x80; I2CCFG = 0x81; //使能I2C从机模式 I2CSLADR = 0x5a; //设置从机设备地址为5A I2CSLST = 0x00; I2CSLCR = 0x00; //禁止从机模式中断 isda = 1; //用户变量初始化 isma = 1; addr = 0; I2CTXD = buffer[addr]; while (1) { if (I2CSLST & 0x40) { I2CSLST &= ~0x40; //处理START事件 } else if (I2CSLST & 0x20) { I2CSLST &= ~0x20; //处理RECV事件 if (isda) { isda = 0; //处理RECV事件（RECV DEVICE ADDR） } else if (isma) { isma = 0; //处理RECV事件（RECV MEMORY ADDR） addr = I2CRXD; I2CTXD = buffer[addr]; } else { buffer[addr++] = I2CRXD; //处理RECV事件（RECV DATA） } } else if (I2CSLST & 0x10) { I2CSLST &= ~0x10; //处理SEND事件 if (I2CSLST & 0x02) { I2CTXD = 0xff; } else { I2CTXD = buffer[++addr]; } } else if (I2CSLST & 0x08) { I2CSLST &= ~0x08; //处理STOP事件 isda = 1; isma = 1; } } }