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mbed 2

This is the mbed 2 library. If you'd like to learn about Mbed OS please see the mbed-os docs.

drivers/MbedCRC.h@172:65be27845400, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 20:53:29 2019 +0000
Revision:
172:65be27845400
Parent:
171:3a7713b1edbc 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 165:d1b4690b3f8b 1 /* mbed Microcontroller Library
AnnaBridge 165:d1b4690b3f8b 2 * Copyright (c) 2018 ARM Limited
AnnaBridge 172:65be27845400 3 * SPDX-License-Identifier: Apache-2.0
AnnaBridge 165:d1b4690b3f8b 4 *
AnnaBridge 165:d1b4690b3f8b 5 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 165:d1b4690b3f8b 6 * you may not use this file except in compliance with the License.
AnnaBridge 165:d1b4690b3f8b 7 * You may obtain a copy of the License at
AnnaBridge 165:d1b4690b3f8b 8 *
AnnaBridge 165:d1b4690b3f8b 9 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 165:d1b4690b3f8b 10 *
AnnaBridge 165:d1b4690b3f8b 11 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 165:d1b4690b3f8b 12 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 165:d1b4690b3f8b 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 165:d1b4690b3f8b 14 * See the License for the specific language governing permissions and
AnnaBridge 165:d1b4690b3f8b 15 * limitations under the License.
AnnaBridge 165:d1b4690b3f8b 16 */
AnnaBridge 165:d1b4690b3f8b 17 #ifndef MBED_CRC_API_H
AnnaBridge 165:d1b4690b3f8b 18 #define MBED_CRC_API_H
AnnaBridge 165:d1b4690b3f8b 19
AnnaBridge 165:d1b4690b3f8b 20 #include "drivers/TableCRC.h"
Anna Bridge 169:a7c7b631e539 21 #include "hal/crc_api.h"
AnnaBridge 165:d1b4690b3f8b 22 #include "platform/mbed_assert.h"
AnnaBridge 171:3a7713b1edbc 23 #include "platform/SingletonPtr.h"
AnnaBridge 171:3a7713b1edbc 24 #include "platform/PlatformMutex.h"
AnnaBridge 165:d1b4690b3f8b 25
AnnaBridge 165:d1b4690b3f8b 26 /* This is invalid warning from the compiler for below section of code
AnnaBridge 165:d1b4690b3f8b 27 if ((width < 8) && (NULL == _crc_table)) {
AnnaBridge 165:d1b4690b3f8b 28 p_crc = (uint32_t)(p_crc << (8 - width));
AnnaBridge 165:d1b4690b3f8b 29 }
AnnaBridge 165:d1b4690b3f8b 30 Compiler warns of the shift operation with width as it is width=(std::uint8_t),
AnnaBridge 165:d1b4690b3f8b 31 but we check for ( width < 8) before performing shift, so it should not be an issue.
AnnaBridge 165:d1b4690b3f8b 32 */
AnnaBridge 165:d1b4690b3f8b 33 #if defined ( __CC_ARM )
AnnaBridge 165:d1b4690b3f8b 34 #pragma diag_suppress 62 // Shift count is negative
AnnaBridge 165:d1b4690b3f8b 35 #elif defined ( __GNUC__ )
AnnaBridge 165:d1b4690b3f8b 36 #pragma GCC diagnostic push
AnnaBridge 165:d1b4690b3f8b 37 #pragma GCC diagnostic ignored "-Wshift-count-negative"
AnnaBridge 170:e95d10626187 38 #elif defined (__ICCARM__)
AnnaBridge 170:e95d10626187 39 #pragma diag_suppress=Pe062 // Shift count is negative
AnnaBridge 165:d1b4690b3f8b 40 #endif
AnnaBridge 165:d1b4690b3f8b 41
AnnaBridge 165:d1b4690b3f8b 42 namespace mbed {
AnnaBridge 165:d1b4690b3f8b 43 /** \addtogroup drivers */
AnnaBridge 165:d1b4690b3f8b 44 /** @{*/
AnnaBridge 165:d1b4690b3f8b 45
AnnaBridge 165:d1b4690b3f8b 46 /** CRC object provides CRC generation through hardware/software
AnnaBridge 165:d1b4690b3f8b 47 *
AnnaBridge 165:d1b4690b3f8b 48 * ROM polynomial tables for supported polynomials (:: crc_polynomial_t) will be used for
AnnaBridge 165:d1b4690b3f8b 49 * software CRC computation, if ROM tables are not available then CRC is computed runtime
AnnaBridge 165:d1b4690b3f8b 50 * bit by bit for all data input.
