Thomas Lyp / DevLibMemoryController

Initial commit

Dependencies:   FastPWM

mbed-dev-master/drivers/MbedCRC.h@0:bb348c97df44, 2020-09-16 (annotated)

Committer:
lypinator
Date:
Wed Sep 16 01:11:49 2020 +0000
Revision:
0:bb348c97df44
Added PWM

Who changed what in which revision?

UserRevisionLine numberNew contents of line
lypinator 0:bb348c97df44 1 /* mbed Microcontroller Library
lypinator 0:bb348c97df44 2 * Copyright (c) 2018 ARM Limited
lypinator 0:bb348c97df44 3 *
lypinator 0:bb348c97df44 4 * Licensed under the Apache License, Version 2.0 (the "License");
lypinator 0:bb348c97df44 5 * you may not use this file except in compliance with the License.
lypinator 0:bb348c97df44 6 * You may obtain a copy of the License at
lypinator 0:bb348c97df44 7 *
lypinator 0:bb348c97df44 8 * http://www.apache.org/licenses/LICENSE-2.0
lypinator 0:bb348c97df44 9 *
lypinator 0:bb348c97df44 10 * Unless required by applicable law or agreed to in writing, software
lypinator 0:bb348c97df44 11 * distributed under the License is distributed on an "AS IS" BASIS,
lypinator 0:bb348c97df44 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
lypinator 0:bb348c97df44 13 * See the License for the specific language governing permissions and
lypinator 0:bb348c97df44 14 * limitations under the License.
lypinator 0:bb348c97df44 15 */
lypinator 0:bb348c97df44 16 #ifndef MBED_CRC_API_H
lypinator 0:bb348c97df44 17 #define MBED_CRC_API_H
lypinator 0:bb348c97df44 18
lypinator 0:bb348c97df44 19 #include "drivers/TableCRC.h"
lypinator 0:bb348c97df44 20 #include "hal/crc_api.h"
lypinator 0:bb348c97df44 21 #include "platform/mbed_assert.h"
lypinator 0:bb348c97df44 22
lypinator 0:bb348c97df44 23 /* This is invalid warning from the compiler for below section of code
lypinator 0:bb348c97df44 24 if ((width < 8) && (NULL == _crc_table)) {
lypinator 0:bb348c97df44 25 p_crc = (uint32_t)(p_crc << (8 - width));
lypinator 0:bb348c97df44 26 }
lypinator 0:bb348c97df44 27 Compiler warns of the shift operation with width as it is width=(std::uint8_t),
lypinator 0:bb348c97df44 28 but we check for ( width < 8) before performing shift, so it should not be an issue.
lypinator 0:bb348c97df44 29 */
lypinator 0:bb348c97df44 30 #if defined ( __CC_ARM )
lypinator 0:bb348c97df44 31 #pragma diag_suppress 62 // Shift count is negative
lypinator 0:bb348c97df44 32 #elif defined ( __GNUC__ )
lypinator 0:bb348c97df44 33 #pragma GCC diagnostic push
lypinator 0:bb348c97df44 34 #pragma GCC diagnostic ignored "-Wshift-count-negative"
lypinator 0:bb348c97df44 35 #elif defined (__ICCARM__)
lypinator 0:bb348c97df44 36 #pragma diag_suppress=Pe062 // Shift count is negative
lypinator 0:bb348c97df44 37 #endif
lypinator 0:bb348c97df44 38
lypinator 0:bb348c97df44 39 namespace mbed {
lypinator 0:bb348c97df44 40 /** \addtogroup drivers */
lypinator 0:bb348c97df44 41 /** @{*/
lypinator 0:bb348c97df44 42
lypinator 0:bb348c97df44 43 /** CRC object provides CRC generation through hardware/software
lypinator 0:bb348c97df44 44 *
lypinator 0:bb348c97df44 45 * ROM polynomial tables for supported polynomials (:: crc_polynomial_t) will be used for
lypinator 0:bb348c97df44 46 * software CRC computation, if ROM tables are not available then CRC is computed runtime
lypinator 0:bb348c97df44 47 * bit by bit for all data input.
