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ST7 S/W IMPLEMENTATION OF I2C BUS MASTER

{

if (!I2C_SR2)

/* No communication error detected

*/

{

buff*=2;

/* Shift I2C_DR to receive next bit

*/

#ifdef __HIWARE__

asm

{

nop

nop

nop

}

#else

#ifdef __CSMC__

{

_asm("nop");

_asm("nop");

_asm("nop");

}

#endif

#endif

ClrBit(PADDR,SCL);

/* Rise the SCL line

*/

do{

}while(ValBit(PADR,SCL)!=0);

/* Wait SCL at a high state

*/

if(ValBit(PADR,SDA))

buff|=1;

/* The received bit is 1

*/

else

buff|=0;

/* The received bit is 0

*/

delay(10);

SetBit(PADDR,SCL);

/* SCL at a low level

*/

}

else

r_count_err++;

}

/*--------------------------------------------------------------------------

ROUTINE NAME : I2C_Ack

INPUT/OUTPUT : None.

DESCRIPTION : Send Ack to the slave.

COMMENTS

:

--------------------------------------------------------------------------*/

void I2C_Ack(void)

{

ClrBit(PADR,SDA);

/* The master pulls the SDA line low

*/