/*
 * Read switches and use the data to set LEDs on the Digilent Orbit BoosterPack.
 * The switches are connected to the MCU as:
 * SW1  PA7
 * SW2  PA6
 * BTN1 PD2
 * BTN2 PE0
 * The LEDs are connected to the MCU as:
 * LD1 PC6
 * LD2 PC7
 * LD3 PD6
 * LD4 PB5
 * Default system clock 16 MHz is used.
 */

#include "TM4C123GH6PM.h"

int main(void) {
    volatile unsigned char readback;

    SYSCTL->RCGCGPIO |= 0x1F;       // enable clock to GPIOA, GPIOB, GPIOC, GPIOD, GPIOE
    readback = SYSCTL->RCGCGPIO;    // make sure the clock is enabled
    
    // configure input pins
    GPIOA->DIR &= ~0xC0;            // set PORTA 7, 6 as input pins
    GPIOA->DEN |= 0xC0;             // set PORTA 7, 6 as digital pins
    GPIOD->DIR &= ~0x04;            // set PORTD 2 as input pins
    GPIOD->DEN |= 0x04;             // set PORTD 2 as digital pins
    GPIOE->DIR &= ~0x01;            // set PORTE 0 as input pins
    GPIOE->DEN |= 0x01;             // set PORTE 0 as digital pins
    
    // configure output pins
    GPIOC->DIR |= 0xC0;             // set PORTC 7, 6 as output pins
    GPIOC->DEN |= 0xC0;             // set PORTC 7, 6 as digital pins
    GPIOD->DIR |= 0x40;             // set PORTD 6 as output pins
    GPIOD->DEN |= 0x40;             // set PORTD 6 as digital pins
    GPIOB->DIR |= 0x20;             // set PORTB 5 as output pins
    GPIOB->DEN |= 0x20;             // set PORTB 5 as digital pins

    for (;;) {  // infinite loop
        if(GPIOD->DATA & 0x04)      // read the BTN1 and turn on/off LD1
            GPIOC->DATA |= 0x40;
        else
            GPIOC->DATA &= ~0x40;

        if(GPIOE->DATA & 0x01)      // read the BTN2 and turn on/off LD2
            GPIOC->DATA |= 0x80;
        else
            GPIOC->DATA &= ~0x80;

        if(GPIOA->DATA & 0x80)      // read the SW1 and turn on/off LD3
            GPIOD->DATA |= 0x40;
        else
            GPIOD->DATA &= ~0x40;

        if(GPIOA->DATA & 0x40)      // read the SW2 and turn on/off LD4
            GPIOB->DATA |= 0x20;
        else
            GPIOB->DATA &= ~0x20;
    }
}

// This function is called by the startup assembly
// code to perform system specific initialization tasks.
void SystemInit(void) {
    // Grant coprocessor access
    // This is required since TM4C123G has
    // a floating point coprocessor
    SCB->CPACR |= 0x00f00000;
}