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TM4C1231E6PZ: Does the device offer a CAN wake-up funcationality / low power mode?

Isee
Expert 5950 points
Part Number: TM4C1231E6PZ

Hi Team,

my customer is wondering if it is possible offer a CAN wake-up/sleep functionality? Meaning TM4C should be in some sort of low power mode and start up on CAN signal. 

Thank you!

Regards

Andreas

  • 0
    TI__Guru**** 180446 points

    Hi Andreas,

      I have passed your question to our CAN expert. 

  • 0 in reply to Charles Tsai
    TI__Guru 72500 points

    There is no built-in support for wake from CAN. The two options are to run from PIOSC at 16MHz which roughly cuts the power in half (~20mA), or to attach the WAKE- signal to the CANRX signal. The latter solution gives low power, but the micro will wake on each CAN message, but will not be able to recognize what that message was.

  • 0 in reply to Bob Crosby
    Guru 117855 points

    Hello Bob,

    Yet you HAVE provided a 'unique method' of meeting the client's 'Wake upon CAN Signal' demand - at only the cost of, 'ONE Dummy Message (and perhaps - just 2 (free) GPIO!')   

    Now 'If 2 free pins (were) available - I'd 'route your suggested 'CANRX' to 'Free Pin #1' (triggering an interrupt) and have Pin 1's 'ISR' drive 'Free pin #2' - to 'Latch Wake On.'   After a suitable period of 'silence' upon CANRX - 'Free pin #2' - can 'return the MCU to "low power!"

    All from your idea - simply/slightly - extended/adapted) here...   Note that (only) the 'Initial - 'Awake from sleep' CAN Message is lost' - ALL others are 'Alive & Well' for as long as 'CANRX' remains (somewhat) active!    Should those '2 spare GPIOs NOT be available' - then the (always dreaded) 'Addition of external Hardware' - can (still) 'SAVE the DAY!'   How's that?    The arrival of a toggle upon 'CANRX' will 'Trigger a One-Shot  (Output - of course tied to 'Wake') - and hold it ON - long enough for all messages (post) the dummy (initial) message to be 'received & processed.'  

    Note too - Rising FAR beyond 'Vendor-Client Poster's Request' - this 'Awake Upon Request' - may be deployed upon OTHER Serial Bus Networks (UART, SPI, I2C) as well - although (it is possible) that another GPIO may be required - to 'Reset' the Awakened Peripheral ... along w/the equally Awakened MCU!   (It is expected that - similar to the CAN Bus - a 'Signal Buffering' device (may) be required - affront the MCU's Serial Peripheral which is 'Teased into such MCU Wake-Up Service!'    Yet with (little) kicking/screaming - as signal handling has (already) been generally described above!)    

    This proves a reasonable 'Vendor/Outsider collaboration' ...  (maybe)   ...  does it not?