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fix: fdx crc calc

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This commit is contained in:
iceman1001 2019-10-30 15:44:57 +01:00
commit 01b149efa5
3 changed files with 36 additions and 14 deletions
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17
common/crc16.c
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@ -46,6 +46,9 @@ void init_table(CrcType_t crctype) {
case CRC_KERMIT:
generate_table(CRC16_POLY_CCITT, true);
break;
case CRC_11784:
generate_table(CRC16_POLY_CCITT, false);
break;
case CRC_NONE:
crc_table_init = false;
current_crc_type = CRC_NONE;
@ -185,6 +188,9 @@ void compute_crc(CrcType_t ct, const uint8_t *d, size_t n, uint8_t *first, uint8
case CRC_KERMIT:
crc = crc16_kermit(d, n);
break;
case CRC_11784:
crc = crc16_fdx(d, n);
break;
case CRC_LEGIC:
// TODO
return;
@ -215,6 +221,8 @@ uint16_t Crc16ex(CrcType_t ct, const uint8_t *d, size_t n) {
return crc16_ccitt(d, n);
case CRC_KERMIT:
return crc16_kermit(d, n);
case CRC_11784:
return crc16_fdx(d, n);
case CRC_LEGIC:
// TODO
return 0;
@ -257,6 +265,8 @@ bool check_crc(CrcType_t ct, const uint8_t *d, size_t n) {
return (crc16_ccitt(d, n) == 0);
case CRC_KERMIT:
return (crc16_kermit(d, n) == 0);
case CRC_11784:
return (crc16_fdx(d, n) == 0);
case CRC_LEGIC:
// TODO
return false;
@ -272,7 +282,12 @@ uint16_t crc16_ccitt(uint8_t const *d, size_t n) {
return crc16_fast(d, n, 0xffff, false, false);
}
// FDX-B ISO11784/85) uses KERMIT
// FDX-B ISO11784/85) uses KERMIT/CCITT
// poly 0x xx init=0x000 refin=false refout=true xorout=0x0000 ...
uint16_t crc16_fdx(uint8_t const *d, size_t n) {
return crc16_fast(d, n, 0x0000, false, true);
}
// poly=0x1021 init=0x0000 refin=true refout=true xorout=0x0000 name="KERMIT"
uint16_t crc16_kermit(uint8_t const *d, size_t n) {
return crc16_fast(d, n, 0x0000, true, true);