/* p4_4.c: This program sets up UART5 on TI ARM LaunchPad (TM4C123GH6PM) to do terminal echo. When a key is pressed at the terminal emulator of the PC, the character is received by UART5 and it is sent out of UART5 back to the terminal. */
/* UART5 Tx is on PE5, Rx is on PE4. */
/* Use TeraTerm to see that the keys are echoed. */

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

char UART5Rx(void); 
void UART5Tx(char c);
void delayMs(int n);

int main(void) 
{
    char c;
    
    SYSCTL->RCGCUART |= 0x20;  /* provide clock to UART5 */
    SYSCTL->RCGCGPIO |= 0x10;  /* Enable clock to PORTE */

    /* UART5 initialization */
    UART5->CTL = 0;         /* disable UART5 */
    UART5->IBRD = 104;      /* 16MHz/16=1MHz, 1MHz/104=9600 baud rate */
    UART5->FBRD = 11;       /* fraction part, see Example 4-4 */
    UART5->CC = 0;          /* use system clock */
    UART5->LCRH = 0x60;     /* 8-bit, no parity, 1-stop bit */
    UART5->CTL = 0x301;     /* enable UART5, TXE, RXE */
    
    /* UART5 TX5 and RX5 use PE5 and PE4. Set them up. */
    GPIOE->DEN = 0x30;      /* make PE5, PE4 as digital */
    GPIOE->AMSEL = 0;       /* turn off analog function */
    GPIOE->AFSEL = 0x30;    /* use PE5, PE4 alternate function */
    GPIOE->PCTL = 0x00110000;     /* configure PE5, PE4 for UART5 */

    delayMs(1);             /* wait for output line to stabilize */
    UART5Tx('>');           /* send the prompt character */
    
    for(;;)
    {
        c = UART5Rx();          /* get a character from UART */
        UART5Tx(c);             /* echo it back to the terminal */
    }
}

/* UART0 Receive */
char UART5Rx(void)  
{
    char c;
    while((UART5->FR & 0x10) != 0); /* wait until the buffer is not empty */
    c = UART5->DR;                  /* read the received data */
    return c;                       /* and return it */
}

/* UART5 Transmit */
void UART5Tx(char c)  
{
    while((UART5->FR & 0x20) != 0); /* wait until Tx buffer not full */
    UART5->DR = c;                  /* before giving it another byte */
}

/* Append delay functions and SystemInit() here */