PentHertz
/
srsLTE
mirror of https://github.com/PentHertz/srsLTE.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Restored old CRC

This commit is contained in:
ismagom 2014-05-13 16:43:16 +01:00
parent bcdf2f0886
commit 887c3a8e80
2 changed files with 61 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lte/include/lte/fec/crc.h
View File

@ -61,5 +61,7 @@ typedef struct {
int crc_init(crc_t *crc_par);
unsigned int crc_attach(char *bufptr, int len, crc_t *crc_params);
unsigned int crc(unsigned int crc, char *bufptr, int len,
int long_crc,unsigned int poly, int paste_word);
#endif

59
lte/lib/fec/src/crc.c
View File

@ -154,3 +154,62 @@ unsigned int crc_attach(char *bufptr, int len, crc_t *crc_params) {
//Return CRC value
return crc;
}
unsigned int cword;
unsigned int icrc1(unsigned int crc, unsigned short onech,int long_crc,
int left_shift,unsigned int poly)
{
int i;
unsigned int tmp=(unsigned int) (crc ^ (onech << (long_crc >> 1) ));
for (i=0;i<left_shift;i++) {
if (tmp & (0x1<<(long_crc-1)))
tmp=(tmp<<1)^poly;
else
tmp <<= 1;
}
return tmp;
}
unsigned int crc(unsigned int crc, char *bufptr, int len,
int long_crc,unsigned int poly, int paste_word) {
int i,k;
unsigned int data;
int stop;
unsigned int ret;
cword=crc;
k=0;
stop=0;
while(!stop) {
data=0;
for (i=0;i<long_crc/2;i++) {
if (bufptr[k] && k<len)
data|=(0x1<<(long_crc/2-1-i));
k++;
if (k==len) {
stop=1;
i++;
break;
}
}
cword=(unsigned int) (icrc1((unsigned int) (cword<<long_crc>>long_crc),
data,long_crc,i,poly)<<long_crc)>>long_crc;
}
ret=cword;
if (paste_word) {
cword<<=32-long_crc;
for (i=0;i<long_crc;i++) {
bufptr[i+len]=((cword&(0x1<<31))>>31);
cword<<=1;
}
}
return (ret);
}