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Forum: µC & Digital Electronics STM32F03x - SPI via DMA -missing CLK on MISO


von Jens (Guest)


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Hello,

I have got a Problem with an STM32F030 Device, using SPI via DMA.

I try to set and load Data from HC595 and HC165 chips via SPI.

SPI is configure in Full duplex mode and prescaled down to a frequency 
of 8Khz. MOSI and SLK are configured as AF - MISO as Input.

For SPI DMA Channel 2 (RX) and 3 (TX) in Interrupt Modus. Both are 
configured in same way. Only the Adress / Location for received and 
sending data is different. (two differed variables)

Sending Data to the HC595 chips works good. The clock is running for 
writing, but it turns of when writing is finished. But when I m trying 
to read Data tot the HC165 the DMA will be started but nothing happened. 
No clock are generated. The interrupt occurs - but no data arrived 
(because there wasn't any clock for shifting the data).

This there something known about an issue like that? Where can I search 
for finding the bug? I have no idea left at the moment.

Unfortunately I can not the post the code here right yet - because it is 
in company and I am at home right now.

Kind regards

Jens

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