AnnaBridge 171:3a7713b1edbc 51 * @note Synchronization level: Thread safe
AnnaBridge 165:d1b4690b3f8b 52 *
AnnaBridge 165:d1b4690b3f8b 53 * @tparam polynomial CRC polynomial value in hex
AnnaBridge 165:d1b4690b3f8b 54 * @tparam width CRC polynomial width
AnnaBridge 165:d1b4690b3f8b 55 *
AnnaBridge 165:d1b4690b3f8b 56 * Example: Compute CRC data
AnnaBridge 165:d1b4690b3f8b 57 * @code
AnnaBridge 165:d1b4690b3f8b 58 *
AnnaBridge 165:d1b4690b3f8b 59 * #include "mbed.h"
AnnaBridge 165:d1b4690b3f8b 60 *
AnnaBridge 165:d1b4690b3f8b 61 * int main() {
AnnaBridge 165:d1b4690b3f8b 62 * MbedCRC<POLY_32BIT_ANSI, 32> ct;
AnnaBridge 165:d1b4690b3f8b 63 *
AnnaBridge 165:d1b4690b3f8b 64 * char test[] = "123456789";
AnnaBridge 165:d1b4690b3f8b 65 * uint32_t crc = 0;
AnnaBridge 165:d1b4690b3f8b 66 *
AnnaBridge 165:d1b4690b3f8b 67 * printf("\nPolynomial = 0x%lx Width = %d \n", ct.get_polynomial(), ct.get_width());
AnnaBridge 165:d1b4690b3f8b 68 *
AnnaBridge 165:d1b4690b3f8b 69 * ct.compute((void *)test, strlen((const char*)test), &crc);
AnnaBridge 165:d1b4690b3f8b 70 *
AnnaBridge 165:d1b4690b3f8b 71 * printf("The CRC of data \"123456789\" is : 0x%lx\n", crc);
AnnaBridge 165:d1b4690b3f8b 72 * return 0;
AnnaBridge 165:d1b4690b3f8b 73 * }
AnnaBridge 165:d1b4690b3f8b 74 * @endcode
AnnaBridge 165:d1b4690b3f8b 75 * Example: Compute CRC with data available in parts
AnnaBridge 165:d1b4690b3f8b 76 * @code
AnnaBridge 165:d1b4690b3f8b 77 *
AnnaBridge 165:d1b4690b3f8b 78 * #include "mbed.h"
AnnaBridge 165:d1b4690b3f8b 79 * int main() {
AnnaBridge 165:d1b4690b3f8b 80 * MbedCRC<POLY_32BIT_ANSI, 32> ct;
AnnaBridge 165:d1b4690b3f8b 81 *
AnnaBridge 165:d1b4690b3f8b 82 * char test[] = "123456789";
AnnaBridge 165:d1b4690b3f8b 83 * uint32_t crc = 0;
AnnaBridge 165:d1b4690b3f8b 84 *
AnnaBridge 165:d1b4690b3f8b 85 * printf("\nPolynomial = 0x%lx Width = %d \n", ct.get_polynomial(), ct.get_width());
AnnaBridge 165:d1b4690b3f8b 86 * ct.compute_partial_start(&crc);
AnnaBridge 165:d1b4690b3f8b 87 * ct.compute_partial((void *)&test, 4, &crc);
AnnaBridge 165:d1b4690b3f8b 88 * ct.compute_partial((void *)&test[4], 5, &crc);
AnnaBridge 165:d1b4690b3f8b 89 * ct.compute_partial_stop(&crc);
AnnaBridge 165:d1b4690b3f8b 90 * printf("The CRC of data \"123456789\" is : 0x%lx\n", crc);
AnnaBridge 165:d1b4690b3f8b 91 * return 0;
AnnaBridge 165:d1b4690b3f8b 92 * }
AnnaBridge 165:d1b4690b3f8b 93 * @endcode
AnnaBridge 165:d1b4690b3f8b 94 * @ingroup drivers
AnnaBridge 165:d1b4690b3f8b 95 */
AnnaBridge 165:d1b4690b3f8b 96
AnnaBridge 171:3a7713b1edbc 97 extern SingletonPtr<PlatformMutex> mbed_crc_mutex;
AnnaBridge 171:3a7713b1edbc 98
AnnaBridge 170:e95d10626187 99 template <uint32_t polynomial = POLY_32BIT_ANSI, uint8_t width = 32>
AnnaBridge 170:e95d10626187 100 class MbedCRC {
Anna Bridge 169:a7c7b631e539 101
Anna Bridge 169:a7c7b631e539 102 public:
AnnaBridge 172:65be27845400 103 enum CrcMode {
AnnaBridge 172:65be27845400 104 #if DEVICE_CRC
AnnaBridge 171:3a7713b1edbc 105 HARDWARE = 0,
AnnaBridge 171:3a7713b1edbc 106 #endif
AnnaBridge 171:3a7713b1edbc 107 TABLE = 1,
AnnaBridge 171:3a7713b1edbc 108 BITWISE
AnnaBridge 171:3a7713b1edbc 109 };
AnnaBridge 171:3a7713b1edbc 110
AnnaBridge 165:d1b4690b3f8b 111 typedef uint64_t crc_data_size_t;
AnnaBridge 165:d1b4690b3f8b 112
AnnaBridge 165:d1b4690b3f8b 113 /** Lifetime of CRC object
AnnaBridge 165:d1b4690b3f8b 114 *
AnnaBridge 165:d1b4690b3f8b 115 * @param initial_xor Inital value/seed to Xor
AnnaBridge 165:d1b4690b3f8b 116 * @param final_xor Final Xor value
AnnaBridge 165:d1b4690b3f8b 117 * @param reflect_data
AnnaBridge 165:d1b4690b3f8b 118 * @param reflect_remainder
AnnaBridge 171:3a7713b1edbc 119 * @note Default constructor without any arguments is valid only for supported CRC polynomials. :: crc_polynomial_t
AnnaBridge 165:d1b4690b3f8b 120 * MbedCRC <POLY_7BIT_SD, 7> ct; --- Valid POLY_7BIT_SD
AnnaBridge 165:d1b4690b3f8b 121 * MbedCRC <0x1021, 16> ct; --- Valid POLY_16BIT_CCITT
AnnaBridge 165:d1b4690b3f8b 122 * MbedCRC <POLY_16BIT_CCITT, 32> ct; --- Invalid, compilation error
AnnaBridge 171:3a7713b1edbc 123 * MbedCRC <POLY_16BIT_CCITT, 32> ct (i,f,rd,rr) Constructor can be used for not supported polynomials
AnnaBridge 165:d1b4690b3f8b 124 * MbedCRC<POLY_16BIT_CCITT, 16> sd(0, 0, false, false); Constructor can also be used for supported
AnnaBridge 165:d1b4690b3f8b 125 * polynomials with different intial/final/reflect values
AnnaBridge 165:d1b4690b3f8b 126 *
AnnaBridge 165:d1b4690b3f8b 127 */
AnnaBridge 165:d1b4690b3f8b 128 MbedCRC(uint32_t initial_xor, uint32_t final_xor, bool reflect_data, bool reflect_remainder) :
AnnaBridge 170:e95d10626187 129 _initial_value(initial_xor), _final_xor(final_xor), _reflect_data(reflect_data),
AnnaBridge 171:3a7713b1edbc 130 _reflect_remainder(reflect_remainder)
AnnaBridge 165:d1b4690b3f8b 131 {
AnnaBridge 165:d1b4690b3f8b 132 mbed_crc_ctor();
AnnaBridge 165:d1b4690b3f8b 133 }
AnnaBridge 165:d1b4690b3f8b 134 MbedCRC();
AnnaBridge 165:d1b4690b3f8b 135 virtual ~MbedCRC()
AnnaBridge 165:d1b4690b3f8b 136 {
AnnaBridge 165:d1b4690b3f8b 137 // Do nothing
AnnaBridge 165:d1b4690b3f8b 138 }
AnnaBridge 165:d1b4690b3f8b 139
AnnaBridge 165:d1b4690b3f8b 140 /** Compute CRC for the data input
AnnaBridge 171:3a7713b1edbc 141 * Compute CRC performs the initialization, computation and collection of
AnnaBridge 171:3a7713b1edbc 142 * final CRC.
