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crc.c is ready now and works as required

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badenbergra78621 2023-12-05 11:09:00 +01:00
parent 69302fa649
commit b783fe53a2
1 changed files with 39 additions and 14 deletions
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51
software/signal_processing/crc.c
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@ -3,28 +3,55 @@
#include "system/float_word.h" #include "system/float_word.h"
//#include <zlib.h> /* c-library for crc32() */ //#include <zlib.h> /* c-library for crc32() */
#include <stddef.h> /* for "size_t" */ #include <stddef.h> /* for "size_t" */
#include <stdio.h>
#if 0
#define PRINT_DEBUG_VALUES
#endif
uint32_t crc32(const char *s,size_t n) { /* used basic algo from and modified it: https://lxp32.github.io/docs/a-simple-example-crc32-calculation/*/
uint32_t crc=0xFFFFFFFF; uint32_t crc32(uint32_t *crc_res, const char *s,size_t n)
for(size_t i=0;i<n;i++)
{ {
char ch=s[i]; uint32_t crc = ~(*crc_res); // always invert the input!
for(size_t j=0;j<8;j++) {
#ifdef PRINT_DEBUG_VALUES
printf("SIZE OF SEED, INPUT & OUTPUT: %i\n", n);
printf("SEED: %08x\n", *crc_res);
printf("INPUT: %08x\n", *(uint32_t*)s);
#endif /*PRINT_DEBUG_VALUES*/
for(size_t i=0;i<n;++i)
{
unsigned char ch=s[i];
#ifdef PRINT_DEBUG_VALUES
printf("ch: %02x\n", ch);
#endif /*PRINT_DEBUG_VALUES*/
for(size_t j=0;j<8;++j) {
uint32_t b=(ch^crc)&1; uint32_t b=(ch^crc)&1;
crc>>=1; crc>>=1;
if(b) crc=crc^0xEDB88320; //if(b) crc=crc^0x04C11DB7; // Polynomial representations: NORMAL
if(b) crc=crc^0xEDB88320; // Polynomial representations: REVERSED
ch>>=1; ch>>=1;
} }
} }
#ifdef PRINT_DEBUG_VALUES
printf("OUTPUT: %08x\n", crc);
printf("~OUTPUT: %08x\n", ~crc);
getchar(); // just here for debugging step by step
#endif /*PRINT_DEBUG_VALUES*/
return ~crc; return ~crc;
} }
int task_crc_run( void * task ) { int task_crc_run( void * task )
{
// TODO // TODO
crc_config * crc = ( crc_config * ) task; crc_config * crc = ( crc_config * ) task;
@ -34,18 +61,16 @@ int task_crc_run( void * task ) {
float_word crc_res; float_word crc_res;
float_word crc_input; float_word crc_input;
crc_res.word = crc->start;
for ( uint32_t i = 0; i < DATA_CHANNEL_DEPTH; ++i ) for ( uint32_t i = 0; i < DATA_CHANNEL_DEPTH; ++i )
{ {
data_channel_read(crc->base.sources[0], (uint32_t*)&crc_input.value); data_channel_read(crc->base.sources[0], (uint32_t*)&crc_input.value);
crc_res.word = crc32(&crc_res.word,(const void *)&crc_input, sizeof(crc_input));
crc_res.word = crc32((const void *)&crc_input, sizeof(crc_input));
} }
data_channel_write( data_channel_base, crc_res.word ); data_channel_write( data_channel_base, crc_res.word );
return 0; return 0;
} }