ATMega640 MSPIM SS-Timing

void MSPIM_Init(void)   

{

   DDRD |= (1<<PD6); //CS as Output

   DDRE |= (1<<PE2); //XCK0 as Output

   UBRR0H = 0;

   UBRR0L = 7;

   /*0,5Mbps at 8MHz Clock*/

    // enable RX and TX and set interrupts on rx complete

    UCSR0B = (1 << RXEN0) | (1 << TXEN0) | (1 << RXCIE0);

    // MSPIM Mode, MSB first, PHA=1, POL=0

    UCSR0C = (0 << UCPOL0) | (1 << UMSEL01) | (1 << UMSEL00) | (0 << 2)| (1 << 1);

}

void MSPIM_Transmit( unsigned char data ) 

{

  /* Wait for empty transmit buffer */

  while ( !( UCSR0A & (1<<UDRE0)) );

    UDR0 = data;

}

void TestTransmit(void){

  PORTD &= ~(1<<PD6); //set SS low

  MSPIM_Transmit(0x01);

  MSPIM_Transmit(0xaa);

  MSPIM_Transmit(0x01);

  while ( !( UCSR0A & (1<<6)) ); //Wait for TX Complete Flag

  PORTD |= (1<<PD6); // set SS high

}