1) Functions reading bit from PAL now return ioline_t type.
2) Functions that handle acquired buffer with acquired bits
now use uint8_t type because it corresponds to buffer type.
3) Cryptic bit shifting in bit storage functions replaced by
dividion operations because all modern compilers perfectly
optimise such operations.
This patch includes a high level and two low level drivers.
The high level driver is enabled with flag HAL_USE_CRC
The low level drivers include:
* Hardware CRC for the STM32 cortex processor lines.(when supported)
* Enabled with flag STM32_CRC_USE_CRC1
* DMA is enabled with CRC_USE_DMA
* SYNC api will use DMA, but put calling thread to sleep
* ASYNC api enabled.
* DMA Disabled
* SYNC api spin while calculating CRC
* ASYNC api disabled
* Software CRC (3 modes)
* CRCSW_CRC32_TABLE - Enables crc32 with lookup table.
* CRCSW_CRC16_TABLE - Enables crc16 with lookup tables.
* CRCSW_PROGRAMMBLE - Enables any crc done with computation.
* Can calculate any crc configuration.
* CRC_USE_DMA obviously not support with software CRC