lypinator 0:bb348c97df44 48 *
lypinator 0:bb348c97df44 49 * @tparam polynomial CRC polynomial value in hex
lypinator 0:bb348c97df44 50 * @tparam width CRC polynomial width
lypinator 0:bb348c97df44 51 *
lypinator 0:bb348c97df44 52 * Example: Compute CRC data
lypinator 0:bb348c97df44 53 * @code
lypinator 0:bb348c97df44 54 *
lypinator 0:bb348c97df44 55 * #include "mbed.h"
lypinator 0:bb348c97df44 56 *
lypinator 0:bb348c97df44 57 * int main() {
lypinator 0:bb348c97df44 58 * MbedCRC<POLY_32BIT_ANSI, 32> ct;
lypinator 0:bb348c97df44 59 *
lypinator 0:bb348c97df44 60 * char test[] = "123456789";
lypinator 0:bb348c97df44 61 * uint32_t crc = 0;
lypinator 0:bb348c97df44 62 *
lypinator 0:bb348c97df44 63 * printf("\nPolynomial = 0x%lx Width = %d \n", ct.get_polynomial(), ct.get_width());
lypinator 0:bb348c97df44 64 *
lypinator 0:bb348c97df44 65 * ct.compute((void *)test, strlen((const char*)test), &crc);
lypinator 0:bb348c97df44 66 *
lypinator 0:bb348c97df44 67 * printf("The CRC of data \"123456789\" is : 0x%lx\n", crc);
lypinator 0:bb348c97df44 68 * return 0;
lypinator 0:bb348c97df44 69 * }
lypinator 0:bb348c97df44 70 * @endcode
lypinator 0:bb348c97df44 71 * Example: Compute CRC with data available in parts
lypinator 0:bb348c97df44 72 * @code
lypinator 0:bb348c97df44 73 *
lypinator 0:bb348c97df44 74 * #include "mbed.h"
lypinator 0:bb348c97df44 75 * int main() {
lypinator 0:bb348c97df44 76 * MbedCRC<POLY_32BIT_ANSI, 32> ct;
lypinator 0:bb348c97df44 77 *
lypinator 0:bb348c97df44 78 * char test[] = "123456789";
lypinator 0:bb348c97df44 79 * uint32_t crc = 0;
lypinator 0:bb348c97df44 80 *
lypinator 0:bb348c97df44 81 * printf("\nPolynomial = 0x%lx Width = %d \n", ct.get_polynomial(), ct.get_width());
lypinator 0:bb348c97df44 82 *
lypinator 0:bb348c97df44 83 * ct.compute_partial_start(&crc);
lypinator 0:bb348c97df44 84 * ct.compute_partial((void *)&test, 4, &crc);
lypinator 0:bb348c97df44 85 * ct.compute_partial((void *)&test[4], 5, &crc);
lypinator 0:bb348c97df44 86 * ct.compute_partial_stop(&crc);
lypinator 0:bb348c97df44 87 *
lypinator 0:bb348c97df44 88 * printf("The CRC of data \"123456789\" is : 0x%lx\n", crc);
lypinator 0:bb348c97df44 89 * return 0;
lypinator 0:bb348c97df44 90 * }
lypinator 0:bb348c97df44 91 * @endcode
lypinator 0:bb348c97df44 92 * @ingroup drivers
lypinator 0:bb348c97df44 93 */
lypinator 0:bb348c97df44 94
lypinator 0:bb348c97df44 95 template <uint32_t polynomial = POLY_32BIT_ANSI, uint8_t width = 32>
lypinator 0:bb348c97df44 96 class MbedCRC {
lypinator 0:bb348c97df44 97 public:
lypinator 0:bb348c97df44 98 enum CrcMode { HARDWARE = 0, TABLE, BITWISE };
lypinator 0:bb348c97df44 99
lypinator 0:bb348c97df44 100 public:
lypinator 0:bb348c97df44 101 typedef uint64_t crc_data_size_t;
lypinator 0:bb348c97df44 102
lypinator 0:bb348c97df44 103 /** Lifetime of CRC object
lypinator 0:bb348c97df44 104 *
lypinator 0:bb348c97df44 105 * @param initial_xor Inital value/seed to Xor
lypinator 0:bb348c97df44 106 * @param final_xor Final Xor value
lypinator 0:bb348c97df44 107 * @param reflect_data
lypinator 0:bb348c97df44 108 * @param reflect_remainder
lypinator 0:bb348c97df44 109 * @note Default constructor without any arguments is valid only for supported CRC polynomials. :: crc_polynomial_t
