PIT timer

#include <stdint.h>
#include <stdbool.h>
#include "include/AT91SAM9263.h"

#define PIO_PER_B (volatile unsigned int *) AT91C_PIOB_PER //enables PIO control of corresponding pin
#define PIO_OER_B (volatile unsigned int *) AT91C_PIOB_OER  //enables output
#define PIO_SODR_B (volatile unsigned int *) AT91C_PIOB_SODR//sets data on the I/O line
#define PIO_CODR_B (volatile unsigned int *) AT91C_PIOB_CODR //clears data on I/O line

#define PMC_PCER (volatile unsigned int *) AT91C_PMC_PCER

#define PIO_PER_C (volatile unsigned int *) AT91C_PIOC_PER
#define PIO_OER_C (volatile unsigned int *) AT91C_PIOC_OER
#define PIO_SODR_C (volatile unsigned int *) AT91C_PIOC_SODR
#define PIO_CODR_C (volatile unsigned int *) AT91C_PIOC_CODR
#define PIO_ODR_C (volatile unsigned int *) AT91C_PIOC_ODR //disable output (enables input) on I/O line
#define PIO_PUER_C (volatile unsigned int *) AT91C_PIOB_PPUER   //pull-up

#define PIO_PDSR_C (volatile unsigned int *) AT91C_PIOC_PDSR //pin data status, when 0 on I/O line returns 0
#define DELAY_TIME 100
#define LED1 (1 << 8) //PB8
#define LED2 (1 << 29) //PC29
#define RIGHTCLIC (1 << 4) //PC4
#define LEFTCLIC (1 << 5) //PC5
#define PID4 (1 << 4) //enable clock input for port C


#define PIT_MR (volatile unsigned int *) AT91C_PITC_PIMR //RW mode register
#define PIT_PIVR (volatile unsigned int *) AT91C_PITC_PIVR //reading this register clears counter and flag
#define PIT_SR  (volatile unsigned int *) AT91C_PITC_PISR //status register, when counting =0
#define PITIEN (1<<25) //interapt register
#define PITEN (1<<24) // PIT enable
#define DELAY_IN_SEC (0.001)
#define PIV ( (DELAY_IN_SEC / (160*0.000000001) ) - 1)

void delay_ms (int delay){
    delay *=10;
    unsigned int i;
    for(i = 0; i < delay; i++){
        volatile unsigned int j;
        for(j=0; j<1275; j++);
    }
}

void ConfigureLEDs (void)
{
    *PIO_PER_B = LED1;
    *PIO_OER_B = LED1;

    *PIO_PER_C = LED2;
    *PIO_OER_C = LED2;

    *PIO_SODR_B = LED1;
    *PIO_SODR_C = LED2;

}

void ConfigureButtons (void) {
    //enable peripherial control of both pins
    *PIO_PER_C = RIGHTCLIC;
    *PIO_PER_C = LEFTCLIC;

    //disable output, which means that the port works as input
    *PIO_ODR_C = RIGHTCLIC;
    *PIO_ODR_C = LEFTCLIC;

    *PIO_PUER_C = RIGHTCLIC;
    *PIO_PUER_C = LEFTCLIC;

    //enable clock
    *PMC_PCER = PID4;

}

void PIT_Init (void) {
    *PIT_MR = PIV;
    *PIT_MR &= ~(PITIEN | PITEN);
    //1, program delay
    volatile unsigned int clear = *PIT_PIVR; //reset counter and clear flag
}

void PIT_delay_ms (int delay_in_ms ) {
    volatile unsigned int clear;
    int counter = 0;
    for(counter; counter < delay_in_ms; counter++) {
        *PIT_MR |= PITEN; // start timer
        while(*PIT_SR == 0){} //wait for the flag
        *PIT_MR &= ~(PITEN); //stop timer
        clear = *PIT_PIVR; //clear clock
    }
}

void CheckButton (void) {
        if ( *PIO_PDSR_C == (1 << 4 ) ) {
            *PIO_CODR_C = LED2;
        }

        if ( *PIO_PDSR_C == (1 << 5 ) ) {
            *PIO_SODR_C = LED2;
        }
}


int main(void) {


    ConfigureLEDs();
    ConfigureButtons();
    PIT_Init();
    while(1){

        int counter;
        *PIO_CODR_B = LED1; //turn on LED1

        for(counter = 0; counter < 100; counter++){
            PIT_delay_ms(10);
            CheckButton();
        }

        *PIO_SODR_B = LED1; //turn off LED2

        for(counter = 0; counter < 100; counter++){
            PIT_delay_ms(10);
            CheckButton();
        }
    }
}