unleashed-firmware/lib/one_wire/maxim_crc.c
SG bdba15b366
[FL-2393][FL-2381] iButton, OneWire: move to plain C (#1068)
* iButton: getting started on the worker concept
* Hal delay: added global instructions_per_us variable
* iButton: one wire slave
* iButton: ibutton key setter
* iButton: one wire host, use ibutton_hal
* iButton\RFID: common pulse decoder concept
* iButton: cyfral decoder
* iButton: worker thread concept
* iButton: metakom decoder
* iButton: write key through worker
* iButton: worker mode holder
* iButton: worker improvements
* iButton: Cyfral encoder
* iButton: Metakom encoder
* lib: pulse protocol helpers
* iButton: Metakom decoder
* iButton: Cyfral decoder
* iButton worker: separate modes
* iButton: libs documentation
* HAL: iButton gpio modes
* iButton worker: rename modes file
* iButton worker, hal: move to LL
* iButton CLI: worker for reading and emulation commands
* iButton HAL: correct init and emulation sequence
* iButton cli: moved to plain C
* iButton: move to worker, small step to plain C
* Libs, one wire: move to plain C
* Libs: added forgotten files to compilation
* iButton writer: get rid of manual disable/enable irq
2022-03-29 16:01:56 +03:00

16 lines
511 B
C

#include "maxim_crc.h"
uint8_t maxim_crc8(const uint8_t* data, const uint8_t data_size, const uint8_t crc_init) {
uint8_t crc = crc_init;
for(uint8_t index = 0; index < data_size; ++index) {
uint8_t input_byte = data[index];
for(uint8_t bit_position = 0; bit_position < 8; ++bit_position) {
const uint8_t mix = (crc ^ input_byte) & (uint8_t)(0x01);
crc >>= 1;
if(mix != 0) crc ^= 0x8C;
input_byte >>= 1;
}
}
return crc;
}