zephyr/drivers/crc/crc16_sw.c
Kumar Gala ccad5bf3e3 drivers: convert to using newly introduced integer sized types
Convert code to use u{8,16,32,64}_t and s{8,16,32,64}_t instead of C99
integer types.

Jira: ZEP-2051

Change-Id: I08f51e2bfd475f6245771c1bd2df7ffc744c48c4
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2017-04-21 10:06:48 -05:00

35 lines
608 B
C

/*
* Copyright (c) 2017 Intel Corporation.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <crc16.h>
u16_t crc16(const u8_t *src, size_t len, u16_t polynomial,
u16_t initial_value)
{
u16_t crc = initial_value;
size_t i, b;
/* src length + crc width of zeros appended */
for (i = 0; i < len + sizeof(crc); i++) {
for (b = 0; b < 8; b++) {
u16_t divide = crc & 0x8000;
crc = (crc << 1);
/* choose input bytes or implicit trailing zeros */
if (i < len) {
crc |= !!(src[i] & (0x80 >> b));
}
if (divide) {
crc = crc ^ polynomial;
}
}
}
return crc;
}