Common library for all Osmocom projects (libosmocore, libosmogsm, libosmovty, libosmogb, libosmosim, libosmousb, ...) https://osmocom.org/projects/libosmocore
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libosmocore/src/coding/gsm0503_parity.c

132 lines
2.6 KiB

/*
* (C) 2013 by Andreas Eversberg <jolly@eversberg.eu>
* (C) 2016 by Tom Tsou <tom.tsou@ettus.com>
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdint.h>
#include <osmocom/core/crcgen.h>
#include <osmocom/coding/gsm0503_parity.h>
/*
* GSM (SACCH) parity (FIRE code)
*
* g(x) = (x^23 + 1)(x^17 + x^3 + 1)
* = x^40 + x^26 + x^23 + x^17 + x^3 + a1
*/
const struct osmo_crc64gen_code gsm0503_fire_crc40 = {
.bits = 40,
.poly = 0x0004820009ULL,
.init = 0x0000000000ULL,
.remainder = 0xffffffffffULL,
};
/*
* GSM PDTCH CS-2, CS-3, CS-4 parity
*
* g(x) = x^16 + x^12 + x^5 + 1
*/
const struct osmo_crc16gen_code gsm0503_cs234_crc16 = {
.bits = 16,
.poly = 0x1021,
.init = 0x0000,
.remainder = 0xffff,
};
/*
* EDGE MCS header parity
*
*/
const struct osmo_crc8gen_code gsm0503_mcs_crc8_hdr = {
.bits = 8,
.poly = 0x49,
.init = 0x00,
.remainder = 0xff,
};
/*
* EDGE MCS data parity
*
*/
const struct osmo_crc16gen_code gsm0503_mcs_crc12 = {
.bits = 12,
.poly = 0x0d31,
.init = 0x0000,
.remainder = 0x0fff,
};
/*
* GSM RACH parity
*
* g(x) = x^6 + x^5 + x^3 + x^2 + x^1 + 1
*/
const struct osmo_crc8gen_code gsm0503_rach_crc6 = {
.bits = 6,
.poly = 0x2f,
.init = 0x00,
.remainder = 0x3f,
};
/*
* GSM SCH parity
*
* g(x) = x^10 + x^8 + x^6 + x^5 + x^4 + x^2 + 1
*/
const struct osmo_crc16gen_code gsm0503_sch_crc10 = {
.bits = 10,
.poly = 0x175,
.init = 0x000,
.remainder = 0x3ff,
};
/*
* GSM TCH FR/HR/EFR parity
*
* g(x) = x^3 + x + 1
*/
const struct osmo_crc8gen_code gsm0503_tch_fr_crc3 = {
.bits = 3,
.poly = 0x3,
.init = 0x0,
.remainder = 0x7,
};
/*
* GSM TCH EFR parity
*
* g(x) = x^8 + x^4 + x^3 + x^2 + 1
*/
const struct osmo_crc8gen_code gsm0503_tch_efr_crc8 = {
.bits = 8,
.poly = 0x1d,
.init = 0x00,
.remainder = 0x00,
};
/*
* GSM AMR parity
*
* g(x) = x^6 + x^5 + x^3 + x^2 + x^1 + 1
*/
const struct osmo_crc8gen_code gsm0503_amr_crc6 = {
.bits = 6,
.poly = 0x2f,
.init = 0x00,
.remainder = 0x3f,
};