// uart_test.c

/*  Copyright (C) 2017 H.Poetzl
**	
**  This program is free software: you can redistribute it and/or
**  modify it under the terms of the GNU General Public License
**  as published by the Free Software Foundation, either version
**  2 of the License, or (at your option) any later version.
*/

// ------------------------------------------------
// configuration

#define NO_BIT_DEFINES
#include <pic16f18344.h>
#include <stdint.h>

#define CONFIG(k, n) __code static char __at _ ## k __ ## k = n

CONFIG(CONFIG1,  _FEXTOSC_OFF & _RSTOSC_HFINT1 & _CSWEN_ON & _CLKOUTEN_OFF);
CONFIG(CONFIG2,  _MCLRE_ON & _WDTE_OFF & _PPS1WAY_OFF);

#define CPU_NDIV	0


#define out_ser_ch(c) do {                      \
        while (!PIR1bits.TXIF);                 \
        TX1REG = (c);                           \
        __asm                                   \
            NOP                                 \
        __endasm;                               \
    } while (0)

#define out_ser_str0(s) do {                    \
        const char *_p = (s);                   \
                                                \
        while (*_p)                             \
            out_ser_ch(*_p++);                  \
    } while (0)

#define out_ser_str(s, n) do {                  \
        const char *_p = (s);                   \
        unsigned char _n = (n);                 \
                                                \
        while (_n--)                            \
            out_ser_ch(*_p++);                  \
    } while (0)

#define out_ser_flush() do {                    \
        while (!PIR1bits.TXIF);                 \
        while (!TX1STAbits.TRMT);               \
    } while (0)


// --------------------------------------------------
// and our main entry point

void main()
{
    // all digital
    ANSELA = 0;
    ANSELB = 0;
    ANSELC = 0;

    // all input
    TRISA = 0xFF;
    TRISB = 0xFF;
    TRISC = 0xFF;

    // all push pull
    ODCONA = 0x00;
    ODCONB = 0x00;
    ODCONC = 0x00;

    // all outputs '1'
    LATA = 0xFF;
    LATB = 0xFF;
    LATC = 0xFF;



    /* configure oscillator */
    OSCCON3bits.CSWHOLD = 0;
    OSCCON1bits.NDIV = CPU_NDIV;

    /* configure EUSART */
    TX1STA = 0;
    TX1STAbits.TXEN = 1;
    TX1STAbits.BRGH = 1;

    RC1STA = 0;
    RC1STAbits.SPEN = 1;
    RC1STAbits.CREN = 0;

    BAUD1CON = 0;
    BAUD1CONbits.BRG16 = 1;
    BAUD1CONbits.WUE = 0;
    
    SP1BRG = 0;
    SP1BRGH = 0;

    /* disable unused modules */
    PMD0 = 0b00000101;	/* All but Clock Net,CLKR,FVR */
    PMD1 = 0b11111010;	/* All but Timer 0,2 */
    PMD2 = 0b01000110;	/* All but ADC */
    PMD3 = 0b11111110;	/* All but CCP1 */
    PMD4 = 0b00000010;	/* All but UART1*/
    PMD5 = 0b00011101;	/* All but CLC1 */

    /* PPS */
    PPSLOCKbits.PPSLOCKED = 0;

    RA0PPS = 0b10100;			/* TX1 on ICSPDAT */


    while (1) {
	uint16_t i;

	out_ser_str0("Hello World!\n");
	out_ser_flush();
	
	for (i=0; i<20000; i++);
    }

}