AnnaBridge 165:d1b4690b3f8b 143 *
AnnaBridge 165:d1b4690b3f8b 144 * @param buffer Data bytes
AnnaBridge 165:d1b4690b3f8b 145 * @param size Size of data
AnnaBridge 165:d1b4690b3f8b 146 * @param crc CRC is the output value
AnnaBridge 165:d1b4690b3f8b 147 * @return 0 on success, negative error code on failure
AnnaBridge 165:d1b4690b3f8b 148 */
AnnaBridge 165:d1b4690b3f8b 149 int32_t compute(void *buffer, crc_data_size_t size, uint32_t *crc)
AnnaBridge 165:d1b4690b3f8b 150 {
AnnaBridge 165:d1b4690b3f8b 151 MBED_ASSERT(crc != NULL);
AnnaBridge 171:3a7713b1edbc 152 int32_t status = 0;
AnnaBridge 171:3a7713b1edbc 153
AnnaBridge 171:3a7713b1edbc 154 status = compute_partial_start(crc);
AnnaBridge 171:3a7713b1edbc 155 if (0 != status) {
AnnaBridge 171:3a7713b1edbc 156 unlock();
AnnaBridge 165:d1b4690b3f8b 157 return status;
AnnaBridge 165:d1b4690b3f8b 158 }
AnnaBridge 171:3a7713b1edbc 159
AnnaBridge 171:3a7713b1edbc 160 status = compute_partial(buffer, size, crc);
AnnaBridge 171:3a7713b1edbc 161 if (0 != status) {
AnnaBridge 171:3a7713b1edbc 162 unlock();
AnnaBridge 165:d1b4690b3f8b 163 return status;
AnnaBridge 165:d1b4690b3f8b 164 }
AnnaBridge 171:3a7713b1edbc 165
AnnaBridge 171:3a7713b1edbc 166 status = compute_partial_stop(crc);
AnnaBridge 171:3a7713b1edbc 167 if (0 != status) {
AnnaBridge 172:65be27845400 168 *crc = 0;
AnnaBridge 165:d1b4690b3f8b 169 }
AnnaBridge 171:3a7713b1edbc 170
AnnaBridge 171:3a7713b1edbc 171 return status;
AnnaBridge 171:3a7713b1edbc 172
AnnaBridge 165:d1b4690b3f8b 173 }
AnnaBridge 165:d1b4690b3f8b 174
AnnaBridge 165:d1b4690b3f8b 175 /** Compute partial CRC for the data input.
AnnaBridge 165:d1b4690b3f8b 176 *
AnnaBridge 165:d1b4690b3f8b 177 * CRC data if not available fully, CRC can be computed in parts with available data.
AnnaBridge 171:3a7713b1edbc 178 *
AnnaBridge 171:3a7713b1edbc 179 * In case of hardware, intermediate values and states are saved by hardware. Mutex
AnnaBridge 171:3a7713b1edbc 180 * locking is used to serialize access to hardware CRC.
AnnaBridge 171:3a7713b1edbc 181 *
AnnaBridge 171:3a7713b1edbc 182 * In case of software CRC, previous CRC output should be passed as argument to the
AnnaBridge 171:3a7713b1edbc 183 * current compute_partial call. Please note the intermediate CRC value is maintained by
AnnaBridge 171:3a7713b1edbc 184 * application and not the driver.
AnnaBridge 171:3a7713b1edbc 185 *
AnnaBridge 171:3a7713b1edbc 186 * @pre: Call `compute_partial_start` to start the partial CRC calculation.
AnnaBridge 171:3a7713b1edbc 187 * @post: Call `compute_partial_stop` to get the final CRC value.
AnnaBridge 165:d1b4690b3f8b 188 *
AnnaBridge 165:d1b4690b3f8b 189 * @param buffer Data bytes
AnnaBridge 165:d1b4690b3f8b 190 * @param size Size of data
AnnaBridge 165:d1b4690b3f8b 191 * @param crc CRC value is intermediate CRC value filled by API.
AnnaBridge 165:d1b4690b3f8b 192 * @return 0 on success or a negative error code on failure
AnnaBridge 171:3a7713b1edbc 193 * @note: CRC as output in compute_partial is not final CRC value, call `compute_partial_stop`
AnnaBridge 165:d1b4690b3f8b 194 * to get final correct CRC value.
