TCAN1145-Q1: Selective wake up support

Hi Kuramochi-san,

Regarding your first question, it's described in section 10.4:

"The TCAN114x-Q1 automatically goes from sleep to standby mode when receiving a WUP or LWU event. When selective wake is enabled, TCAN1145-Q1 and TCAN1146-Q1, the device looks for a wake-up frame (WUF) after receiving a WUP. If a WUF is not received the device transitions back to sleep mode."

The answer is YES, WUF is mandatory for entering standby mode when selective wake is enabled.

For your second question, INH will be ON in all modes except sleep mode. During selective wake enabled INH will still be Floating as in the sleep mode.

Regards,

Sean

Hello Sean,

I confused your explanation.

You said "The TCAN114x-Q1 automatically goes from sleep to standby mode when receiving a WUP or LWU event. " and "If a WUF is not received the device transitions back to sleep mode.".
It seems that TCAN114x-Q1 will enter standby mode when received WUP even if selective wake is enabled.

However, you also said "WUF is mandatory for entering standby mode when selective wake is enabled.".
It seem device won't enter standby mode as far as it won't receive WUF even if TCAN114x-Q1 received WUP.
This is because, WUF must happen after WUP so TCAN114x-Q1 shouldn't enter standby mode if WUF is mandatory requirement entering Standby mode.

Which is correct explanation when they enabled selective wake up?

Best regards,
Kazuki Kuramochi

Kuramochi-san,

Kazuki Kuramochi said:

The TCAN114x-Q1 automatically goes from sleep to standby mode when receiving a WUP or LWU event.

This is correct, under sleep mode (selective wake not enabled), the device will need a WUP or LWU event to enter standby mode. Please note that I didn't mention WUF here.

Kazuki Kuramochi said:

However, you also said "WUF is mandatory for entering standby mode when selective wake is enabled.".

When selective wake enabled, WUF is required after the device receiving WUP for entering standby mode. The device will transition back to sleep mode if not receiving WUF after the WUP.

I hope this clarify my explanation.

Regards,

Sean

Hello Seen,

Your Full first description is as follows(add sequence# for easier understanding).

"The TCAN114x-Q1(1) automatically goes from sleep to standby mode when receiving a WUP or LWU event(2). When selective wake is enabled, TCAN1145-Q1 and TCAN1146-Q1, the device looks for a wake-up frame (WUF) after receiving a WUP. If a WUF is not received the device transitions back to sleep mode."

Then, it seems TCAN1145-Q1 follow below process.

1. Sleep mode
2. Move to standby by WUP or LWU.
3. WUF is (not) received.
4. Move to sleep(if WUF isn't receive).

Based on your description as below
Move to standby should happen between 3 and 4.
But your explanations has diffference.

Would you tell ne your answer?

Best regards,
Kazuki KUramochi

Kuramochi-san,

Let's just ignore everything above.

We need to consider two different situations, selective wake not enabled/selective wake enabled.

When selective wake not enabled:

1. Sleep mode 

2. WUP or WUF or LWU received

3. Standby mode

When selective wake enabled:

1. Sleep mode

2. WUP received

3. WUF received? 

4. If yes, enter standby mode

    If not, transition back to sleep mode

Back to your original question:

Kazuki Kuramochi said:

Then, Is WUF mandatory moving to standby mode or will TCAN1145-Q1 move to standby when it receive WUP and Selective wake is enabled?

When selective wake is enabled, both WUF and WUP are mandatory for TCAN1145-Q1 to transition from sleep mode into standby mode 

Regards,

Sean

Hi Eric, Sean,

Thank you for your explanation.
I understand that TCAN1145-Q1 has additional sleep mode to wait WUF.

Best regards,
Kazuki Kuramochi