Introduction

This is the documentation of using the picsim simulation library functions.

Library functions usage simple example

Demonstration of a simple example of using picsim library functions

picsim_simple.c

#include<picsim/picsim.h>
#include<stdio.h>
 
int main()
{
  int i;
  unsigned char val;
  //microcontroller object
  _pic pic1; 
 
  //set serial port
  pic_set_serial(&pic1,0, "/dev/tnt2",0,0,0);
  //pic_set_serial(&pic1,"COM2",0,0,0);
 
  //initialization and program loading
  pic_init(&pic1, getprocbyname("PIC16F628A"), "../../../examples/shift/shift.hex", 1, 4e6);
 
  //enable print messages of internal instruction execution (slow down the simulation speed) 
  pic1.print=1;
 
  //loop 
  for(i=0;i<1000;i++)
  {
      //execute one instruction cycle      
      pic_step(&pic1);
      //read digital pin 1
      val=pic_get_pin(&pic1, 1);
      //write digital pin 2
      pic_set_pin(&pic1, 2, val);
  }
 
  //free internal memory
  pic_end(&pic1);
} 

Makefile

 
CC= gcc
 
FLAGS= -Wall -ggdb
 
all: picsim_simple.c
    $(CC) $(FLAGS) picsim_simple.c -o picsim_simple -lpicsim
 
clean:
    rm -rf picsim_simple
 
 
 

Library functions usage realtime example

Demonstration of a realtime Linux example of using picsim library functions

realtime.c

 
#include <picsim/picsim.h>
#include <stdio.h>
#include <sys/time.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
 
 
#define FREQ 4000000L
 
static _pic pic1;
 
void timer_callback(int signum)
{
  unsigned char PORTB;
  static unsigned char PORTB_old;
  const unsigned int nsteps = 100e-3 / (4.0 / pic1.freq);
  for (int i = 0; i < nsteps; i++)
  {
    pic_step(&pic1);
 
    //READ pins
    // PORTB |= pic_get_pin(&pic1, 6);
    // use direct access instead pic_get_pin to speed up
 
    PORTB = 0;
    PORTB |= pic1.pins[6 - 1].value;       // RB0
    PORTB |= pic1.pins[7 - 1].value << 1;  // RB1
    PORTB |= pic1.pins[8 - 1].value << 2;  // RB2
    PORTB |= pic1.pins[9 - 1].value << 3;  // RB3
    PORTB |= pic1.pins[10 - 1].value << 4; // RB4
    PORTB |= pic1.pins[11 - 1].value << 5; // RB5
    PORTB |= pic1.pins[12 - 1].value << 6; // RB6
    PORTB |= pic1.pins[13 - 1].value << 7; // RB7
 
    if (PORTB != PORTB_old)
    {
      PORTB_old = PORTB;
      printf("PORTB =0x%02X\n", PORTB);
    }
  }
}
 
void ctrlc_callback(int signum)
{
  printf("end\n");
  pic_end(&pic1);
  exit(0);
}
 
int main()
{
 
  pic_init(&pic1, getprocbyname("PIC16F628A"),  "../../../examples/shift/shift.hex", 1, FREQ);
 
  struct itimerval new_timer;
  struct itimerval old_timer;
 
  new_timer.it_value.tv_sec = 0;
  new_timer.it_value.tv_usec = 100 * 1000; //100ms
  new_timer.it_interval.tv_sec = 0;
  new_timer.it_interval.tv_usec = 100 * 1000; //100ms
 
  setitimer(ITIMER_REAL, &new_timer, &old_timer);
  signal(SIGALRM, timer_callback);
  signal(SIGINT, ctrlc_callback);
 
  // Waitting forever
  while (sleep(10))
    ;
}

Makefile

 
CC= gcc
 
FLAGS= -ggdb -Wall  
 
all: realtime 
 
realtime: realtime.c
    $(CC) $(FLAGS) realtime.c -o realtime -lpicsim
 
clean:
    rm -rf realtime