AnnaBridge 165:d1b4690b3f8b 195 */
AnnaBridge 165:d1b4690b3f8b 196 int32_t compute_partial(void *buffer, crc_data_size_t size, uint32_t *crc)
AnnaBridge 165:d1b4690b3f8b 197 {
AnnaBridge 171:3a7713b1edbc 198 int32_t status = 0;
AnnaBridge 171:3a7713b1edbc 199
AnnaBridge 170:e95d10626187 200 switch (_mode) {
AnnaBridge 172:65be27845400 201 #if DEVICE_CRC
AnnaBridge 171:3a7713b1edbc 202 case HARDWARE:
Anna Bridge 169:a7c7b631e539 203 hal_crc_compute_partial((uint8_t *)buffer, size);
Anna Bridge 169:a7c7b631e539 204 *crc = 0;
AnnaBridge 171:3a7713b1edbc 205 break;
AnnaBridge 171:3a7713b1edbc 206 #endif
Anna Bridge 169:a7c7b631e539 207 case TABLE:
AnnaBridge 171:3a7713b1edbc 208 status = table_compute_partial(buffer, size, crc);
AnnaBridge 171:3a7713b1edbc 209 break;
Anna Bridge 169:a7c7b631e539 210 case BITWISE:
AnnaBridge 171:3a7713b1edbc 211 status = bitwise_compute_partial(buffer, size, crc);
AnnaBridge 171:3a7713b1edbc 212 break;
AnnaBridge 171:3a7713b1edbc 213 default:
AnnaBridge 171:3a7713b1edbc 214 status = -1;
AnnaBridge 171:3a7713b1edbc 215 break;
AnnaBridge 165:d1b4690b3f8b 216 }
Anna Bridge 169:a7c7b631e539 217
AnnaBridge 171:3a7713b1edbc 218 return status;
AnnaBridge 165:d1b4690b3f8b 219 }
AnnaBridge 165:d1b4690b3f8b 220
AnnaBridge 171:3a7713b1edbc 221 /** Compute partial start, indicate start of partial computation.
AnnaBridge 165:d1b4690b3f8b 222 *
AnnaBridge 165:d1b4690b3f8b 223 * This API should be called before performing any partial computation
AnnaBridge 165:d1b4690b3f8b 224 * with compute_partial API.
AnnaBridge 165:d1b4690b3f8b 225 *
AnnaBridge 165:d1b4690b3f8b 226 * @param crc Initial CRC value set by the API
AnnaBridge 165:d1b4690b3f8b 227 * @return 0 on success or a negative in case of failure
AnnaBridge 165:d1b4690b3f8b 228 * @note: CRC is an out parameter and must be reused with compute_partial
AnnaBridge 171:3a7713b1edbc 229 * and `compute_partial_stop` without any modifications in application.
AnnaBridge 165:d1b4690b3f8b 230 */
AnnaBridge 165:d1b4690b3f8b 231 int32_t compute_partial_start(uint32_t *crc)
AnnaBridge 165:d1b4690b3f8b 232 {
AnnaBridge 165:d1b4690b3f8b 233 MBED_ASSERT(crc != NULL);
Anna Bridge 169:a7c7b631e539 234
AnnaBridge 172:65be27845400 235 #if DEVICE_CRC
Anna Bridge 169:a7c7b631e539 236 if (_mode == HARDWARE) {
AnnaBridge 171:3a7713b1edbc 237 lock();
Anna Bridge 169:a7c7b631e539 238 crc_mbed_config_t config;
Anna Bridge 169:a7c7b631e539 239 config.polynomial = polynomial;
Anna Bridge 169:a7c7b631e539 240 config.width = width;
Anna Bridge 169:a7c7b631e539 241 config.initial_xor = _initial_value;
Anna Bridge 169:a7c7b631e539 242 config.final_xor = _final_xor;
Anna Bridge 169:a7c7b631e539 243 config.reflect_in = _reflect_data;
Anna Bridge 169:a7c7b631e539 244 config.reflect_out = _reflect_remainder;
Anna Bridge 169:a7c7b631e539 245
Anna Bridge 169:a7c7b631e539 246 hal_crc_compute_partial_start(&config);
Anna Bridge 169:a7c7b631e539 247 }
AnnaBridge 171:3a7713b1edbc 248 #endif
Anna Bridge 169:a7c7b631e539 249
AnnaBridge 165:d1b4690b3f8b 250 *crc = _initial_value;
AnnaBridge 165:d1b4690b3f8b 251 return 0;
AnnaBridge 165:d1b4690b3f8b 252 }
AnnaBridge 165:d1b4690b3f8b 253
AnnaBridge 165:d1b4690b3f8b 254 /** Get the final CRC value of partial computation.
AnnaBridge 165:d1b4690b3f8b 255 *
AnnaBridge 165:d1b4690b3f8b 256 * CRC value available in partial computation is not correct CRC, as some
AnnaBridge 165:d1b4690b3f8b 257 * algorithms require remainder to be reflected and final value to be XORed
AnnaBridge 165:d1b4690b3f8b 258 * This API is used to perform final computation to get correct CRC value.
AnnaBridge 165:d1b4690b3f8b 259 *
AnnaBridge 165:d1b4690b3f8b 260 * @param crc CRC result
AnnaBridge 171:3a7713b1edbc 261 * @return 0 on success or a negative in case of failure.
AnnaBridge 165:d1b4690b3f8b 262 */
AnnaBridge 165:d1b4690b3f8b 263 int32_t compute_partial_stop(uint32_t *crc)
AnnaBridge 165:d1b4690b3f8b 264 {
AnnaBridge 165:d1b4690b3f8b 265 MBED_ASSERT(crc != NULL);
Anna Bridge 169:a7c7b631e539 266
AnnaBridge 172:65be27845400 267 #if DEVICE_CRC
Anna Bridge 169:a7c7b631e539 268 if (_mode == HARDWARE) {
Anna Bridge 169:a7c7b631e539 269 *crc = hal_crc_get_result();
AnnaBridge 171:3a7713b1edbc 270 unlock();
Anna Bridge 169:a7c7b631e539 271 return 0;
AnnaBridge 171:3a7713b1edbc 272 }
Anna Bridge 169:a7c7b631e539 273 #endif
AnnaBridge 165:d1b4690b3f8b 274 uint32_t p_crc = *crc;
AnnaBridge 165:d1b4690b3f8b 275 if ((width < 8) && (NULL == _crc_table)) {
AnnaBridge 165:d1b4690b3f8b 276 p_crc = (uint32_t)(p_crc << (8 - width));
AnnaBridge 165:d1b4690b3f8b 277 }
AnnaBridge 171:3a7713b1edbc 278 // Optimized algorithm for 32BitANSI does not need additional reflect_remainder
AnnaBridge 171:3a7713b1edbc 279 if ((TABLE == _mode) && (POLY_32BIT_REV_ANSI == polynomial)) {
AnnaBridge 171:3a7713b1edbc 280 *crc = (p_crc ^ _final_xor) & get_crc_mask();
AnnaBridge 171:3a7713b1edbc 281 } else {
AnnaBridge 171:3a7713b1edbc 282 *crc = (reflect_remainder(p_crc) ^ _final_xor) & get_crc_mask();
AnnaBridge 171:3a7713b1edbc 283 }
AnnaBridge 171:3a7713b1edbc 284 unlock();
AnnaBridge 165:d1b4690b3f8b 285 return 0;
AnnaBridge 165:d1b4690b3f8b 286 }
AnnaBridge 165:d1b4690b3f8b 287
AnnaBridge 171:3a7713b1edbc 288 /** Get the current CRC polynomial.
