test.c

   1 /*
   2  toggle_led.c
   3  Toggles an LED on Pin 1 of PORTB on a PIC16F627. Written
   4  as a sample for the article on using SDCC and GPSIM in
   5  Linux. http://www.micahcarrick.com/v2/content/view/14/4/
   6
   7  Compile: sdcc --debug -mpic14 -p16f628a test.c
   8  Simulate: gpsim -c env.conf -s test.cod
   9
  10 */
  11
  12 /* Define processor and include header file. */
  13 #define __16f628a
  14 #include "pic/pic16f628a.h"
  15
  16 /* Setup chip configuration */
  17 typedef unsigned int config;
  18 config at 0x2007 __CONFIG = _CP_OFF &
  19  _WDT_OFF &
  20  _BODEN_OFF &
  21  _PWRTE_OFF &
  22  _ER_OSC_CLKOUT &
  23  _MCLRE_ON &
  24  _LVP_OFF;
  25
  26 #define b0 0x01 /* pin 1 on PORTB */
  27 #define B_OUTPUTS 0xfa /* value used to setup TRISB */
  28
  29
  30 /* TXSTA */
  31 static void setup() {
  32     /* PORTB.1 is an output pin */
  33     TRISB = B_OUTPUTS;
  34     /* USART setup */
  35     //BRGH = 1;                           // baudrate class
  36     SPBRG = 25;
  37
  38     SYNC = 0; /* Asynchronous */
  39     SPEN = 1; /* Serial port enable*/
  40     TXEN = 1; /* Tx enable */
  41 }
  42
  43 static void send_byte(char alpha) {
  44     TXREG = alpha;
  45 }
  46
  47 void main(void) {
  48     char alpha = 'a';
  49     int i;
  50
  51     setup();
  52
  53     TXREG = alpha;
  54     while(1) { /* Loop forever */
  55         /* toggle bit 1 */
  56         //PORTB = (PORTB ^ b0);
  57         while (TRMT);
  58         for (i = 0; i < 2000; i++);
  59         send_byte(alpha);
  60         alpha++;
  61         if (alpha > 'z')
  62             alpha = 'a';
  63     }
  64 }