AM623: Problem with MCAN+PDMA on A53

Ichikawa Tatsuya

Part Number: AM623

Hello.

I am working in the following environment:

Device: TQMa6234L (CPU: AM62x)
SDK: mcu_plus_sdk_am62x_11_01_00_16
IDE: CCS 20.2

According to the AM62x Processors Technical Reference Manual, it is stated that Peripheral DMA can be used with MCAN0.
However, when Sciclient_rmPsilPair() is executed for MCAN0 on the A53, an ACK for TISCI_MSG_RM_PSIL_PAIR is not returned.
Does this mean that, by specification, using MCAN0 with PDMA from the A53 is not supported?
If it is possible to use MCAN0 with PDMA from the A53, what is the correct way to do so?

It has been confirmed that both UART and SPI utilize DMA through the same mechanism.

20 days ago

0 Ritapravo Sarker 18 days ago

TI__Expert 8200 points

Hi,

The assigned expert is out of office today. Please expect a reply within the next 2/3 days.

Regards,
Ritapravo

0 Meet Thakar 10 days ago in reply to Ritapravo Sarker

TI__Genius 17330 points

Hi,

DMA mode of operation is not supported in the SDK: https://software-dl.ti.com/mcu-plus-sdk/esd/AM62X/11_02_00_23/exports/docs/api_guide_am62x/DRIVERS_MCAN_PAGE.html#autotoc_md636

Could you please elaborate your use case here and let me know why there is a requirement of using DMA with MCAN as this is not supported in MCU+SDK.

Best Regards,

Meet.

0 okawachi hiroshi 2 days ago in reply to Meet Thakar

Prodigy 10 points

Hi Meet,

Thank you for your response.
I am responding on behalf of Ichikawa.

I understand that the MCU+ SDK currently does not support DMA mode for MCAN, as stated in the SDK documentation.

However, the point I would like to clarify is regarding the hardware capability of AM62x MCAN0.
According to the AM62x TRM, MCAN is listed as a peripheral that supports PDMA, similar to UART or MCSPI.
Therefore, my main questions are:

Does the AM62x hardware (MCAN0) actually support Peripheral DMA?
In other words, is the lack of DMA support only a software/SDK limitation, or does MCAN0 have a hardware restriction that prevents PDMA use?

If MCAN0 hardware does support PDMA, is it possible to enable DMA from the A53 by implementing manually (similar to MCSPI)?

Regarding the use case:
Our goal is to minimize software intervention and handle CAN communication with as little CPU load as possible,

Best Regards,

0 Meet Thakar 1 day ago in reply to okawachi hiroshi

TI__Genius 17330 points

Hi,

PDMA is supported by hardware for MAIN domain MCAN with some limitations:

Please also refer to Tx channel allocated for Main Domain MCAN from table 11-77 in the TRM.

Best Regards,

Meet.

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AM623: Problem with MCAN+PDMA on A53