TCAN1145-Q1: Wake from Sleep not possible after non NM frames

Hi Iulian,

Would you try to clear the CANINT interrupt after first wakeup? It is recommended to clear this interrupt every time before go back to sleep mode.

Let me know if this works

Regards,

Sean

Hi Sean,

In the current software, yes we do clear the CANINT interrupt after first wakeup and every wakeup and we do clear this interrupt every time before go back to sleep mode.

The current issue only when the non Wake-up Frame (WUF) the cluster doesn't wake up and gets stuck in some state that even Wake-up Frame (WUF) is not able to wake up the cluster.

NT1_1 register(51h)should have value 0x40 when the Wake-up Frame (WUF) message is sent to ECU but the value remains at 0x00 and CAN transceiver stays in sleep mode ag point 5 above.

We would need to understand in details what is causing the Cantransciever chip not able to detect Wake-up Frame (WUF)when the non Wake-up Frame (WUF) is sent before Wake-up Frame (WUF]is sent on the bus.

Br,
Shrinidhi

Hi Shrinidhi,

Yes INT_1 remains 0x00 because it's not successfully waked up, thus the CANINT flag is not set.

May I know that for step 4 and 5, is the WUF sent followed non WUF immediately? Or there is a time period between the two frame sent?

Also, could you confirm the WUF in step 5 is sent at the configured data rate as SW_CONFIG_1?

Regards,

Sean

Hi Sean,

There is a delay in steps 4 and 5. The Wake-Up Frame (WUF) is sent out approximately 2 seconds after the non-Wake-Up Frame (non-WUF), rather than immediately.

The WUF in step 5 is sent out with the configured data rate of 500 kbps, which is the same as the data rate configured in the CAN transceiver (cantrcv) driver configuration.

As mentioned, the issue only occurs when the non-WUF is sent before the WUF. Otherwise, the CAN transceiver detects the WUF after sleep every time if we don’t send a non-WUF in between.

Br,

Shrinidhi

Hi Sean,

• Even if we send a WUP again, followed by a matched WUF, we don’t wake up. Cantrcv is stuck in some state after Step 4 to Step 5 from the above ticket description.
• Irrespective of timing, if we don’t send Non-WUF first followed by WUF, the issue is not observed, and every time we wake up.
• Why does the issue happen only when the Non-WUF is sent first followed by WUF? What causes Cantrcv to get stuck and not be able to wake up even with the valid WUP and WUF?
  You can find the trace screenshot 0x555h WUP and WUF (0x500h)
  
  

Br,

Shrinidhi

Hi Shrinidhi,

Did you sent the WUF “immediately" after Non-WUF? Or still having that 2 seconds delay?

A WUP (or any bus activity) is required to enable the selective receiver in sleep mode. This is because the selective wake receiver consumes more power than the low power receiver, so the selective wake receiver will remain off until bus activity is detected. 

Is it possible to capture waveforms of the CANH and CANL signals during this test? Let's consider two different cases:

step 2: Only one WUF is send and successfully wakeup.

Is there any bus activity before sending the WUF? My guess is the controller can actually sent not only one frame, it is possible that the controller send the WUF again if no ACK bit is received, thus can you please capture the CAN bus waveforms, along with the INH output?

step 4 and 5: WUF is send after a non-WUF, but no wakeup.

Again, please capture waveform I mentioned above, it is possible that the controller actually didn't send the WUF, it continuously to send non-WUF due to not receiving ACK bit, then the WUF is never detected.

Regards,

Sean