lypinator 0:bb348c97df44 110 * MbedCRC <POLY_7BIT_SD, 7> ct; --- Valid POLY_7BIT_SD
lypinator 0:bb348c97df44 111 * MbedCRC <0x1021, 16> ct; --- Valid POLY_16BIT_CCITT
lypinator 0:bb348c97df44 112 * MbedCRC <POLY_16BIT_CCITT, 32> ct; --- Invalid, compilation error
lypinator 0:bb348c97df44 113 * MbedCRC <POLY_16BIT_CCITT, 32> ct (i,f,rd,rr) Consturctor can be used for not supported polynomials
lypinator 0:bb348c97df44 114 * MbedCRC<POLY_16BIT_CCITT, 16> sd(0, 0, false, false); Constructor can also be used for supported
lypinator 0:bb348c97df44 115 * polynomials with different intial/final/reflect values
lypinator 0:bb348c97df44 116 *
lypinator 0:bb348c97df44 117 */
lypinator 0:bb348c97df44 118 MbedCRC(uint32_t initial_xor, uint32_t final_xor, bool reflect_data, bool reflect_remainder) :
lypinator 0:bb348c97df44 119 _initial_value(initial_xor), _final_xor(final_xor), _reflect_data(reflect_data),
lypinator 0:bb348c97df44 120 _reflect_remainder(reflect_remainder), _crc_table(NULL)
lypinator 0:bb348c97df44 121 {
lypinator 0:bb348c97df44 122 mbed_crc_ctor();
lypinator 0:bb348c97df44 123 }
lypinator 0:bb348c97df44 124 MbedCRC();
lypinator 0:bb348c97df44 125 virtual ~MbedCRC()
lypinator 0:bb348c97df44 126 {
lypinator 0:bb348c97df44 127 // Do nothing
lypinator 0:bb348c97df44 128 }
lypinator 0:bb348c97df44 129
lypinator 0:bb348c97df44 130 /** Compute CRC for the data input
lypinator 0:bb348c97df44 131 *
lypinator 0:bb348c97df44 132 * @param buffer Data bytes
lypinator 0:bb348c97df44 133 * @param size Size of data
lypinator 0:bb348c97df44 134 * @param crc CRC is the output value
lypinator 0:bb348c97df44 135 * @return 0 on success, negative error code on failure
lypinator 0:bb348c97df44 136 */
lypinator 0:bb348c97df44 137 int32_t compute(void *buffer, crc_data_size_t size, uint32_t *crc)
lypinator 0:bb348c97df44 138 {
lypinator 0:bb348c97df44 139 MBED_ASSERT(crc != NULL);
lypinator 0:bb348c97df44 140 int32_t status;
lypinator 0:bb348c97df44 141 if (0 != (status = compute_partial_start(crc))) {
lypinator 0:bb348c97df44 142 *crc = 0;
lypinator 0:bb348c97df44 143 return status;
lypinator 0:bb348c97df44 144 }
lypinator 0:bb348c97df44 145 if (0 != (status = compute_partial(buffer, size, crc))) {
lypinator 0:bb348c97df44 146 *crc = 0;
lypinator 0:bb348c97df44 147 return status;
lypinator 0:bb348c97df44 148 }
lypinator 0:bb348c97df44 149 if (0 != (status = compute_partial_stop(crc))) {
lypinator 0:bb348c97df44 150 *crc = 0;
lypinator 0:bb348c97df44 151 return status;
lypinator 0:bb348c97df44 152 }
lypinator 0:bb348c97df44 153 return 0;
lypinator 0:bb348c97df44 154 }
lypinator 0:bb348c97df44 155
lypinator 0:bb348c97df44 156 /** Compute partial CRC for the data input.
lypinator 0:bb348c97df44 157 *
lypinator 0:bb348c97df44 158 * CRC data if not available fully, CRC can be computed in parts with available data.
lypinator 0:bb348c97df44 159 * Previous CRC output should be passed as argument to the current compute_partial call.
lypinator 0:bb348c97df44 160 * @pre: Call \ref compute_partial_start to start the partial CRC calculation.
lypinator 0:bb348c97df44 161 * @post: Call \ref compute_partial_stop to get the final CRC value.
