ADSP-21489 I2C and RTC DS1388

Hi,

Trying to use ADSP-21489 I2C and setup the DS1388 RTC. The timing diagram shows the address byte to the RTC, but the RTC responds with ANAK. The ninth clock cycle does not occur

when SDA is low.

Any suggestions to make this work are appreciated.

Thanks

Dan

I have tried many variations for the I2C configuration, the latest one is shown below.

void Master_TWI_Init(void)
{
	// Prescale = fPCLK/10 MHz
	//

	*pTWIMITR = (0x14) | TWIEN;
	// Registers specific to Master

	// CLKDIV = TWI SCL period ÷ 10 MHz time reference
	// CLKDIV = (1/100 KHz) / 100 ns = 100
	// For 40 - 60 duty cycle, CLKHI = 40 and CLKLOW = 60

	*pTWIDIV = 	(CLKHI << 8) | CLKLOW;
	//*pTWIDIV = 	0x6464;

	// The address of the slave which needs to be accessed
	*pTWIMADDR = 0x68;  //0x00; //For general call support

	// The first data to be transmitted to the slave
	//*pTXTWI8 = 0x0001;

	// Configure the TWIFIFOCTL register to generate interrupt for each data byte
	*pTWIFIFOCTL = TWITXFLUSH | TWIRXFLUSH;
	*pTWIFIFOCTL = 0;

	// Enable the TWI interrupts
#ifdef INTERRUPT_MODE
	*pTWIIMASK |= TWITXINT;
#endif

	// Enable the master control register
	//*pTWIMCTL = (N << 6) ;
	*pTWIMCTL |= TWIRSTART;
	*pTWIMCTL |= TWIMDIR;
	//*pTWIMCTL |= TWIFAST;
	*pTWIMCTL |= TWIDCNT1;
	*pTWIMCTL |= TWIMEN;
}