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TCAN4550: About PWRON

Part Number: TCAN4550

Hi,

We have received the following inquiry from a customer, so please let us know.

Please tell me about the PWRON flag in Section 9.6.3. When PWRON=1
① Set this flag to 0 to enter normal mode.
or
② When the device enters normal mode, the flag becomes 0.
which one is correct?

I don't understand the CAN specifications correctly, so I didn't know if operation like ② was possible.

Thank you for your support.

Hiroshi

  • Hiroshi-san,

    Did you possibly mean Section 8.6.3?

    I am bringing in one of our experts on TCAN4550 to help with this question, but we might not be able to get back to you until next week. I appreciate your patience.

    Best,

    Danny

  • Hi Hiroshi-san,

    When the device powers on, the PWRON (Power On) flag in the Interrupt Register is set to generate an interrupt that will notify the MCU that the device has recently been powered on.  There is a failsafe safety feature that ensures the device does not wake up from Sleep Mode due to an error such as noise in the system and remains on drawing more current than expected.  After power on, a 4-minute timer is started and expects the MCU to respond by clearing the PWRON flag, or configuring the device and placing it into Normal Mode.  Placing the device into Normal mode doesn't clear the flag which is only done by writing a "1" to this bit.  However, placing the device into Normal Mode does stop the 4 minute Sleep Wake Enable (SWE) timer to prevent the device from switching back to Sleep mode.  If the PWRON flag has not been cleared and the device has not been placed into Sleep Mode, it will switch back to Sleep Mode.

    Regards,

    Jonathan

  • Sorry. As you pointed out, it was 8.6.3.
    Thank you for your answer.

  • Hi Hiroshi-san,

    You're welcome.  Let us know if you have any additional questions.

    Regards,

    Jonathan