lypinator 0:bb348c97df44 162 *
lypinator 0:bb348c97df44 163 * @param buffer Data bytes
lypinator 0:bb348c97df44 164 * @param size Size of data
lypinator 0:bb348c97df44 165 * @param crc CRC value is intermediate CRC value filled by API.
lypinator 0:bb348c97df44 166 * @return 0 on success or a negative error code on failure
lypinator 0:bb348c97df44 167 * @note: CRC as output in compute_partial is not final CRC value, call @ref compute_partial_stop
lypinator 0:bb348c97df44 168 * to get final correct CRC value.
lypinator 0:bb348c97df44 169 */
lypinator 0:bb348c97df44 170 int32_t compute_partial(void *buffer, crc_data_size_t size, uint32_t *crc)
lypinator 0:bb348c97df44 171 {
lypinator 0:bb348c97df44 172 switch (_mode) {
lypinator 0:bb348c97df44 173 case HARDWARE:
lypinator 0:bb348c97df44 174 #ifdef DEVICE_CRC
lypinator 0:bb348c97df44 175 hal_crc_compute_partial((uint8_t *)buffer, size);
lypinator 0:bb348c97df44 176 #endif // DEVICE_CRC
lypinator 0:bb348c97df44 177 *crc = 0;
lypinator 0:bb348c97df44 178 return 0;
lypinator 0:bb348c97df44 179 case TABLE:
lypinator 0:bb348c97df44 180 return table_compute_partial(buffer, size, crc);
lypinator 0:bb348c97df44 181 case BITWISE:
lypinator 0:bb348c97df44 182 return bitwise_compute_partial(buffer, size, crc);
lypinator 0:bb348c97df44 183 }
lypinator 0:bb348c97df44 184
lypinator 0:bb348c97df44 185 return -1;
lypinator 0:bb348c97df44 186 }
lypinator 0:bb348c97df44 187
lypinator 0:bb348c97df44 188 /** Compute partial start, indicate start of partial computation
lypinator 0:bb348c97df44 189 *
lypinator 0:bb348c97df44 190 * This API should be called before performing any partial computation
lypinator 0:bb348c97df44 191 * with compute_partial API.
lypinator 0:bb348c97df44 192 *
lypinator 0:bb348c97df44 193 * @param crc Initial CRC value set by the API
lypinator 0:bb348c97df44 194 * @return 0 on success or a negative in case of failure
lypinator 0:bb348c97df44 195 * @note: CRC is an out parameter and must be reused with compute_partial
lypinator 0:bb348c97df44 196 * and compute_partial_stop without any modifications in application.
lypinator 0:bb348c97df44 197 */
lypinator 0:bb348c97df44 198 int32_t compute_partial_start(uint32_t *crc)
lypinator 0:bb348c97df44 199 {
lypinator 0:bb348c97df44 200 MBED_ASSERT(crc != NULL);
lypinator 0:bb348c97df44 201
lypinator 0:bb348c97df44 202 #ifdef DEVICE_CRC
lypinator 0:bb348c97df44 203 if (_mode == HARDWARE) {
lypinator 0:bb348c97df44 204 crc_mbed_config_t config;
lypinator 0:bb348c97df44 205 config.polynomial = polynomial;
lypinator 0:bb348c97df44 206 config.width = width;
lypinator 0:bb348c97df44 207 config.initial_xor = _initial_value;
lypinator 0:bb348c97df44 208 config.final_xor = _final_xor;
lypinator 0:bb348c97df44 209 config.reflect_in = _reflect_data;
lypinator 0:bb348c97df44 210 config.reflect_out = _reflect_remainder;
lypinator 0:bb348c97df44 211
lypinator 0:bb348c97df44 212 hal_crc_compute_partial_start(&config);
lypinator 0:bb348c97df44 213 }
lypinator 0:bb348c97df44 214 #endif // DEVICE_CRC
lypinator 0:bb348c97df44 215
lypinator 0:bb348c97df44 216 *crc = _initial_value;
lypinator 0:bb348c97df44 217 return 0;
lypinator 0:bb348c97df44 218 }
lypinator 0:bb348c97df44 219
lypinator 0:bb348c97df44 220 /** Get the final CRC value of partial computation.
