/*
 * Read switches and use the data to set LEDs for TI Tiva LaunchPad
 * with Wytec EduBase.  On Wytec EduBase board, PB3-PB0 are connected
 * to the four LEDs and PD3-PD0 are connected to both the DIP switches (SW1)
 * and the pushbuton switches (SW2-SW5).
 * In order for the pushbutton switches to be effective, the DIP switches
 * must be at the off position.
 */

#include "TM4C123GH6PM.h"

int main(void)
{
    volatile unsigned char readback;
    unsigned char data;

    // enable PORTB 3-0 as output
    SYSCTL->RCGCGPIO |= 0x02;       // enable clock to GPIOB
    readback = SYSCTL->RCGCGPIO;    // make sure the colock is enabled
    GPIOB->DIR |= 0x0F;             // set PORTB 3-0 as output pins
    GPIOB->DEN |= 0x0F;             // set PORTB 3-0 as digital pins

    // enable PORTD 3-0 as input
    SYSCTL->RCGCGPIO |= 0x08;       // enable clock to GPIOD
    readback = SYSCTL->RCGCGPIO;
    GPIOD->DIR &= ~0x0F;            // set pin 3-0 as input
    GPIOD->AMSEL &= ~0x0F;          // disable analog functions
    GPIOD->DEN |= 0x0F;             // set pin 3-0 as digital pins

    for (;;)
    {
        data = GPIOD->DATA;         // read the switches and write to LEDs
        GPIOB->DATA = data;
    }
}

// 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;
}