| /* |
| * Copyright (c) 2017 Nordic Semiconductor ASA |
| * Copyright (c) 2015 Runtime Inc |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <sys/crc.h> |
| |
| static const u8_t crc8_ccitt_small_table[16] = { |
| 0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15, |
| 0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d |
| }; |
| |
| u8_t crc8_ccitt(u8_t val, const void *buf, size_t cnt) |
| { |
| int i; |
| const u8_t *p = buf; |
| |
| for (i = 0; i < cnt; i++) { |
| val ^= p[i]; |
| val = (val << 4) ^ crc8_ccitt_small_table[val >> 4]; |
| val = (val << 4) ^ crc8_ccitt_small_table[val >> 4]; |
| } |
| return val; |
| } |