10/16

ST7 S/W IMPLEMENTATION OF I2C BUS MASTER

INPUT/OUTPUT : None.

DESCRIPTION : Generates I2C-Bus Stop Condition.

COMMENTS

:

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

void I2Cm_Stop (void)

{

SetBit(PADDR,SDA);

/* Configure SDA and SCL as output open drain to have a low state

*/

SetBit(PADDR,SCL);

ClrBit(PADDR,SCL);

/* Configure SCL as floating input to have a high state

*/

delay(4);

/* Macro delay with time=4 (4.875 µs)

*/

ClrBit(PADDR,SDA);

/* Configure SDA as floating input to have a high state

*/

/* Delay after the Stop did in main.c with Wait_1ms()

*/

}

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

ROUTINE NAME : wait_Ack

INPUT/OUTPUT : None.

DESCRIPTION : Acknowledge received?

COMMENTS

: Transfer sequence = DATA, ACK.

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

void wait_Ack (void)

{

SetBit(PADDR,SCL);

/* Output open drain to have a low level */

ClrBit(PADDR,SDA);

/* Floating input, the slave has to pull SDA low */

delay(1);

if (ValBit(PADR,SDA))

/* Test of SDA level, if high -> pb

*/

{

SetBit(I2C_SR2,AF);

ClrBit(I2C_SR1,ACK);

return;

}

delay(2);

if (ValBit(PADR,SDA))

/* Test of SDA level, if high -> pb

*/

{

SetBit(I2C_SR2,AF);

ClrBit(I2C_SR1,ACK);

return;

}

delay(5);

ClrBit(PADDR,SCL);

/* Start of the generation of 1 clock pulse */

delay(1);

if (ValBit(PADR,SDA))

/* Test of SDA level, if high -> pb

*/

{