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SPI DMA is not workng at higher SPI baud rates

WCarey
Associate III

Hi,

My NUCLEO-H563ZI application uses SPI with DMA. The SPI transactions are not working at clock/2 clock/4 and clock/8 rates, clock being 250 Mhz. Is there any clock frequency restriction when SPI is used with DMA?

WCarey_0-1713875592886.png

 

3 REPLIES 3
Uwe Bonnes
Principal II

Give context! Explain your setup! What means "not working?  What is your setup?

This is my SPI Configuration.

WCarey_0-1713877617979.png

Upto a clk freq of SPI_BAUDRATEPRESCALER_16 (250/16 = 15.625 Mhz), my SPI transactions work i.e the 10 bytes I send from Master are coming up on the MOSI line. And my slave also behaves correctly.

WCarey_1-1713877686187.png

However, for frequencies above that (say SPI_BAUDRATEPRESCALER_8), the clock pin does not show any pulses!!

WCarey_2-1713878704784.png

 

 

 

 

You do not show your GPIO Setup. Is GPIO set for appropriate speed? How is your wiring? On-Board, on Board with jumper wires or bord-tp board with some cable or jumper wires? Did you look at the signal with a fast scope? 30 Mhz signals need some thoughts and care!