mirror of
https://github.com/RobTillaart/Arduino.git
synced 2024-09-20 00:55:58 -04:00
82 lines
1.5 KiB
C++
82 lines
1.5 KiB
C++
//
|
|
// FILE: Fletcher32.cpp
|
|
// AUTHOR: Rob Tillaart, Daniel Mohr
|
|
// PURPOSE: Arduino class for Fletcher32
|
|
// URL: https://github.com/RobTillaart/Fletcher
|
|
|
|
|
|
#include "Fletcher32.h"
|
|
|
|
// UINT16_MAX = 65535UL = ((((uint32_t) 1) << 16) - 1)
|
|
#define FLETCHER_32 UINT16_MAX
|
|
|
|
|
|
Fletcher32::Fletcher32()
|
|
{
|
|
begin();
|
|
}
|
|
|
|
|
|
void Fletcher32::begin(uint16_t s1, uint16_t s2)
|
|
{
|
|
_s1 = (s1 == FLETCHER_32) ? 0 : s1;
|
|
_s2 = (s2 == FLETCHER_32) ? 0 : s2;
|
|
_count = 0;
|
|
}
|
|
|
|
|
|
void Fletcher32::add(uint16_t value)
|
|
{
|
|
_count++;
|
|
#ifdef ARDUINO_ARCH_AVR
|
|
unsigned int t = _s1;
|
|
// Serial.println("__builtin_uadd_overflow");
|
|
if (__builtin_uadd_overflow(t, value, &t)) {
|
|
t++;
|
|
}
|
|
_s1 = t;
|
|
t = _s2;
|
|
if (__builtin_uadd_overflow(t, _s1, &t)) {
|
|
t++;
|
|
}
|
|
_s2 = t;
|
|
#elif defined(ARDUINO_ARCH_SAMD) || defined(ESP32) || defined(ESP8266)
|
|
_s1 += value;
|
|
_s1 = (_s1 & FLETCHER_32) + (_s1 >> 16);
|
|
_s2 += _s1;
|
|
_s2 = (_s2 & FLETCHER_32) + (_s2 >> 16);
|
|
#else
|
|
_s1 += value;
|
|
if (_s1 >= FLETCHER_32) _s1 -= FLETCHER_32;
|
|
_s2 += _s1;
|
|
if (_s2 >= FLETCHER_32) _s2 -= FLETCHER_32;
|
|
#endif
|
|
}
|
|
|
|
// NOTE: padding with zero's error
|
|
//
|
|
void Fletcher32::add(const uint16_t * array, uint16_t length)
|
|
{
|
|
while (length--)
|
|
{
|
|
add(*array++);
|
|
}
|
|
}
|
|
|
|
uint32_t Fletcher32::getFletcher()
|
|
{
|
|
if (_s1 >= FLETCHER_32) _s1 -= FLETCHER_32;
|
|
if (_s2 >= FLETCHER_32) _s2 -= FLETCHER_32;
|
|
return (((uint32_t)_s2) << 16) | _s1;
|
|
};
|
|
|
|
|
|
uint32_t Fletcher32::count()
|
|
{
|
|
return _count;
|
|
};
|
|
|
|
|
|
// -- END OF FILE --
|
|
|