#include <stdint.h>
#include <stdbool.h>
#include "tm4c123gh6pm.h"
// SysTick memory-mapped registers
#define STCTRL *((volatile uint32_t *) 0xE000E010)          // CONTROL AND STATUS
#define STRELOAD *((volatile uint32_t *) 0xE000E014)        // RELOAD VALUE
#define STCURRENT *((volatile uint32_t *) 0xE000E018)       // CURRENT VALUE
#define CLOCK_HZ 16000000       // CLOCK FREQUENCY OF EK-TM4C123GXL
#define SYSTICK_RELOAD_VALUE(us) ((CLOCK_HZ / 1000000) * (us) - 1)  // SYSTICK RELOAD VALUE

void GPIO_PORT_F_init(void)
{
    SYSCTL_RCGC2_R |= 0x00000020;             // ENABLE CLOCK TO GPIOF
    GPIO_PORTF_LOCK_R = 0x4C4F434B;           // UNLOCK COMMIT REGISTER
    GPIO_PORTF_CR_R   = 0x1F;                 // MAKE PORTF0 CONFIGURABLE
    GPIO_PORTF_DEN_R  = 0x1F;                 // SET PORTF DIGITAL ENABLE
    GPIO_PORTF_DIR_R  = 0x0E;                 // SET PF0, PF4 as input and PF1, PF2 and PF3 as output
    GPIO_PORTF_PUR_R  = 0x11;                 // PORTF PF0 and PF4 IS PULLED UP

    NVIC_EN0_R |= 1 << 30;
    GPIO_PORTF_IS_R  = 0x00;                 // Make it edge-sensitive
    GPIO_PORTF_IBE_R = 0x00;                 // Trigger on one edge
    GPIO_PORTF_IEV_R = 0x00;                 // Falling edge event
    GPIO_PORTF_IM_R  |= 0x11;                // Unmask interrupts for PF0 and PF4
}
void systick_setting(void)                      // SYSTICK SETUP FUNCTION
{
    STRELOAD = SYSTICK_RELOAD_VALUE(1000);     // RELOAD VALUE FOR 1ms
    STCTRL |= (1 << 0) | (1 << 2);              // Enable SysTick with system clock
    STCURRENT = 0;                               // Clear current value
}