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stm32f4 to stm32f7 port Spi wrong clk signal

Question asked by Fehrenbacher.Christi on Dec 12, 2016
Latest reply on Dec 13, 2016 by Fehrenbacher.Christi


until now I have a custom board with a stm32f4 and it works fine with the standard peripheral lib.

I tried the new stm32f767 and the board started working after a few changes.

Except the SPI, I can receive and transmit data, the CS works, but the clock signal is wrong.

I need a data length of 8 bit, but I get 16 Bit.

(I get 16 pulses at the clock pin instead of 8, the signal on MOSI, MISO and CS are correct)

I don't see my mistake in the register settings, what did I miss?


spi2->CR1     : 0x035D
spi2->CR2     : 0x1700
spi2->SR      : 0x0643
spi2->DR      : 0x040C
spi2->CRCPR    : 0x0007
spi2->RXCRCR  : 0x0000
spi2->TXCRCR  : 0x0000
spi2->I2SCFGR : 0x0000
spi2->I2SPR      : 0x0002


I don't use HAL because it would be a lot of work to port the whole project and the register differences are small.

Thanks for every suggestion.


Kind regards