#include "project.h"

int check_parity (uint8_t *d, unsigned s, unsigned e, uint8_t p)
{
  unsigned i;

  for (i = s; i <= e; ++i)
    p ^= d[i];

  return !p;
}


unsigned bcd (uint8_t *d, unsigned s, unsigned e)
{
  unsigned ret = 0, c, i;

  for (i = e, c = 1 ; i >= s; --i) {

    if (d[i]) ret += c;


    if (c & 0x77777777)
      c <<= 1;
    else {
      c >>= 3;
      c *= 10;
    }
  }

  return ret;
}



unsigned le_bcd (uint8_t *d, unsigned s, unsigned e)
{
  unsigned ret = 0, c, i;

  for (i = s, c = 1 ; i <= e; ++i) {

    if (d[i]) ret += c;

    if (c & 0x77777777)
      c <<= 1;
    else {
      c >>= 3;
      c *= 10;
    }


  }

  return ret;
}


unsigned xtoi (char c)
{
  if ((c >= '0') && (c <= '9')) return c - '0';

  if ((c >= 'a') && (c <= 'f')) return 0xa + (c - 'a');

  if ((c >= 'A') && (c <= 'F')) return 0xA + (c - 'A');

  return 0;
}