lypinator 0:bb348c97df44 221 *
lypinator 0:bb348c97df44 222 * CRC value available in partial computation is not correct CRC, as some
lypinator 0:bb348c97df44 223 * algorithms require remainder to be reflected and final value to be XORed
lypinator 0:bb348c97df44 224 * This API is used to perform final computation to get correct CRC value.
lypinator 0:bb348c97df44 225 *
lypinator 0:bb348c97df44 226 * @param crc CRC result
lypinator 0:bb348c97df44 227 */
lypinator 0:bb348c97df44 228 int32_t compute_partial_stop(uint32_t *crc)
lypinator 0:bb348c97df44 229 {
lypinator 0:bb348c97df44 230 MBED_ASSERT(crc != NULL);
lypinator 0:bb348c97df44 231
lypinator 0:bb348c97df44 232 if (_mode == HARDWARE) {
lypinator 0:bb348c97df44 233 #ifdef DEVICE_CRC
lypinator 0:bb348c97df44 234 *crc = hal_crc_get_result();
lypinator 0:bb348c97df44 235 return 0;
lypinator 0:bb348c97df44 236 #else
lypinator 0:bb348c97df44 237 return -1;
lypinator 0:bb348c97df44 238 #endif
lypinator 0:bb348c97df44 239 }
lypinator 0:bb348c97df44 240
lypinator 0:bb348c97df44 241 uint32_t p_crc = *crc;
lypinator 0:bb348c97df44 242 if ((width < 8) && (NULL == _crc_table)) {
lypinator 0:bb348c97df44 243 p_crc = (uint32_t)(p_crc << (8 - width));
lypinator 0:bb348c97df44 244 }
lypinator 0:bb348c97df44 245 *crc = (reflect_remainder(p_crc) ^ _final_xor) & get_crc_mask();
lypinator 0:bb348c97df44 246 return 0;
lypinator 0:bb348c97df44 247 }
lypinator 0:bb348c97df44 248
lypinator 0:bb348c97df44 249 /** Get the current CRC polynomial
lypinator 0:bb348c97df44 250 *
lypinator 0:bb348c97df44 251 * @return Polynomial value
lypinator 0:bb348c97df44 252 */
lypinator 0:bb348c97df44 253 uint32_t get_polynomial(void) const
lypinator 0:bb348c97df44 254 {
lypinator 0:bb348c97df44 255 return polynomial;
lypinator 0:bb348c97df44 256 }
lypinator 0:bb348c97df44 257
lypinator 0:bb348c97df44 258 /** Get the current CRC width
lypinator 0:bb348c97df44 259 *
lypinator 0:bb348c97df44 260 * @return CRC width
lypinator 0:bb348c97df44 261 */
lypinator 0:bb348c97df44 262 uint8_t get_width(void) const
lypinator 0:bb348c97df44 263 {
lypinator 0:bb348c97df44 264 return width;
lypinator 0:bb348c97df44 265 }
lypinator 0:bb348c97df44 266
lypinator 0:bb348c97df44 267 private:
lypinator 0:bb348c97df44 268 uint32_t _initial_value;
lypinator 0:bb348c97df44 269 uint32_t _final_xor;
lypinator 0:bb348c97df44 270 bool _reflect_data;
lypinator 0:bb348c97df44 271 bool _reflect_remainder;
lypinator 0:bb348c97df44 272 uint32_t *_crc_table;
lypinator 0:bb348c97df44 273 CrcMode _mode;
lypinator 0:bb348c97df44 274
lypinator 0:bb348c97df44 275 /** Get the current CRC data size
lypinator 0:bb348c97df44 276 *
lypinator 0:bb348c97df44 277 * @return CRC data size in bytes
lypinator 0:bb348c97df44 278 */
lypinator 0:bb348c97df44 279 uint8_t get_data_size(void) const
lypinator 0:bb348c97df44 280 {
lypinator 0:bb348c97df44 281 return (width <= 8 ? 1 : (width <= 16 ? 2 : 4));
lypinator 0:bb348c97df44 282 }
lypinator 0:bb348c97df44 283
lypinator 0:bb348c97df44 284 /** Get the top bit of current CRC
lypinator 0:bb348c97df44 285 *
lypinator 0:bb348c97df44 286 * @return Top bit is set high for respective data width of current CRC
lypinator 0:bb348c97df44 287 * Top bit for CRC width less then 8 bits will be set as 8th bit.
