i.MX RT 1176 FlexCAN FiFo EDMA transfer

[Flo1989]

Hi,

i have a project in which i have to extend the count of CAN IDs to be greater then the 64 Messageboxes the device is able to handle. So i decided to use for some IDs the FiFo with EDMA. I configured it like the evkmimxrt1170_flexcan_loopback_edma_transfer_cm7 example.

We are only using standard CAN IDs, no CAN-FD.

I can receive all IDs via this example, but i want to use it in another way and do not find any reference for that. Because in the provided example the dma Buffer always has to be filled completely bevore the Interrupt calls "flexcan_dma_callback" and i can read the messages.

I would like to poll the dma buffer asynchronously from the main loop. So I think, i first have to stop or something like that the edma, read how many meassages would be recieved, read these messages and start the next edma transfer.

Is there any example or reference how to do this?

Thank you very much!

Florian

[Hui_Ma]

Hi,

First of all, sorry for the later reply.

Unfortunately, we do not have dedicted eDMA demo for FlexCAN module, while customer could refer RT1170 SDK eDMA [channel_link] or [scatter_gather] demos to config eDMA before start to copy FlexCAN Message Buffer data. With eDMA channel link or scatter gather feature, customer can adjust how many message buffer be copied dynamically.

Wish it helps.

Mike