HCS08: IIC MST-Bit cannot be set (MC9S08DZ60, IIC-Master-Mode)

alexanderbuerge — Thu, 25 Jul 2013 07:21:06 GMT

Hello all,

i am having a problem with IIC Master Mode at MC9S08DZ60CLC MCU. Since two days I try to figure out how to send anything on IIC-bus.

What I did: Initialize IIC -> Try to send 1 byte.

What happens: Nothing (I monitor SDA, SCL with Logic-Analyzer, function verified). SDA, SCL lines stay high always.

What I can do: Toggle the two pins manually when setting them to GPIO.

What I read so far: Datasheet, AN3291 "How to Use IIC Module on M68HC08, HCS08, and HCS12 MCUs", HCS08QRUG.

Anybody has any idea what could be the problem?

I would expect that my code (at least once) generates a start condition on the bus and/or transmit the data byte...

Kind regards,

Alex

Here is my (complete!) code:

void main(void) {
MCU_init();
IICC_IICEN = 1;//Enable IIC module
IICC_TXAK = 1;// SEND ACK
IICC_MST = 0;//SLAVE MODE
IICA = 0b10;//set slave address in IICA //PTB6=SDA PTB7=SCL

//set baud rate = BUSCLK/(2xMULTx(SCL Divider))
//     MUX | ICR|
//      \\ /////
IICF = 0b10010000;//MUX=2,ICR=0x16 Speed=100Khz

IICS_SRW = 0;//R/W bit = 0
IICC_IICIE = 0;//Disable IIC interrupt

PTAD_PTAD7 = 1;

for(;;) {

   if(IICC_MST == 1){
     PTAD_PTAD7 = 0;
   }

   if(TPM1SC_TOF){

WriteBytesI2C(0xAB, 0x0);
IICC_MST = 0;

       TPM1SC_TOF = 0;
   }
            __RESET_WATCHDOG(); //By default COP is disabled with device init. When enabling, also reset the watchdog. */
} /* loop forever */
/* please make sure that you never leave main */
}

unsigned char WriteBytesI2C (unsigned char slaveAddress,unsigned char numberOfBytes){
unsigned char Temp;

/* Format the slave address to place a 0 on the R/W bit (LSB).*/
slaveAddress &= 0xFE;
IICC_IICEN = 0;
IICC_IICEN = 1;
IICS; /* Clear any pending interrupt */
IICS_IICIF=1;
IICC_MST = 0;
IICS_SRW=0;
IICC_TX = 1; /* Select Transmit Mode */
IICC_MST = 1; /* Select Master Mode (Send Start Bit) */
for(Temp=0;Temp<50;Temp++); /* Small delay */
IICD=slaveAddress; /* Send selected slave address */
return(1);
}

Re: HCS08: IIC MST-Bit cannot be set (MC9S08DZ60, IIC-Master-Mode)

weapon — Thu, 25 Jul 2013 09:47:10 GMT

Hi Buergel,

I attached one IIC driver for your reference.

Re: HCS08: IIC MST-Bit cannot be set (MC9S08DZ60, IIC-Master-Mode)

Monica — Wed, 07 Aug 2013 01:25:27 GMT

Hello Alexander,

were these divers helpful? Don't forget to keep us posted :smileyhappy:

Best,

Monica.

topic HCS08: IIC MST-Bit cannot be set (MC9S08DZ60, IIC-Master-Mode) in 8-bit Microcontrollers

HCS08: IIC MST-Bit cannot be set (MC9S08DZ60, IIC-Master-Mode)

Re: HCS08: IIC MST-Bit cannot be set (MC9S08DZ60, IIC-Master-Mode)

Re: HCS08: IIC MST-Bit cannot be set (MC9S08DZ60, IIC-Master-Mode)