AnnaBridge 165:d1b4690b3f8b 289 *
AnnaBridge 165:d1b4690b3f8b 290 * @return Polynomial value
AnnaBridge 165:d1b4690b3f8b 291 */
AnnaBridge 165:d1b4690b3f8b 292 uint32_t get_polynomial(void) const
AnnaBridge 165:d1b4690b3f8b 293 {
AnnaBridge 165:d1b4690b3f8b 294 return polynomial;
AnnaBridge 165:d1b4690b3f8b 295 }
AnnaBridge 165:d1b4690b3f8b 296
AnnaBridge 165:d1b4690b3f8b 297 /** Get the current CRC width
AnnaBridge 165:d1b4690b3f8b 298 *
AnnaBridge 165:d1b4690b3f8b 299 * @return CRC width
AnnaBridge 165:d1b4690b3f8b 300 */
AnnaBridge 165:d1b4690b3f8b 301 uint8_t get_width(void) const
AnnaBridge 165:d1b4690b3f8b 302 {
AnnaBridge 165:d1b4690b3f8b 303 return width;
AnnaBridge 165:d1b4690b3f8b 304 }
AnnaBridge 165:d1b4690b3f8b 305
AnnaBridge 172:65be27845400 306 #if !defined(DOXYGEN_ONLY)
AnnaBridge 165:d1b4690b3f8b 307 private:
AnnaBridge 165:d1b4690b3f8b 308 uint32_t _initial_value;
AnnaBridge 165:d1b4690b3f8b 309 uint32_t _final_xor;
AnnaBridge 165:d1b4690b3f8b 310 bool _reflect_data;
AnnaBridge 165:d1b4690b3f8b 311 bool _reflect_remainder;
AnnaBridge 165:d1b4690b3f8b 312 uint32_t *_crc_table;
Anna Bridge 169:a7c7b631e539 313 CrcMode _mode;
AnnaBridge 165:d1b4690b3f8b 314
AnnaBridge 171:3a7713b1edbc 315 /** Acquire exclusive access to CRC hardware/software.
AnnaBridge 171:3a7713b1edbc 316 */
AnnaBridge 172:65be27845400 317 void lock()
AnnaBridge 171:3a7713b1edbc 318 {
AnnaBridge 172:65be27845400 319 #if DEVICE_CRC
AnnaBridge 171:3a7713b1edbc 320 if (_mode == HARDWARE) {
AnnaBridge 171:3a7713b1edbc 321 mbed_crc_mutex->lock();
AnnaBridge 171:3a7713b1edbc 322 }
AnnaBridge 171:3a7713b1edbc 323 #endif
AnnaBridge 171:3a7713b1edbc 324 }
AnnaBridge 171:3a7713b1edbc 325
AnnaBridge 171:3a7713b1edbc 326 /** Release exclusive access to CRC hardware/software.
AnnaBridge 171:3a7713b1edbc 327 */
AnnaBridge 171:3a7713b1edbc 328 virtual void unlock()
AnnaBridge 171:3a7713b1edbc 329 {
AnnaBridge 172:65be27845400 330 #if DEVICE_CRC
AnnaBridge 171:3a7713b1edbc 331 if (_mode == HARDWARE) {
AnnaBridge 171:3a7713b1edbc 332 mbed_crc_mutex->unlock();
AnnaBridge 171:3a7713b1edbc 333 }
AnnaBridge 171:3a7713b1edbc 334 #endif
AnnaBridge 171:3a7713b1edbc 335 }
AnnaBridge 171:3a7713b1edbc 336
AnnaBridge 171:3a7713b1edbc 337 /** Get the current CRC data size.
AnnaBridge 165:d1b4690b3f8b 338 *
AnnaBridge 165:d1b4690b3f8b 339 * @return CRC data size in bytes
AnnaBridge 165:d1b4690b3f8b 340 */
AnnaBridge 165:d1b4690b3f8b 341 uint8_t get_data_size(void) const
AnnaBridge 165:d1b4690b3f8b 342 {
AnnaBridge 165:d1b4690b3f8b 343 return (width <= 8 ? 1 : (width <= 16 ? 2 : 4));
AnnaBridge 165:d1b4690b3f8b 344 }
AnnaBridge 165:d1b4690b3f8b 345
AnnaBridge 171:3a7713b1edbc 346 /** Get the top bit of current CRC.
AnnaBridge 165:d1b4690b3f8b 347 *
AnnaBridge 165:d1b4690b3f8b 348 * @return Top bit is set high for respective data width of current CRC
AnnaBridge 165:d1b4690b3f8b 349 * Top bit for CRC width less then 8 bits will be set as 8th bit.
