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STM32F373CCT6 SPI issues

Question asked by prinster.jim on May 16, 2014
Latest reply on May 16, 2014 by Brutte

I am having issues with SPI1 and SPI2 on the STM32F373CCT6 chip.

 

1) I have both busses configured the same as full duplex, 16 bit data, master mode, baud rate scaler of 8.  However, when I look at the SPI clocks on a scope or logic analyzer they are different.  Is there some other setting that is causing this?

 

2) SPI2 seems to work just fine.  When I send data to the slave the clock shows 16 pulses.  However, when I do the same thing with SPI1 I get 17 pulses.  What could cause this?

 

3) I am using SPI1 to retrieve data from a TI ADS8866 ADC.  That device is trigger by an IO pin and then it transmits data on the master's clock.  With the SPI1 set up as full duplex, since this is a read-only device if I use the library function to read a 16 bit data, the SPI1 CLK does not produce any clock signals to retrieve the data.  I have had to resort to doing a write operation so the SPI1 generates the clock pulses (however it sends 17 pulses as I mentioned above).  Is there a command for reading that will cause the clock to be generated?  I don't want to configure it as RxOnly since that turns the clock on all the time and I have no way of turning it off after 16 pulses.

 

Thanks,

Jim

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