lypinator 0:bb348c97df44 288 */
lypinator 0:bb348c97df44 289 uint32_t get_top_bit(void) const
lypinator 0:bb348c97df44 290 {
lypinator 0:bb348c97df44 291 return (width < 8 ? (1u << 7) : (uint32_t)(1ul << (width - 1)));
lypinator 0:bb348c97df44 292 }
lypinator 0:bb348c97df44 293
lypinator 0:bb348c97df44 294 /** Get the CRC data mask
lypinator 0:bb348c97df44 295 *
lypinator 0:bb348c97df44 296 * @return CRC data mask is generated based on current CRC width
lypinator 0:bb348c97df44 297 */
lypinator 0:bb348c97df44 298 uint32_t get_crc_mask(void) const
lypinator 0:bb348c97df44 299 {
lypinator 0:bb348c97df44 300 return (width < 8 ? ((1u << 8) - 1) : (uint32_t)((uint64_t)(1ull << width) - 1));
lypinator 0:bb348c97df44 301 }
lypinator 0:bb348c97df44 302
lypinator 0:bb348c97df44 303 /** Final value of CRC is reflected
lypinator 0:bb348c97df44 304 *
lypinator 0:bb348c97df44 305 * @param data final crc value, which should be reflected
lypinator 0:bb348c97df44 306 * @return Reflected CRC value
lypinator 0:bb348c97df44 307 */
lypinator 0:bb348c97df44 308 uint32_t reflect_remainder(uint32_t data) const
lypinator 0:bb348c97df44 309 {
lypinator 0:bb348c97df44 310 if (_reflect_remainder) {
lypinator 0:bb348c97df44 311 uint32_t reflection = 0x0;
lypinator 0:bb348c97df44 312 uint8_t const nBits = (width < 8 ? 8 : width);
lypinator 0:bb348c97df44 313
lypinator 0:bb348c97df44 314 for (uint8_t bit = 0; bit < nBits; ++bit) {
lypinator 0:bb348c97df44 315 if (data & 0x01) {
lypinator 0:bb348c97df44 316 reflection |= (1 << ((nBits - 1) - bit));
lypinator 0:bb348c97df44 317 }
lypinator 0:bb348c97df44 318 data = (data >> 1);
lypinator 0:bb348c97df44 319 }
lypinator 0:bb348c97df44 320 return (reflection);
lypinator 0:bb348c97df44 321 } else {
lypinator 0:bb348c97df44 322 return data;
lypinator 0:bb348c97df44 323 }
lypinator 0:bb348c97df44 324 }
lypinator 0:bb348c97df44 325
lypinator 0:bb348c97df44 326 /** Data bytes are reflected
lypinator 0:bb348c97df44 327 *
lypinator 0:bb348c97df44 328 * @param data value to be reflected
lypinator 0:bb348c97df44 329 * @return Reflected data value
lypinator 0:bb348c97df44 330 */
lypinator 0:bb348c97df44 331 uint32_t reflect_bytes(uint32_t data) const
lypinator 0:bb348c97df44 332 {
lypinator 0:bb348c97df44 333 if (_reflect_data) {
lypinator 0:bb348c97df44 334 uint32_t reflection = 0x0;
lypinator 0:bb348c97df44 335
lypinator 0:bb348c97df44 336 for (uint8_t bit = 0; bit < 8; ++bit) {
lypinator 0:bb348c97df44 337 if (data & 0x01) {
lypinator 0:bb348c97df44 338 reflection |= (1 << (7 - bit));
lypinator 0:bb348c97df44 339 }
lypinator 0:bb348c97df44 340 data = (data >> 1);
lypinator 0:bb348c97df44 341 }
lypinator 0:bb348c97df44 342 return (reflection);
lypinator 0:bb348c97df44 343 } else {
lypinator 0:bb348c97df44 344 return data;
lypinator 0:bb348c97df44 345 }
lypinator 0:bb348c97df44 346 }
lypinator 0:bb348c97df44 347
lypinator 0:bb348c97df44 348 /** Bitwise CRC computation
lypinator 0:bb348c97df44 349 *
lypinator 0:bb348c97df44 350 * @param buffer data buffer
lypinator 0:bb348c97df44 351 * @param size size of the data
