- HAL_CRC_Calculate(&hcrc, (uint32_t *)aDataBuffer, BUFFER_SIZE)
待计算的原始数据:
- static const uint32_t aDataBuffer[BUFFER_SIZE] =
- {
- 0x00001021, 0x20423063, 0x408450a5, 0x60c670e7, 0x9129a14a, 0xb16bc18c,
- 0xd1ade1ce, 0xf1ef1231, 0x32732252, 0x52b54294, 0x72f762d6, 0x93398318,
- 0xa35ad3bd, 0xc39cf3ff, 0xe3de2462, 0x34430420, 0x64e674c7, 0x44a45485,
- 0xa56ab54b, 0x85289509, 0xf5cfc5ac, 0xd58d3653, 0x26721611, 0x063076d7,
- 0x569546b4, 0xb75ba77a, 0x97198738, 0xf7dfe7fe, 0xc7bc48c4, 0x58e56886,
- 0x78a70840, 0x18612802, 0xc9ccd9ed, 0xe98ef9af, 0x89489969, 0xa90ab92b,
- 0x4ad47ab7, 0x6a961a71, 0x0a503a33, 0x2a12dbfd, 0xfbbfeb9e, 0x9b798b58,
- 0xbb3bab1a, 0x6ca67c87, 0x5cc52c22, 0x3c030c60, 0x1c41edae, 0xfd8fcdec,
- 0xad2abd0b, 0x8d689d49, 0x7e976eb6, 0x5ed54ef4, 0x2e321e51, 0x0e70ff9f,
- 0xefbedfdd, 0xcffcbf1b, 0x9f598f78, 0x918881a9, 0xb1caa1eb, 0xd10cc12d,
- 0xe16f1080, 0x00a130c2, 0x20e35004, 0x40257046, 0x83b99398, 0xa3fbb3da,
- 0xc33dd31c, 0xe37ff35e, 0x129022f3, 0x32d24235, 0x52146277, 0x7256b5ea,
- 0x95a88589, 0xf56ee54f, 0xd52cc50d, 0x34e224c3, 0x04817466, 0x64475424,
- 0x4405a7db, 0xb7fa8799, 0xe75ff77e, 0xc71dd73c, 0x26d336f2, 0x069116b0,
- 0x76764615, 0x5634d94c, 0xc96df90e, 0xe92f99c8, 0xb98aa9ab, 0x58444865,
- 0x78066827, 0x18c008e1, 0x28a3cb7d, 0xdb5ceb3f, 0xfb1e8bf9, 0x9bd8abbb,
- 0x4a755a54, 0x6a377a16, 0x0af11ad0, 0x2ab33a92, 0xed0fdd6c, 0xcd4dbdaa,
- 0xad8b9de8, 0x8dc97c26, 0x5c644c45, 0x3ca22c83, 0x1ce00cc1, 0xef1fff3e,
- 0xdf7caf9b, 0xbfba8fd9, 0x9ff86e17, 0x7e364e55, 0x2e933eb2, 0x0ed11ef0
- };
对于上面的hex数据,进行CRC-32计算,预期的结果是多少?可以使用下面这个在线的CRC计算工具
https://www.crccalc.com/?crc=123456789&method=CRC-32&datatype=hex&outtype=hex
在代码中,指定了CRC运算的时候,输入,输出都不翻转:
下图中的RefIn和RefOut都是false,表示输入数据和输出数据都不翻转,与代码设置保持一致。
除了用网页CRC计算器,也可以自己写一段python程序来计算CRC-32:
- data_buffer = [
- 0x00001021, 0x20423063, 0x408450a5, 0x60c670e7, 0x9129a14a, 0xb16bc18c,
- 0xd1ade1ce, 0xf1ef1231, 0x32732252, 0x52b54294, 0x72f762d6, 0x93398318,
- 0xa35ad3bd, 0xc39cf3ff, 0xe3de2462, 0x34430420, 0x64e674c7, 0x44a45485,
- 0xa56ab54b, 0x85289509, 0xf5cfc5ac, 0xd58d3653, 0x26721611, 0x063076d7,
