CRC-8 Checksum (crc8)

CRC-8 cyclic redundancy check, using the CRC-8/SMBUS algorithm standard. Chainable by feeding the previous CRC output as the initial value.

Algorithm Parameters

Parameter	Value
Name	CRC-8/SMBUS
Polynomial	0x07 (x⁸ + x² + x + 1)
Init	0x00
RefIn	False
RefOut	False
XorOut	0x00
Check	"123456789" → 0xF4

API

uint8_t crc8_sum(uint8_t crc, const uint8_t * buf, int len);

• crc — Initial value (typically 0 for the first call)
• buf — Data buffer
• len — Data length

Returns the CRC-8 checksum.

Example

Single Checksum

uint8_t msg[] = { 'x', 'b', 'o', 'o', 't' };
uint8_t checksum = crc8_sum(0, msg, sizeof(msg));
/* checksum = 0x01 */

Chained Calls

uint8_t part1[] = { 0x01, 0x02 };
uint8_t part2[] = { 0x03, 0x04 };
uint8_t crc = crc8_sum(0, part1, sizeof(part1));
crc = crc8_sum(crc, part2, sizeof(part2));