lypinator 0:bb348c97df44 352 * @param crc CRC value is filled in, but the value is not the final
lypinator 0:bb348c97df44 353 * @return 0 on success or a negative error code on failure
lypinator 0:bb348c97df44 354 */
lypinator 0:bb348c97df44 355 int32_t bitwise_compute_partial(const void *buffer, crc_data_size_t size, uint32_t *crc) const
lypinator 0:bb348c97df44 356 {
lypinator 0:bb348c97df44 357 MBED_ASSERT(crc != NULL);
lypinator 0:bb348c97df44 358 MBED_ASSERT(buffer != NULL);
lypinator 0:bb348c97df44 359
lypinator 0:bb348c97df44 360 const uint8_t *data = static_cast<const uint8_t *>(buffer);
lypinator 0:bb348c97df44 361 uint32_t p_crc = *crc;
lypinator 0:bb348c97df44 362
lypinator 0:bb348c97df44 363 if (width < 8) {
lypinator 0:bb348c97df44 364 uint8_t data_byte;
lypinator 0:bb348c97df44 365 for (crc_data_size_t byte = 0; byte < size; byte++) {
lypinator 0:bb348c97df44 366 data_byte = reflect_bytes(data[byte]);
lypinator 0:bb348c97df44 367 for (uint8_t bit = 8; bit > 0; --bit) {
lypinator 0:bb348c97df44 368 p_crc <<= 1;
lypinator 0:bb348c97df44 369 if ((data_byte ^ p_crc) & get_top_bit()) {
lypinator 0:bb348c97df44 370 p_crc ^= polynomial;
lypinator 0:bb348c97df44 371 }
lypinator 0:bb348c97df44 372 data_byte <<= 1;
lypinator 0:bb348c97df44 373 }
lypinator 0:bb348c97df44 374 }
lypinator 0:bb348c97df44 375 } else {
lypinator 0:bb348c97df44 376 for (crc_data_size_t byte = 0; byte < size; byte++) {
lypinator 0:bb348c97df44 377 p_crc ^= (reflect_bytes(data[byte]) << (width - 8));
lypinator 0:bb348c97df44 378
lypinator 0:bb348c97df44 379 // Perform modulo-2 division, a bit at a time
lypinator 0:bb348c97df44 380 for (uint8_t bit = 8; bit > 0; --bit) {
lypinator 0:bb348c97df44 381 if (p_crc & get_top_bit()) {
lypinator 0:bb348c97df44 382 p_crc = (p_crc << 1) ^ polynomial;
lypinator 0:bb348c97df44 383 } else {
lypinator 0:bb348c97df44 384 p_crc = (p_crc << 1);
lypinator 0:bb348c97df44 385 }
lypinator 0:bb348c97df44 386 }
lypinator 0:bb348c97df44 387 }
lypinator 0:bb348c97df44 388 }
lypinator 0:bb348c97df44 389 *crc = p_crc & get_crc_mask();
lypinator 0:bb348c97df44 390 return 0;
lypinator 0:bb348c97df44 391 }
lypinator 0:bb348c97df44 392
lypinator 0:bb348c97df44 393 /** CRC computation using ROM tables
lypinator 0:bb348c97df44 394 *
lypinator 0:bb348c97df44 395 * @param buffer data buffer
lypinator 0:bb348c97df44 396 * @param size size of the data
lypinator 0:bb348c97df44 397 * @param crc CRC value is filled in, but the value is not the final
lypinator 0:bb348c97df44 398 * @return 0 on success or a negative error code on failure
lypinator 0:bb348c97df44 399 */
lypinator 0:bb348c97df44 400 int32_t table_compute_partial(const void *buffer, crc_data_size_t size, uint32_t *crc) const
lypinator 0:bb348c97df44 401 {
lypinator 0:bb348c97df44 402 MBED_ASSERT(crc != NULL);
lypinator 0:bb348c97df44 403 MBED_ASSERT(buffer != NULL);
lypinator 0:bb348c97df44 404
lypinator 0:bb348c97df44 405 const uint8_t *data = static_cast<const uint8_t *>(buffer);
lypinator 0:bb348c97df44 406 uint32_t p_crc = *crc;
lypinator 0:bb348c97df44 407 uint8_t data_byte = 0;
lypinator 0:bb348c97df44 408
