#include <stdint.h>
#include <stdbool.h>
#include "tm4c123gh6pm.h"

#define STCTRL *((volatile long *) 0xE000E010)
#define STRELOAD *((volatile long *) 0xE000E014)
#define STCURRENT *((volatile long *) 0xE000E018)

#define COUNT_FLAG  (1 << 16)

#define ENABLE      (1 << 0)

#define CLKINT      (1 << 2)
#define MASK_BITS 0x11

void GPIOF_config(void);
void GPIOF_int_config(void);

void main(void)
    {
    SYSCTL_RCC_R &= ~(1 << 20);
    SYSCTL_RCGC0_R |= 0x00100000;
    SYSCTL_RCGCPWM_R = 0x3;


    SYSCTL_RCGC2_R |= 0x20;
    GPIO_PORTF_LOCK_R = 0x4C4F434B;     /* unlock commit register*/
    GPIO_PORTF_CR_R = 0x1F;
    GPIO_PORTF_DEN_R= 0x1F;
    GPIO_PORTF_DIR_R= 0x0E;
    GPIO_PORTF_PUR_R = 0x11;


    GPIOF_config();
    GPIOF_Interrupt_config();
    GPIO_PORTF_AFSEL_R |= 0x02;
    GPIO_PORTF_PCTL_R |= 0x50;

    PWM1_2_CTL_R= 0x00000000;   //PWM module 1, generator 2 is disabled
    PWM1_2_GENB_R |= 0x80E;     //PWM module 1 , generator 2 signal B , invert on compB down count,high on load and low on zero
    PWM1_2_LOAD_R = 0xA0;       //load value is 160 for 100kHz signal
    PWM1_2_CMPB_R = 0x50;       //compA value is 80 for 50% duty cycle
    PWM1_2_CTL_R |=0x01;        //pwm block is enabled
    PWM1_ENABLE_R |=(1<<5);     //m1pwm5 signal is given to the pin

    while(1);

    }

void GPIOF_int_config()
    {
    GPIO_PORTF_IM_R &= ~MASK_BITS;
    GPIO_PORTF_IS_R &= ~MASK_BITS;
    GPIO_PORTF_IBE_R |= MASK_BITS;
    NVIC_PRI7_R = (NVIC_PRI7_R & 0xFF1FFFFF) | (2 << 21);
    NVIC_EN0_R |= (1 << 30);
    GPIO_PORTF_ICR_R = MASK_BITS;
    GPIO_PORTF_IM_R |= MASK_BITS;
    }

void GPIOF_INT_Handler(void)
    {
    GPIO_PORTF_IM_R &= ~MASK_BITS;

    int i;
    if(GPIO_PORTF_RIS_R & ~MASK_BITS)
        {
        for(i=0;i<160000;i++){}
            if(~(GPIO_PORTF_DATA_R)&0x01)
                {
                STCURRENT = 0;
                STRELOAD = 1000000*8;

                STCTRL |= (CLKINT | ENABLE);
                }
            else
                {
                if(STCTRL & COUNT_FLAG)
                    {
                    STCTRL = 0;
                    if(PWM1_2_CMPB_R < 155)
                        {
                        PWM1_2_CMPB_R += 5;
                        }
                    }
                else
                    {
                    STCTRL = 0;

                    if(PWM1_2_CMPB_R > 5)
                        {
                        PWM1_2_CMPB_R -= 5;

                        }
                    }

                }

        }
    GPIO_PORTF_ICR_R = MASK_BITS;
    GPIO_PORTF_IM_R |= MASK_BITS;
    }