STC micro STC8A8K64D4 Series - Example Routines; C Is Used to Access AT24 C256 in Master Mode (Interrupt Mode)

STC8A8K64D4 Series Manual
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21.5 Example Routines
21.5.1 I
2
C is Used to Access AT24C256 in Master Mode (Interrupt Mode)
C language code
//Operating frequency for test is 11.0592MHz
#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)
sfr P0M1 = 0x93;
sfr P0M0 = 0x94;
sfr P1M1 = 0x91;
sfr P1M0 = 0x92;
sfr P2M1 = 0x95;
sfr P2M0 = 0x96;
sfr P3M1 = 0xb1;
sfr P3M0 = 0xb2;
sfr P4M1 = 0xb3;
sfr P4M0 = 0xb4;
sfr P5M1 = 0xc9;
sfr P5M0 = 0xca;
sbit SDA = P1^4;
sbit SCL = P1^5;
bit busy;
void I2C_Isr() interrupt 24
{
_push_(P_SW2);
P_SW2 |= 0x80;
if (I2CMSST & 0x40)
{
I2CMSST &= ~0x40; //Clear interrupt flag
busy = 0;
}
_pop_(P_SW2);
}
void Start()
{
busy = 1;
I2CMSCR = 0x81; //Send START command
while (busy);