signal_processing_vorlage/software/signal_processing/crc.c

#include "system/task_crc.h"
#include "system/data_channel.h"
#include "system/float_word.h"
//#include <zlib.h> 				/* c-library for crc32() */
#include <stddef.h>					/* for "size_t" */


uint32_t crc32(const char *s,size_t n) {
	uint32_t crc=0xFFFFFFFF;
	for(size_t i=0;i<n;i++) 
	{
		char ch=s[i];
			for(size_t j=0;j<8;j++) {
				uint32_t b=(ch^crc)&1;
				crc>>=1;
				if(b) crc=crc^0xEDB88320;
				ch>>=1;
		}
	}
	return ~crc;
}




int task_crc_run( void * task ) {

    // TODO

	crc_config * crc = ( crc_config * ) task;
	uint32_t data_channel_base = crc->base.sink;
	data_channel_clear( data_channel_base);

	float_word crc_res;
	float_word crc_input;

	for ( uint32_t i = 0; i < DATA_CHANNEL_DEPTH; ++i )
	{
		data_channel_read(crc->base.sources[0], (uint32_t*)&crc_input.value);
		
		crc_res.word = crc32((const void *)&crc_input, sizeof(crc_input));
	
	}


	data_channel_write( data_channel_base, crc_res.word );


    return 0;
}