cpp/radio/Scrambler.cpp

// --------------------------------------------------------------
#include <string.h>
#include <math.h>
#include <stdint.h>
#include "Scrambler.hpp"

// --------------------------------------------------------------
// Scrambler
// --------------------------------------------------------------
Scrambler::Scrambler(uint32_t state, uint32_t poly)
	: m_state(state)
	, m_poly(poly)
{
}

Scrambler::~Scrambler()
{
}


uint32_t Scrambler::stateGet()
{
	return m_state;
}

void Scrambler::stateSet(uint32_t state)
{
	m_state = state;
}

uint8_t Scrambler::process(uint8_t src)
{
	uint8_t res = (uint8_t)(src ^ m_state);

	for (uint32_t i=0; i < 8; i++)
	{
		if (m_state & 0x0001)
		{
			m_state = (m_state >> 1) ^ m_poly;
		}
		else
		{
			m_state = (m_state >> 1);
		}
	}
	return res;
}

void Scrambler::process(uint8_t *pSrcDst, uint32_t len)
{
	while(len--)
	{
		*pSrcDst = process(*pSrcDst);
		pSrcDst++;
	}
}

// --------------------------------------------------------------