- 0x569546b4, 0xb75ba77a, 0x97198738, 0xf7dfe7fe, 0xc7bc48c4, 0x58e56886,
- 0x78a70840, 0x18612802, 0xc9ccd9ed, 0xe98ef9af, 0x89489969, 0xa90ab92b,
- 0x4ad47ab7, 0x6a961a71, 0x0a503a33, 0x2a12dbfd, 0xfbbfeb9e, 0x9b798b58,
- 0xbb3bab1a, 0x6ca67c87, 0x5cc52c22, 0x3c030c60, 0x1c41edae, 0xfd8fcdec,
- 0xad2abd0b, 0x8d689d49, 0x7e976eb6, 0x5ed54ef4, 0x2e321e51, 0x0e70ff9f,
- 0xefbedfdd, 0xcffcbf1b, 0x9f598f78, 0x918881a9, 0xb1caa1eb, 0xd10cc12d,
- 0xe16f1080, 0x00a130c2, 0x20e35004, 0x40257046, 0x83b99398, 0xa3fbb3da,
- 0xc33dd31c, 0xe37ff35e, 0x129022f3, 0x32d24235, 0x52146277, 0x7256b5ea,
- 0x95a88589, 0xf56ee54f, 0xd52cc50d, 0x34e224c3, 0x04817466, 0x64475424,
- 0x4405a7db, 0xb7fa8799, 0xe75ff77e, 0xc71dd73c, 0x26d336f2, 0x069116b0,
- 0x76764615, 0x5634d94c, 0xc96df90e, 0xe92f99c8, 0xb98aa9ab, 0x58444865,
- 0x78066827, 0x18c008e1, 0x28a3cb7d, 0xdb5ceb3f, 0xfb1e8bf9, 0x9bd8abbb,
- 0x4a755a54, 0x6a377a16, 0x0af11ad0, 0x2ab33a92, 0xed0fdd6c, 0xcd4dbdaa,
- 0xad8b9de8, 0x8dc97c26, 0x5c644c45, 0x3ca22c83, 0x1ce00cc1, 0xef1fff3e,
- 0xdf7caf9b, 0xbfba8fd9, 0x9ff86e17, 0x7e364e55, 0x2e933eb2, 0x0ed11ef0
- ]
- def compute_crc32(data_list):
- poly = 0x04C11DB7
- crc = 0xFFFFFFFF
- for data in data_list:
- # 大端模式分解为4个字节
- for byte in [(data >> 24) & 0xFF, (data >> 16) & 0xFF,
- (data >> 8) & 0xFF, data & 0xFF]:
- for i in range(7, -1, -1): # 处理每个bit(从高位到低位)
- bit = (byte >> i) & 0x01
- feedback = ((crc >> 31) & 0x01) ^ bit
- crc = (crc << 1) & 0xFFFFFFFF
- if feedback:
- crc ^= poly
- return crc
- result = compute_crc32(data_buffer)
- print(f"CRC-32结果: 0x{result:08X}")
运行结果是:
这个预期结果也就是出现在demo里面的变量uwExpectedCRCValue的出处。
下一步就是验证STM32L5的硬件计算的CRC,如果计算结果与预期一致,点亮LED10.
编译,烧录:
- Erasing memory corresponding to segment 0:
- Erasing internal memory sectors [0 4]
- Download in Progress:
- File download complete
- Time elapsed during download operation: 00:00:00.295
- Verifying ...
- Download verified successfully
- Shutting down...
- Exit.
复位后,计算正确,LED10点亮。
参考:
粉丝分享 | 图说CRC原理应用及STM32硬件CRC外设 https://zhuanlan.zhihu.com/p/285124407