2402412_en-US

[#1]

TJA1153 on S32K344EVB

The CAN transceiver on S32K344EVB is TJA1153, It need to do configuration for use as the datasheet said. But I find two phenomenon on my side.

1. I just pull high for both EN pin and STB pin of TJA1153, and it can communicate with partner normally, no need to do configuration.

2. I want to do configuration for it with EN pin high and STB pin low, use CAN ID such as 0x555U/0x18DA00F1 as datasheet said, after execute Can_43_FLEXCAN_Write, do while with Can_43_FLEXCAN_MainFunction_Write, but found CanIf_TxConfirmation never called. At next call for Can_43_FLEXCAN_Write, it returned CAN_BUSY.

So what's the reason for the two phenomenon?

Re: TJA1153 on S32K344EVB

Hi,

A few comments regarding the observed behavior:

1. Please first verify that the CAN transceiver on your board is really TJA1153. If a standard transceiver (e.g. TJA1043/TJA1042) is populated instead, no secure configuration sequence is required and normal CAN communication should work immediately. 

2. For a genuine TJA1153, the behavior depends on its current state:

• Vanilla state (factory default): configuration is required before normal operation, and entry to local configuration mode requires STB_N = Low. 
• Open-config/configured state: the transceiver may already allow normal communication. Reconfiguration can be performed without the initial bitrate detection frame (ID 0x555), by sending the prepared Classical CAN frame with the CONFIG_ID extended identifier at the configured baud rate. This configuration message must be ACKed by another node on the bus.

Regarding the second issue, if CanIf_TxConfirmation() is never called and the next Can_43_FLEXCAN_Write() returns CAN_BUSY, it indicates that the TX mailbox has not completed transmission. I would recommend checking the FlexCAN status registers (ESR1, ECR, MB CODE field) to determine whether the frame was actually transmitted and acknowledged.

BR, Petr