S32K344 MCAL: CAN FD TX works (64 bytes) but RX indication not triggered for CAN FD frames

[potato]

Hi, all

I'm working with S32K344 using NXP AUTOSAR MCAL CANIF (FlexCAN).
I'm facing an issue with CAN FD reception.

Environment:
- MCU: S32K344 (WB ev board)
- RTD: 5_0_0_D2408_ASR_REL_4_7_REV_0000_20241002
- ASR: ASR_REL_4_7_REV_0000

Current behavior:
- CAN FD transmission works correctly.
→ 64-byte CAN FD frames are transmitted successfully.
- Classic CAN reception (8 bytes) works correctly.
→ CanIf_RxIndication() is called as expected.
- CAN FD reception does NOT work.
→ When a CAN FD frame is sent to this node, RxIndication is not called.

- As an additional check, I manually modified the generated code to set:

DataInfo.fd_enable = FALSE -> TRUE;
DataInfo.data_length = 0U -> 64U;

- However, CAN FD reception still does not work.

uestions:
- Is there any additional configuration required for CAN FD reception in FlexCAN MCAL?
- Is CAN FD reception supported on normal Rx Message Buffers, or is Enhanced FIFO required?
- Are there any known limitations or restrictions for CAN FD Rx on S32K344 MCAL?

Any guidance or reference would be appreciated.

[Julián_AragónM · Accepted solution]

Hi @potato,

Thank you for sharing your configuration. 

Q1. No, as long as both nodes are configured as CANFD.

Q2. & Q3. No.

Since you are using CAN instance in interrupt mode, please confirm if the interrupt controller (Platform) is correctly configured (CAN0 IRQ), and initialized before calling CAN reception.

You can use the community examples as reference:

• [RTD600 MCAL & IP] S32K3X4EVB-T172 FlexCAN Example Interrupt/Polling
• Example S32K344 FlexCAN_Ip TX/RX/EnhanceRXFIFO DMA test S32DS3.5 RTD400

Best regards,
Julián

[potato]

Thanks for the support.

This issue was not a problem in MCAL or RX configuration.
Everything was working as expected.

The root cause was that the transmitter was sending Classical CAN frames,
not CAN FD frames.
Because of that, the received data length was always 8 bytes.
After changing the transmitter to send CAN FD frames, RX indication worked
correctly with 64 bytes.

Thanks again.