AnnaBridge 165:d1b4690b3f8b 350 */
AnnaBridge 165:d1b4690b3f8b 351 uint32_t get_top_bit(void) const
AnnaBridge 165:d1b4690b3f8b 352 {
AnnaBridge 165:d1b4690b3f8b 353 return (width < 8 ? (1u << 7) : (uint32_t)(1ul << (width - 1)));
AnnaBridge 165:d1b4690b3f8b 354 }
AnnaBridge 165:d1b4690b3f8b 355
AnnaBridge 171:3a7713b1edbc 356 /** Get the CRC data mask.
AnnaBridge 165:d1b4690b3f8b 357 *
AnnaBridge 165:d1b4690b3f8b 358 * @return CRC data mask is generated based on current CRC width
AnnaBridge 165:d1b4690b3f8b 359 */
AnnaBridge 165:d1b4690b3f8b 360 uint32_t get_crc_mask(void) const
AnnaBridge 165:d1b4690b3f8b 361 {
AnnaBridge 165:d1b4690b3f8b 362 return (width < 8 ? ((1u << 8) - 1) : (uint32_t)((uint64_t)(1ull << width) - 1));
AnnaBridge 165:d1b4690b3f8b 363 }
AnnaBridge 165:d1b4690b3f8b 364
AnnaBridge 171:3a7713b1edbc 365 /** Final value of CRC is reflected.
AnnaBridge 165:d1b4690b3f8b 366 *
AnnaBridge 165:d1b4690b3f8b 367 * @param data final crc value, which should be reflected
AnnaBridge 165:d1b4690b3f8b 368 * @return Reflected CRC value
AnnaBridge 165:d1b4690b3f8b 369 */
AnnaBridge 165:d1b4690b3f8b 370 uint32_t reflect_remainder(uint32_t data) const
AnnaBridge 165:d1b4690b3f8b 371 {
AnnaBridge 165:d1b4690b3f8b 372 if (_reflect_remainder) {
AnnaBridge 165:d1b4690b3f8b 373 uint32_t reflection = 0x0;
AnnaBridge 165:d1b4690b3f8b 374 uint8_t const nBits = (width < 8 ? 8 : width);
AnnaBridge 165:d1b4690b3f8b 375
AnnaBridge 165:d1b4690b3f8b 376 for (uint8_t bit = 0; bit < nBits; ++bit) {
AnnaBridge 165:d1b4690b3f8b 377 if (data & 0x01) {
AnnaBridge 165:d1b4690b3f8b 378 reflection |= (1 << ((nBits - 1) - bit));
AnnaBridge 165:d1b4690b3f8b 379 }
AnnaBridge 165:d1b4690b3f8b 380 data = (data >> 1);
AnnaBridge 165:d1b4690b3f8b 381 }
AnnaBridge 165:d1b4690b3f8b 382 return (reflection);
AnnaBridge 165:d1b4690b3f8b 383 } else {
AnnaBridge 165:d1b4690b3f8b 384 return data;
AnnaBridge 165:d1b4690b3f8b 385 }
AnnaBridge 165:d1b4690b3f8b 386 }
AnnaBridge 165:d1b4690b3f8b 387
AnnaBridge 171:3a7713b1edbc 388 /** Data bytes are reflected.
AnnaBridge 165:d1b4690b3f8b 389 *
AnnaBridge 165:d1b4690b3f8b 390 * @param data value to be reflected
AnnaBridge 165:d1b4690b3f8b 391 * @return Reflected data value
AnnaBridge 165:d1b4690b3f8b 392 */
AnnaBridge 165:d1b4690b3f8b 393 uint32_t reflect_bytes(uint32_t data) const
AnnaBridge 165:d1b4690b3f8b 394 {
AnnaBridge 170:e95d10626187 395 if (_reflect_data) {
AnnaBridge 165:d1b4690b3f8b 396 uint32_t reflection = 0x0;
AnnaBridge 165:d1b4690b3f8b 397
AnnaBridge 165:d1b4690b3f8b 398 for (uint8_t bit = 0; bit < 8; ++bit) {
AnnaBridge 165:d1b4690b3f8b 399 if (data & 0x01) {
AnnaBridge 165:d1b4690b3f8b 400 reflection |= (1 << (7 - bit));
AnnaBridge 165:d1b4690b3f8b 401 }
AnnaBridge 165:d1b4690b3f8b 402 data = (data >> 1);
AnnaBridge 165:d1b4690b3f8b 403 }
AnnaBridge 165:d1b4690b3f8b 404 return (reflection);
AnnaBridge 165:d1b4690b3f8b 405 } else {
AnnaBridge 165:d1b4690b3f8b 406 return data;
AnnaBridge 165:d1b4690b3f8b 407 }
AnnaBridge 165:d1b4690b3f8b 408 }
AnnaBridge 165:d1b4690b3f8b 409
AnnaBridge 171:3a7713b1edbc 410 /** Bitwise CRC computation.
