ARMmbed
/
mbed-os
mirror of https://github.com/ARMmbed/mbed-os.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

stm32: Improve the CRC function to support fully accumulate 

Tested on DISCO_L476VG and NUCLEO_L476RG
pull/9347/head
kevin.ong 2019-01-11 11:52:49 +08:00 committed by Cruz Monrreal II
parent 1a8844e8ed
commit 1c2ffb8eb3
1 changed files with 84 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

94
targets/TARGET_STM/mbed_crc_api.c
View File

@ -7,28 +7,56 @@
static CRC_HandleTypeDef current_state;
static uint32_t final_xor;
static uint32_t crc_mask;
/* STM32 CRC preipheral features
+-------------------------+-----------------------+---------------+---------------+
| Feature | F1/L1/F2/F4 series | F0 series | L0/F3/L4/F7 |
+-========================+=======================+===============+===============+
| Reversibility option | NO | YES |
| on I/O data | | |
+-------------------------+-----------------------+---------------+---------------+
| CRC initial Value | Fixed to 0xFFFFFFFF | Programmable | Programmable |
| | | on 32 bits | on 8,16,32 |
+-------------------------+-----------------------+---------------+---------------+
| Handled data size in bit| 32 | 8,16,32 |
+-------------------------+---------------------------------------+---------------+
| Polynomial size in bit | 32 | 7,8,16,32 |
+-------------------------+---------------------------------------+---------------+
| Polynomial coefficients | Fixed to 0x4C11DB7 | Programmable |
+-------------------------+---------------------------------------+---------------+
*/
bool hal_crc_is_supported(const crc_mbed_config_t *config)
{
if (config == NULL) {
return false;
}
if (config->polynomial != POLY_32BIT_ANSI) {
#if defined(TARGET_STM32F1) || defined(TARGET_STM32F2) || defined(TARGET_STM32F4) || defined(TARGET_STM32L1)
if (config->width != HAL_CRC_LENGTH_32B || config->polynomial != POLY_32BIT_ANSI ||
config->initial_xor != 0xFFFFFFFF || config->reflect_in || config->reflect_out) {
return false;
}
if (config->width != 32) {
#elif defined(TARGET_STM32F0)
if (config->width != HAL_CRC_LENGTH_32B || config->polynomial != POLY_32BIT_ANSI) {
return false;
}
if ((config->final_xor != 0xFFFFFFFFU) && (config->final_xor != 0)) {
#else
/* TARGET_STM32L0, TARGET_STM32F3, TARGET_STM32L4, TARGET_STM32F7 */
if (config->width != HAL_CRC_LENGTH_32B && config->width != HAL_CRC_LENGTH_16B &&
config->width != HAL_CRC_LENGTH_8B && config->width != HAL_CRC_LENGTH_7B) {
return false;
}
#endif
return true;
}
static uint32_t get_crc_mask(int width)
{
return (width < 8 ? ((1u << 8) - 1) : (uint32_t)((uint64_t)(1ull << width) - 1));
}
void hal_crc_compute_partial_start(const crc_mbed_config_t *config)
{
MBED_ASSERT(hal_crc_is_supported(config));
@ -36,21 +64,47 @@ void hal_crc_compute_partial_start(const crc_mbed_config_t *config)
__HAL_RCC_CRC_CLK_ENABLE();
final_xor = config->final_xor;
crc_mask = get_crc_mask(config->width);
current_state.Instance = CRC;
#if !defined(TARGET_STM32F1) && !defined(TARGET_STM32F2) && !defined(TARGET_STM32F4) && !defined(TARGET_STM32L1)
current_state.InputDataFormat = CRC_INPUTDATA_FORMAT_BYTES;
current_state.Init.DefaultPolynomialUse = DEFAULT_POLYNOMIAL_ENABLE;
current_state.Init.DefaultPolynomialUse = DEFAULT_POLYNOMIAL_DISABLE;
current_state.Init.DefaultInitValueUse = DEFAULT_INIT_VALUE_DISABLE;
current_state.Init.InitValue = config->initial_xor;
current_state.Init.CRCLength = CRC_POLYLENGTH_32B;
current_state.Init.GeneratingPolynomial = config->polynomial;
switch (config->width)
{
case HAL_CRC_LENGTH_32B:
current_state.Init.CRCLength = CRC_POLYLENGTH_32B;
break;
case HAL_CRC_LENGTH_16B:
current_state.Init.CRCLength = CRC_POLYLENGTH_16B;
break;
case HAL_CRC_LENGTH_8B:
current_state.Init.CRCLength = CRC_POLYLENGTH_8B;
break;
case HAL_CRC_LENGTH_7B:
current_state.Init.CRCLength = CRC_POLYLENGTH_7B;
break;
default:
MBED_ASSERT(false);
break;
}
current_state.Init.InputDataInversionMode =
config->reflect_in ? CRC_INPUTDATA_INVERSION_BYTE
: CRC_INPUTDATA_INVERSION_NONE;
current_state.Init.OutputDataInversionMode =
config->reflect_out ? CRC_OUTPUTDATA_INVERSION_ENABLE
: CRC_OUTPUTDATA_INVERSION_DISABLE;
#endif
HAL_CRC_Init(&current_state);
if (HAL_CRC_Init(&current_state) != HAL_OK) {
MBED_ASSERT(false);
}
}
void hal_crc_compute_partial(const uint8_t *data, const size_t size)
@ -62,9 +116,29 @@ void hal_crc_compute_partial(const uint8_t *data, const size_t size)
uint32_t hal_crc_get_result(void)
{
const uint32_t result = current_state.Instance->DR;
uint32_t result = current_state.Instance->DR;
return (final_xor == 0xFFFFFFFFU) ? ~result : result;
#if !defined(TARGET_STM32F1) && !defined(TARGET_STM32F2) && !defined(TARGET_STM32F4) && !defined(TARGET_STM32L1)
/* The CRC-7 SD needs to shift left by 1 bit after obtaining the result, but the output
* inversion of CRC peripheral will convert the result before shift left by 1 bit, so
* the result seems to have shifted after the conversion.
*
* Example:
* [Gerenal setps]
* 1. Before output inversion: 0x75 (0111 0101)
* 2. Left shift by 1 bit: 0xEA (1110 1010)
* 3. After output inversion: 0x57 (0101 0111)
*
* [STM32 CRC peripheral steps]
* 1. Before output inversion: 0x75 (0111 0101)
* 2. After output inversion: 0x57 (0101 0111) <= no needs shift again
*/
if (current_state.Init.CRCLength == CRC_POLYLENGTH_7B &&
current_state.Init.GeneratingPolynomial == POLY_7BIT_SD &&
current_state.Init.OutputDataInversionMode == CRC_OUTPUTDATA_INVERSION_DISABLE)
result = result << 1;
#endif
return (result ^ final_xor) & crc_mask;
}
#endif // DEVICE_CRC