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Wrong RXCRC for SPI3 with 18Mhz

Question asked by joee on Apr 3, 2012
Latest reply on Apr 5, 2012 by Clive One
I've interesting behavior on STM32F105VC. I have SPI3(remmaped) master with SPI auto CRC calculation (RXCRC,TXCRC). For 9Mhz it is fine, for 18Mhz I receive all words correct, including
CRC, but RXCRC register is wrong and CRCERR is set. See below


                       18 MHz result
spi3_rxcrc_wrong.JPG

Tx frame :
spiFrameWithoutCRC (matlab endian) = '0400050000000000000000000000000000000000000000000000000000000000000000000000';
calculated crc : 990B
txcrc: 990B

Rx frame:
spiFrameWithoutCRC( matlab endian) = '0100020000000000000000000000000000000000000000000000000000000000000000000000';
calculated crc: 5A0 (binary 10110100000)
rxcrc:              2D0 (binary 1011010000)
data register: 5A0

Here is just to be sure a 9MHz result

spi3_rxcrc_ok.JPG

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