AnnaBridge 165:d1b4690b3f8b 411 *
AnnaBridge 165:d1b4690b3f8b 412 * @param buffer data buffer
AnnaBridge 165:d1b4690b3f8b 413 * @param size size of the data
AnnaBridge 165:d1b4690b3f8b 414 * @param crc CRC value is filled in, but the value is not the final
AnnaBridge 165:d1b4690b3f8b 415 * @return 0 on success or a negative error code on failure
AnnaBridge 165:d1b4690b3f8b 416 */
AnnaBridge 165:d1b4690b3f8b 417 int32_t bitwise_compute_partial(const void *buffer, crc_data_size_t size, uint32_t *crc) const
AnnaBridge 165:d1b4690b3f8b 418 {
AnnaBridge 165:d1b4690b3f8b 419 MBED_ASSERT(crc != NULL);
AnnaBridge 165:d1b4690b3f8b 420
AnnaBridge 165:d1b4690b3f8b 421 const uint8_t *data = static_cast<const uint8_t *>(buffer);
AnnaBridge 165:d1b4690b3f8b 422 uint32_t p_crc = *crc;
AnnaBridge 165:d1b4690b3f8b 423
AnnaBridge 165:d1b4690b3f8b 424 if (width < 8) {
AnnaBridge 165:d1b4690b3f8b 425 uint8_t data_byte;
AnnaBridge 165:d1b4690b3f8b 426 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 165:d1b4690b3f8b 427 data_byte = reflect_bytes(data[byte]);
AnnaBridge 165:d1b4690b3f8b 428 for (uint8_t bit = 8; bit > 0; --bit) {
AnnaBridge 165:d1b4690b3f8b 429 p_crc <<= 1;
AnnaBridge 170:e95d10626187 430 if ((data_byte ^ p_crc) & get_top_bit()) {
AnnaBridge 165:d1b4690b3f8b 431 p_crc ^= polynomial;
AnnaBridge 165:d1b4690b3f8b 432 }
AnnaBridge 165:d1b4690b3f8b 433 data_byte <<= 1;
AnnaBridge 165:d1b4690b3f8b 434 }
AnnaBridge 165:d1b4690b3f8b 435 }
AnnaBridge 165:d1b4690b3f8b 436 } else {
AnnaBridge 165:d1b4690b3f8b 437 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 165:d1b4690b3f8b 438 p_crc ^= (reflect_bytes(data[byte]) << (width - 8));
AnnaBridge 165:d1b4690b3f8b 439
AnnaBridge 165:d1b4690b3f8b 440 // Perform modulo-2 division, a bit at a time
AnnaBridge 165:d1b4690b3f8b 441 for (uint8_t bit = 8; bit > 0; --bit) {
AnnaBridge 165:d1b4690b3f8b 442 if (p_crc & get_top_bit()) {
AnnaBridge 165:d1b4690b3f8b 443 p_crc = (p_crc << 1) ^ polynomial;
AnnaBridge 165:d1b4690b3f8b 444 } else {
AnnaBridge 165:d1b4690b3f8b 445 p_crc = (p_crc << 1);
AnnaBridge 165:d1b4690b3f8b 446 }
AnnaBridge 165:d1b4690b3f8b 447 }
AnnaBridge 165:d1b4690b3f8b 448 }
AnnaBridge 165:d1b4690b3f8b 449 }
AnnaBridge 165:d1b4690b3f8b 450 *crc = p_crc & get_crc_mask();
AnnaBridge 165:d1b4690b3f8b 451 return 0;
AnnaBridge 165:d1b4690b3f8b 452 }
AnnaBridge 165:d1b4690b3f8b 453
AnnaBridge 171:3a7713b1edbc 454 /** CRC computation using ROM tables.
AnnaBridge 170:e95d10626187 455 *
AnnaBridge 170:e95d10626187 456 * @param buffer data buffer
AnnaBridge 170:e95d10626187 457 * @param size size of the data
AnnaBridge 170:e95d10626187 458 * @param crc CRC value is filled in, but the value is not the final
AnnaBridge 170:e95d10626187 459 * @return 0 on success or a negative error code on failure
AnnaBridge 170:e95d10626187 460 */
AnnaBridge 165:d1b4690b3f8b 461 int32_t table_compute_partial(const void *buffer, crc_data_size_t size, uint32_t *crc) const
AnnaBridge 165:d1b4690b3f8b 462 {
AnnaBridge 165:d1b4690b3f8b 463 MBED_ASSERT(crc != NULL);
AnnaBridge 165:d1b4690b3f8b 464
AnnaBridge 165:d1b4690b3f8b 465 const uint8_t *data = static_cast<const uint8_t *>(buffer);
AnnaBridge 165:d1b4690b3f8b 466 uint32_t p_crc = *crc;
AnnaBridge 165:d1b4690b3f8b 467 uint8_t data_byte = 0;
AnnaBridge 165:d1b4690b3f8b 468
AnnaBridge 165:d1b4690b3f8b 469 if (width <= 8) {
AnnaBridge 165:d1b4690b3f8b 470 uint8_t *crc_table = (uint8_t *)_crc_table;
AnnaBridge 165:d1b4690b3f8b 471 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 165:d1b4690b3f8b 472 data_byte = reflect_bytes(data[byte]) ^ p_crc;
AnnaBridge 165:d1b4690b3f8b 473 p_crc = crc_table[data_byte];
AnnaBridge 165:d1b4690b3f8b 474 }
AnnaBridge 165:d1b4690b3f8b 475 } else if (width <= 16) {
AnnaBridge 165:d1b4690b3f8b 476 uint16_t *crc_table = (uint16_t *)_crc_table;
AnnaBridge 165:d1b4690b3f8b 477 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 165:d1b4690b3f8b 478 data_byte = reflect_bytes(data[byte]) ^ (p_crc >> (width - 8));
AnnaBridge 165:d1b4690b3f8b 479 p_crc = crc_table[data_byte] ^ (p_crc << 8);
AnnaBridge 165:d1b4690b3f8b 480 }
AnnaBridge 165:d1b4690b3f8b 481 } else {
AnnaBridge 165:d1b4690b3f8b 482 uint32_t *crc_table = (uint32_t *)_crc_table;
AnnaBridge 171:3a7713b1edbc 483 if (POLY_32BIT_REV_ANSI == polynomial) {
AnnaBridge 171:3a7713b1edbc 484 for (crc_data_size_t i = 0; i < size; i++) {
AnnaBridge 171:3a7713b1edbc 485 p_crc = (p_crc >> 4) ^ crc_table[(p_crc ^ (data[i] >> 0)) & 0xf];
AnnaBridge 171:3a7713b1edbc 486 p_crc = (p_crc >> 4) ^ crc_table[(p_crc ^ (data[i] >> 4)) & 0xf];
AnnaBridge 171:3a7713b1edbc 487 }
AnnaBridge 172:65be27845400 488 } else {
AnnaBridge 171:3a7713b1edbc 489 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 171:3a7713b1edbc 490 data_byte = reflect_bytes(data[byte]) ^ (p_crc >> (width - 8));
AnnaBridge 171:3a7713b1edbc 491 p_crc = crc_table[data_byte] ^ (p_crc << 8);
AnnaBridge 171:3a7713b1edbc 492 }
AnnaBridge 165:d1b4690b3f8b 493 }
AnnaBridge 165:d1b4690b3f8b 494 }
AnnaBridge 165:d1b4690b3f8b 495 *crc = p_crc & get_crc_mask();
AnnaBridge 165:d1b4690b3f8b 496 return 0;
AnnaBridge 165:d1b4690b3f8b 497 }
AnnaBridge 165:d1b4690b3f8b 498
AnnaBridge 171:3a7713b1edbc 499 /** Constructor init called from all specialized cases of constructor.