lypinator 0:bb348c97df44 409 if (width <= 8) {
lypinator 0:bb348c97df44 410 uint8_t *crc_table = (uint8_t *)_crc_table;
lypinator 0:bb348c97df44 411 for (crc_data_size_t byte = 0; byte < size; byte++) {
lypinator 0:bb348c97df44 412 data_byte = reflect_bytes(data[byte]) ^ p_crc;
lypinator 0:bb348c97df44 413 p_crc = crc_table[data_byte];
lypinator 0:bb348c97df44 414 }
lypinator 0:bb348c97df44 415 } else if (width <= 16) {
lypinator 0:bb348c97df44 416 uint16_t *crc_table = (uint16_t *)_crc_table;
lypinator 0:bb348c97df44 417 for (crc_data_size_t byte = 0; byte < size; byte++) {
lypinator 0:bb348c97df44 418 data_byte = reflect_bytes(data[byte]) ^ (p_crc >> (width - 8));
lypinator 0:bb348c97df44 419 p_crc = crc_table[data_byte] ^ (p_crc << 8);
lypinator 0:bb348c97df44 420 }
lypinator 0:bb348c97df44 421 } else {
lypinator 0:bb348c97df44 422 uint32_t *crc_table = (uint32_t *)_crc_table;
lypinator 0:bb348c97df44 423 for (crc_data_size_t byte = 0; byte < size; byte++) {
lypinator 0:bb348c97df44 424 data_byte = reflect_bytes(data[byte]) ^ (p_crc >> (width - 8));
lypinator 0:bb348c97df44 425 p_crc = crc_table[data_byte] ^ (p_crc << 8);
lypinator 0:bb348c97df44 426 }
lypinator 0:bb348c97df44 427 }
lypinator 0:bb348c97df44 428 *crc = p_crc & get_crc_mask();
lypinator 0:bb348c97df44 429 return 0;
lypinator 0:bb348c97df44 430 }
lypinator 0:bb348c97df44 431
lypinator 0:bb348c97df44 432 /** Constructor init called from all specialized cases of constructor
lypinator 0:bb348c97df44 433 * Note: All construtor common code should be in this function.
lypinator 0:bb348c97df44 434 */
lypinator 0:bb348c97df44 435 void mbed_crc_ctor(void)
lypinator 0:bb348c97df44 436 {
lypinator 0:bb348c97df44 437 MBED_STATIC_ASSERT(width <= 32, "Max 32-bit CRC supported");
lypinator 0:bb348c97df44 438
lypinator 0:bb348c97df44 439 _mode = (_crc_table != NULL) ? TABLE : BITWISE;
lypinator 0:bb348c97df44 440
lypinator 0:bb348c97df44 441 #ifdef DEVICE_CRC
lypinator 0:bb348c97df44 442 crc_mbed_config_t config;
lypinator 0:bb348c97df44 443 config.polynomial = polynomial;
lypinator 0:bb348c97df44 444 config.width = width;
lypinator 0:bb348c97df44 445 config.initial_xor = _initial_value;
lypinator 0:bb348c97df44 446 config.final_xor = _final_xor;
lypinator 0:bb348c97df44 447 config.reflect_in = _reflect_data;
lypinator 0:bb348c97df44 448 config.reflect_out = _reflect_remainder;
lypinator 0:bb348c97df44 449
lypinator 0:bb348c97df44 450 if (hal_crc_is_supported(&config)) {
lypinator 0:bb348c97df44 451 _mode = HARDWARE;
lypinator 0:bb348c97df44 452 }
lypinator 0:bb348c97df44 453 #endif
lypinator 0:bb348c97df44 454 }
lypinator 0:bb348c97df44 455 };
lypinator 0:bb348c97df44 456
lypinator 0:bb348c97df44 457 #if defined ( __CC_ARM )
lypinator 0:bb348c97df44 458 #elif defined ( __GNUC__ )
lypinator 0:bb348c97df44 459 #pragma GCC diagnostic pop
lypinator 0:bb348c97df44 460 #elif defined (__ICCARM__)
lypinator 0:bb348c97df44 461 #endif
lypinator 0:bb348c97df44 462
lypinator 0:bb348c97df44 463 /** @}*/
lypinator 0:bb348c97df44 464 } // namespace mbed
lypinator 0:bb348c97df44 465
lypinator 0:bb348c97df44 466 #endif