CSE3215_Exam.c

#define BUF_SIZE    8

extern volatile char buffer[BUF_SIZE];
extern volatile int index = 0;

#pragma CODE_SEG __NEAR_SEG NON_BANKED
interrupt void RTI_ISR(void) {
  absoluteTime++;
  /* clear RTIF bit */
  CRGFLG = 0x80;
}

#pragma CODE_SEG __NEAR_SEG NON_BANKED
interrupt void TOF_ISR(void) {
    PORTA = PORTA+1;
    TFLG2 = 0x80;
}

#pragma CODE_SEG __NEAR_SEG NON_BANKED
interrupt void SCI0R_ISR(void) {

    if(index > 8)
        index = 0;
    buffer[index++] = SCI1DRL; /*Read from register*/
}

#pragma CODE_SEG __NEAR_SEG NON_BANKED
interrupt void OC2_ISR(void) {
    TC2 = TC2 + 15000/2 /*Half period*/;
    TFLG1 = 0x04; /*Clear interrupt flag*/
}

interrupt void IC1_ISR(void) {
    time = TC2;
    TFLG1 = 0x02; /*Clear interrupt flag*/
}


#pragma CODE_SEG DEFAULT
static void RTIInit(void) {
  /* setup of the RTI interrupt frequency */
  /* adjusted to get 1 millisecond (1.024 ms) with 16 MHz oscillator */
  RTICTL = 0x1F; /* set RTI prescaler */
  CRGINT = 0x80; /* enable RTI interrupts */
}

static void TimerInit(void){

    /* 10ms*(24000000/16) = 15000 */
    DDRA = 0xFF; /* PORTA output*/
    TSCR1 = 0x80; /* Turn on timer*/
    TSRC2 = 0x85; /*Enable timer overflow, set prescalar */
    TFLG2 = 0x80; /*Clear timer interrupt flag*/
}

static void PWMInit(void){
    PWMCTL = 0x00;  /* 8-bit Mode */
    PWMPOL = 0xFF;  /* High polarity mode */
    PWMCAE = 0x00;  /* Left-Aligned */
    PWMPRCLK = PWMPRCLK & ~0x07;  /* PCKA = 0 */
    PWMCLK = PWMCLK | 0x01;  /* PCLK0 = 1 */
    PWMSCLA = 30;
    PWMPER0 = 200; /*Total period of duty cycle*/
    PWME = PWME | 0x01;  /* Enable PWM Channel 0 */
    PWDTY0 = 120;  /* 60% duty cycle on Channel 0(120/PWMPER0) */
}

static void SPI0_Init(void){
    // SPI communication initialization as a master
    SPI0BR  = 0b00100101;    // Baud rate = 24MHz/16 = 1.5MHz 0x53;
    SPI0CR2 = 0b00010000;  // SPI0CR2_SPISWAI=1 : Stop SPI clocks when in wait mode
    SPI0CR1 = 0b01010010;  // Enable SPI ; Master mode ; CPHA = 1 ;

    WOMS = 0;
}

static void SCI0_Init(void){
    SCI1BDL = 156; /* Set BAUD rate to 9,600 */
    SCI1BDH = 0;

    SCI1CR1 = 0x00;
    SCI1CR2 = 0x36; /*Recieve Interrupts, Transmit, Recieve enable */
}

static void OC2_Init(void){
    TSCR1 = 0x80; /*Enable Timers */
    TSCR2 = 0x04; /*Set prescale to 16(0.666us) */
    TIOS = 0x04; /* Set IOS2 as Output Compare*/
    TCTL2 = 0x10; /*Toggle on compare*/
    TFLG1 = 0x04; /*Clear OC2 flag*/
    TIE = 0x04; /*Enable OC2 interupts*/
}

static void IC1_Init(void){
    TSCR1 = 0x80; /* Turn on timer subsystem */
    TSCR2 = 0x05; /* Set prescaler for divide by 32 */
    /* 87.38 ms overflow time */
    TIOS = TIOS & ~0x02; /*only IC1 is low for input */
    TCTL4 = 0x04 /*EDG1A enabled, captures rising edge*/
    TFGL1 = 0x02 /*Clear flag 1*/
}

static void ADTD0_Init(void){
    ATD0CTL2 = 0x80; /* Power up A/D, no interrupts */
    ATD0CTL3 = 0x00; /* Doe eight conversions */
    ATD0CTL4 = 0x85; /* 8-bit mode */
    ATD0CTL5 = 0xA4; /* Cont conversion, right justified */
    adcvalue = ATD0DR0H; /* Grab the value from register*/
}

void SCI0_OutChar(char data) {

    while((SCI0SR1 & TDRE) == 0){};
    SCI0DRL = data;
}

char SCI0_InChar(void){
    /* Only used when Recieve Interrupt disabled*/
    while((SCI0SR1 & RDRF) == 0){};
    return(SCI0DRL);
}

char SCI0_ReadBuffer(void){
    char data = buffer[index--];
    if(index < 0)
        index = 0;
    return data;
}

static void SPI0_send(char x){
    // Send a byte to the slave blocking(CPU will wait)
    while( SPI0SR_SPTEF == 0); // Wait until SPIDR becomes empty.
    SPI0DR = 0xAA;              //  Clear the flag SPI0SR_STEF

    while( SPI0SR_SPIF == 0 );   // Wait until the end of an SPI transfer.
    data = SPI0DR;
}

char SPI0_receive(void) {
    // Receive a byte from the slave
    while(SPI0SR_SPTEF == 0);  // Wait until the SPI0DR is empty
    SPI0DR = 0x00;                         // Read SPI0DR to clear the SPI0SR_SPTEF flag
    while(SPI0SR_SPIF == 0);      // Wait until a SPI transfer is finished
    return SPI0DR;                         // Write the received data to data
}


 void main(void)
  RTIInit();
  TimerInit();
  PWMInit();
  SPI0_Init();
  EnableInterrupts;

  SPI0_send('a');

  for(;;)
  {

  }

/* Interrupt Vector Table
 * const IsrFunc _vectab[] @0x3e00 /*0xFF80 =
{
  (IC1_ISR)0,
  (OC2_ISR)0,
  (RTI_ISR)0,
  (TOF_ISR)0,
  (SCI0R_ISR)0,
*/