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Update Crc16 function to use bitlength instead of length

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douniwan5788 2025-03-15 04:18:41 +08:00
parent 6a671616b9
commit ff1289c03d
2 changed files with 10 additions and 5 deletions
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13
common/crc16.c
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@ -142,12 +142,17 @@ uint16_t update_crc16(uint16_t crc, uint8_t c) {
}
// two ways. msb or lsb loop.
uint16_t Crc16(uint8_t const *d, size_t length, uint16_t remainder, uint16_t polynomial, bool refin, bool refout) {
if (length == 0)
uint16_t Crc16(uint8_t const *d, size_t bitlength, uint16_t remainder, uint16_t polynomial, bool refin, bool refout) {
if (bitlength == 0)
return (~remainder);
for (uint32_t i = 0; i < length; ++i) {
uint8_t c = d[i];
uint8_t offset = 8 - (bitlength % 8);
// front padding with 0s won't change the CRC result
uint8_t prebits = 0;
for (uint32_t i = 0; i < (bitlength + 7) / 8; ++i) {
uint8_t c = prebits | d[i] >> offset;
prebits = d[i] << (8 - offset);
if (refin) c = reflect8(c);
// xor in at msb

2
common/crc16.h
View file

@ -47,7 +47,7 @@ typedef enum {
uint16_t update_crc16_ex(uint16_t crc, uint8_t c, uint16_t polynomial);
uint16_t update_crc16(uint16_t crc, uint8_t c);
uint16_t Crc16(uint8_t const *d, size_t length, uint16_t remainder, uint16_t polynomial, bool refin, bool refout);
uint16_t Crc16(uint8_t const *d, size_t bitlength, uint16_t remainder, uint16_t polynomial, bool refin, bool refout);
uint16_t Crc16ex(CrcType_t ct, const uint8_t *d, size_t n);
void compute_crc(CrcType_t ct, const uint8_t *d, size_t n, uint8_t *first, uint8_t *second);