RE: SPIM DMA LIST MAXCNT change

June6 — Tue, 09 Feb 2021 13:32:15 GMT

Hi, squwal

At present, I also have a project that needs to use SPI DMA to ensure the continuity of SPI receiving data. Gpiote interrupt is also used to trigger SPI read / write. Can you briefly provide the partial code of PPI connecting SPI and gpiote, and the partial code of setting SPI DMA read-write cache.

Now I have finished the part of using PPI to connect SPI and gpiote. When gpiote is interrupted, an SPI callback can be generated.

But I don't know if my method is correct or not, and how to make MCU not participate in SPI reading and writing automatically by hardware DMA. I don't know how to set it.

I hope you can give me some advice to help me understand and solve this problem.

Best regards！

June6

RE: SPIM DMA LIST MAXCNT change

Håkon Alseth — Mon, 18 Jan 2021 13:18:46 GMT

Hi,

[quote user=""]I wonder how to change the maxcnt dynamicly without CPU intervention? [/quote]

You cannot adjust the size without CPU intervention. ArrayList is a linear feature:

https://infocenter.nordicsemi.com/topic/ps_nrf52840/easydma.html?cp=4_0_0_3_5_1#arraylist

Kind regards,

Håkon