I have set up a project with the STM32H7B3 where I want the LPTIM1 to generate a synchronization signal that triggers a DMA driven SPI trancieve of 6*11 bits. The SPI is set up with wordsize 11. The DMA for both rx and tx is set up in circular mode with half-word data alignment. DMA number of request is set to 6.
In the process of getting it to work I started with only one request and it works. Increasing to 6 leads the DMA or the SPI to go into overrun. When reducing number of request to 4 it is working.
Is there a limit to the number of request the DMA streams can handle?
The AHB1 is running at 200 MHz and the SPI clock frequncy is 20MHz. I have tried lowering the SPI clock with the same result.
