/* This file is a modified version of the output of pycrc. * * Licensing terms of pycrc: * * Copyright (c) 2006-2007, Thomas Pircher * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. * * * crc7.c: Calculate CRC7 for SD card commands * */ /* * Functions and types for CRC checks. * * Generated on Thu Nov 8 13:52:05 2007, * by pycrc v0.6.3, http://www.tty1.net/pycrc/ * using the configuration: * Width = 7 * Poly = 0x09 * XorIn = 0x00 * ReflectIn = False * XorOut = 0x00 * ReflectOut = False * Algorithm = bit-by-bit-fast */ #include #include #include /** ; MMC/SD CRC Polynom X^7 + X^3 + 1 crc7taba: mov dptr,#CRC7_TABA ; (2) clr c ; (1) rrc a ; (1) xrl a,crc7ta ; (1) movc a,@a+dptr ; (2) jnc crc7m ; (2) xrl a,#00001001b ; (1) crc7m: mov crc7ta,a ; (1) ret ; (2) (LCALL=2) */ uint8_t crc7tab[128] = { 0x00,0x12,0x24,0x36,0x48,0x5a,0x6c,0x7e, 0x19,0x0b,0x3d,0x2f,0x51,0x43,0x75,0x67, 0x32,0x20,0x16,0x04,0x7a,0x68,0x5e,0x4c, 0x2b,0x39,0x0f,0x1d,0x63,0x71,0x47,0x55, 0x64,0x76,0x40,0x52,0x2c,0x3e,0x08,0x1a, 0x7d,0x6f,0x59,0x4b,0x35,0x27,0x11,0x03, 0x56,0x44,0x72,0x60,0x1e,0x0c,0x3a,0x28, 0x4f,0x5d,0x6b,0x79,0x07,0x15,0x23,0x31, 0x41,0x53,0x65,0x77,0x09,0x1b,0x2d,0x3f, 0x58,0x4a,0x7c,0x6e,0x10,0x02,0x34,0x26, 0x73,0x61,0x57,0x45,0x3b,0x29,0x1f,0x0d, 0x6a,0x78,0x4e,0x5c,0x22,0x30,0x06,0x14, 0x25,0x37,0x01,0x13,0x6d,0x7f,0x49,0x5b, 0x3c,0x2e,0x18,0x0a,0x74,0x66,0x50,0x42, 0x17,0x05,0x33,0x21,0x5f,0x4d,0x7b,0x69, 0x0e,0x1c,0x2a,0x38,0x46,0x54,0x62,0x70 }; uint8_t crc7update(uint8_t crc, const uint8_t data) { uint8_t a = data; uint8_t b = data & 1; a = crc7tab[(a>>1) ^ crc]; a ^= ((b<<3)|(b)); crc = a; return a; } /*uint8_t crc7update(uint8_t crc, const uint8_t data) { uint8_t i; bool bit; uint8_t c; c = data; for (i = 0x80; i > 0; i >>= 1) { bit = crc & 0x40; if (c & i) { bit = !bit; } crc <<= 1; if (bit) { crc ^= 0x09; } } crc &= 0x7f; return crc & 0x7f; }*/