led counter 0-99 embedded systems

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

#define PIO_PER_B AT91C_PIOB_PER
#define PIO_OER_B AT91C_PIOB_OER
#define PIO_CODR_B AT91C_PIOB_CODR
#define PIO_SODR_B AT91C_PIOB_SODR

#define A (1<<25)  //pin PB25
#define B (1<<24) // pin  PB24
#define C (1<<22) // pin PB22
#define D (1<<21) // pin PB21
#define E (1<<20) // pin PB20
#define F (1<<27) // pin  PB27
#define G (1<<26) // pin PB26

#define LEFT_DISPLAY (1<<28) // controls Q2 transistor, left LED
#define BRIGHTNESS (1<<29) // controls transistor Q1
#define RIGHT_DISPLAY (1<<30) // controls Q3 transistor, right LED

#define LEFT 1
#define RIGHT 0

#define DELAY 1000

 //uint32_t numeric type that guarantees 32 bits, value unsigned
uint32_t ledDecode (uint8_t digit)
{
    int number[10] = {};
    number[0] = A|B|C|D|E|F;
    number[1] = B|C;
    number[2] = A|B|D|E|G;
    number[3] = A|B|C|G|G|D;
    number[4] = F|B|G|C;
    number[5] = A|F|G|C|D;
    number[6] = A|F|G|E|D|C;
    number[7] = A|B|C;
    number[8] = A|B|C|D|E|F|G;
    number[9] = A|B|F|G|C|D;

    return number[digit];
}

void delay_ms (int delay) {
        volatile int time;
        for(time = 0; time < 25000*delay; time++);
}

void LED_Init(void) {
    *PIO_PER_B = (LEFT_DISPLAY|BRIGHTNESS|RIGHT_DISPLAY|A|B|C|D|E|F|G);
    *PIO_OER_B = (LEFT_DISPLAY|BRIGHTNESS|RIGHT_DISPLAY|A|B|C|D|E|F|G);
    *PIO_CODR_B  = (A|B|C|D|E|F|G);
    *PIO_SODR_B = (LEFT_DISPLAY|RIGHT_DISPLAY);
    *PIO_CODR_B = BRIGHTNESS;
}

void LED_display_digit(uint8_t digit, uint8_t pos) {
        *PIO_SODR_B = (LEFT_DISPLAY|RIGHT_DISPLAY); //turn off the displays
        *PIO_CODR_B=(A|B|C|D|E|F|G); //clear segments
        *PIO_SODR_B=(ledDecode(digit)); //display number
        if(pos == LEFT) {
            *PIO_CODR_B= LEFT_DISPLAY; //enable left display
        } else {
            *PIO_CODR_B= RIGHT_DISPLAY; //enable right display
        }
}

void firstPart(void) {
    int counter = 0;
    while(1)
    {
        LED_display_digit(counter, LEFT);
        delay_ms(DELAY);
        counter++;
        if(counter == 10) {
            counter = 0;
        }
    }
}

void secondPart(void) {
    int counter = 0;
    while(1) {
        int tens = counter/10;
        int unit = counter%10;
        int i;
        for(i=0; i<50; i++){
            LED_display_digit(tens, LEFT);
            delay_ms(10);
            LED_display_digit(unit, RIGHT);
            delay_ms(10);
        }
        counter++;
        if(counter == 99) {
            counter= 0;
        }
    }
}

int main(void) {

    LED_Init();
    //firstPart();
    secondPart();

    return 0;
}