AnnaBridge 172:65be27845400 500 * Note: All constructor common code should be in this function.
AnnaBridge 165:d1b4690b3f8b 501 */
Anna Bridge 169:a7c7b631e539 502 void mbed_crc_ctor(void)
AnnaBridge 165:d1b4690b3f8b 503 {
AnnaBridge 165:d1b4690b3f8b 504 MBED_STATIC_ASSERT(width <= 32, "Max 32-bit CRC supported");
Anna Bridge 169:a7c7b631e539 505
AnnaBridge 172:65be27845400 506 #if DEVICE_CRC
AnnaBridge 171:3a7713b1edbc 507 if (POLY_32BIT_REV_ANSI == polynomial) {
AnnaBridge 171:3a7713b1edbc 508 _crc_table = (uint32_t *)Table_CRC_32bit_Rev_ANSI;
AnnaBridge 171:3a7713b1edbc 509 _mode = TABLE;
AnnaBridge 171:3a7713b1edbc 510 return;
AnnaBridge 171:3a7713b1edbc 511 }
Anna Bridge 169:a7c7b631e539 512 crc_mbed_config_t config;
Anna Bridge 169:a7c7b631e539 513 config.polynomial = polynomial;
Anna Bridge 169:a7c7b631e539 514 config.width = width;
Anna Bridge 169:a7c7b631e539 515 config.initial_xor = _initial_value;
Anna Bridge 169:a7c7b631e539 516 config.final_xor = _final_xor;
Anna Bridge 169:a7c7b631e539 517 config.reflect_in = _reflect_data;
Anna Bridge 169:a7c7b631e539 518 config.reflect_out = _reflect_remainder;
Anna Bridge 169:a7c7b631e539 519
Anna Bridge 169:a7c7b631e539 520 if (hal_crc_is_supported(&config)) {
Anna Bridge 169:a7c7b631e539 521 _mode = HARDWARE;
AnnaBridge 171:3a7713b1edbc 522 return;
Anna Bridge 169:a7c7b631e539 523 }
Anna Bridge 169:a7c7b631e539 524 #endif
AnnaBridge 171:3a7713b1edbc 525
AnnaBridge 171:3a7713b1edbc 526 switch (polynomial) {
AnnaBridge 171:3a7713b1edbc 527 case POLY_32BIT_ANSI:
AnnaBridge 171:3a7713b1edbc 528 _crc_table = (uint32_t *)Table_CRC_32bit_ANSI;
AnnaBridge 171:3a7713b1edbc 529 break;
AnnaBridge 171:3a7713b1edbc 530 case POLY_32BIT_REV_ANSI:
AnnaBridge 171:3a7713b1edbc 531 _crc_table = (uint32_t *)Table_CRC_32bit_Rev_ANSI;
AnnaBridge 171:3a7713b1edbc 532 break;
AnnaBridge 171:3a7713b1edbc 533 case POLY_8BIT_CCITT:
AnnaBridge 171:3a7713b1edbc 534 _crc_table = (uint32_t *)Table_CRC_8bit_CCITT;
AnnaBridge 171:3a7713b1edbc 535 break;
AnnaBridge 171:3a7713b1edbc 536 case POLY_7BIT_SD:
AnnaBridge 171:3a7713b1edbc 537 _crc_table = (uint32_t *)Table_CRC_7Bit_SD;
AnnaBridge 171:3a7713b1edbc 538 break;
AnnaBridge 171:3a7713b1edbc 539 case POLY_16BIT_CCITT:
AnnaBridge 171:3a7713b1edbc 540 _crc_table = (uint32_t *)Table_CRC_16bit_CCITT;
AnnaBridge 171:3a7713b1edbc 541 break;
AnnaBridge 171:3a7713b1edbc 542 case POLY_16BIT_IBM:
AnnaBridge 171:3a7713b1edbc 543 _crc_table = (uint32_t *)Table_CRC_16bit_IBM;
AnnaBridge 171:3a7713b1edbc 544 break;
AnnaBridge 171:3a7713b1edbc 545 default:
AnnaBridge 171:3a7713b1edbc 546 _crc_table = NULL;
AnnaBridge 171:3a7713b1edbc 547 break;
AnnaBridge 171:3a7713b1edbc 548 }
AnnaBridge 171:3a7713b1edbc 549 _mode = (_crc_table != NULL) ? TABLE : BITWISE;
AnnaBridge 165:d1b4690b3f8b 550 }
AnnaBridge 172:65be27845400 551 #endif
AnnaBridge 165:d1b4690b3f8b 552 };
AnnaBridge 165:d1b4690b3f8b 553
AnnaBridge 165:d1b4690b3f8b 554 #if defined ( __CC_ARM )
AnnaBridge 165:d1b4690b3f8b 555 #elif defined ( __GNUC__ )
AnnaBridge 165:d1b4690b3f8b 556 #pragma GCC diagnostic pop
AnnaBridge 170:e95d10626187 557 #elif defined (__ICCARM__)
AnnaBridge 165:d1b4690b3f8b 558 #endif
AnnaBridge 165:d1b4690b3f8b 559
AnnaBridge 165:d1b4690b3f8b 560 /** @}*/
AnnaBridge 165:d1b4690b3f8b 561 } // namespace mbed
AnnaBridge 165:d1b4690b3f8b 562
AnnaBridge 165:d1b4690b3f8b 563 #endif