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STM32F0 SPI CRCERR bit problem (with DMA)

Question asked by helton.gregory.002 on Jan 30, 2015
Latest reply on Feb 8, 2015 by helton.gregory.002
I seem to have a problem with the CRCERR bit in the SPI SR for a STM32F031. The CRC generator is turned on, and the RXCRCR gives the correct CRC for the message received. A string of bytes is sent (hex 81 02 00 00 00 00 01) with the 01 being the CRC value for the previous six bytes. The CRCPOLY is 0x107.  When all of the bytes are sent, including the CRC, the RXCRCR is 0x0000 - which is correct since a CRC of the CRC value results in 0. In this case, the CRCERR flag is clear as expected. However, to test a bad case, the 01 was replaced with 0x45. This should have resulted in the CRCERR flag being set, but it was not.

A file is attached which has some screen snapshot data of the registers after the data packet was received.  Any help would be appreciated.

Thanks in advance.