• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 84 subscribers
  • Views 730 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMS320F28069: TMS320f28069

Chandrakant Pal
Intellectual 500 points
Part Number: TMS320F28069


Hi All,

Is it possible to wake the device from LPM mode using CAN i.e. when CAN module will be in low power mode , i will enter the microcontroller in LPM mode and whenever there is any CAN bus activity on bus, i should be able to wake the CAN module from LPM and then microcontroller from LPM.

And how to decide whether in which mode we should put the microcontroller i.e. in IDLE , Standby and Halt mode.

Regards,

Chandrakant Pal

  • 0
    Guru 30330 points
    Hello Chandrakant,

    The only LPM where it is possible to wake with CAN activity is in IDLE mode. In Idle Mode, all peripherals may remain operational, and any enabled interrupt will allow the CPU to resume operation.

    There are tradeoffs between each LPM. Are you looking for the lowest power? fastest wake-up time? specific wake-up source? Each of these things will need to be considered when deciding which LPM to use.

    See Section 6.7 Low-Power Modes Block www.ti.com/.../detailed_description
    and Section 5.7 Power Consumption Summary www.ti.com/.../specifications for more information on the LPMs on this device.

    Thanks,
    Mark
  • 0 in reply to Mark Labbato
    Intellectual 500 points
    Hi Mark,

    Thank you for your reply. I have gone through the link and it was useful to understand the LPM.

    1.But i have a doubt suppose if CAN module is also in low power mode using PDR bit and I have set WUVA to wake up CAN module when any activity takes place on CAN bus and at the same time i have entered the Microcontroller in IDLE mode(LPM) will the activity on bus be able to awake the CAN module and based on PDR bit i can write a routine to awake the microcontroller, If CAN is polling based and if the CAN is interrupt based will the interrupt automatically awake the microcontroller and so i will have to enable the clocks.

    2,How will i come to know that microcontroller has to be awake or an interrupt has arrived and we have to enable all the pheripherals.

    Regards,
    Chandrakant Pal
  • 0 in reply to Chandrakant Pal
    TI__Guru* 95315 points

    Chandrakant,

                You need to clarify your objective for low-power mode.

     

    HALT gives you the lowest power, but slowest wakeup time.

    IDLE gives you the fastest wakeup time, but lowest power saving.

    STANDBY is midway in both.

     

    Unless you clarify your objectives, it is hard to give guidance. From a power saving point-of-view, the system level powerdown-modes (IDLE, STBY & HALT) offer more power savings than the powerdown-mode internal to the CAN module.

     

    Peripheral interrupt can wake up the device only from IDLE mode.

     

  • 0 in reply to Hareesh Janakiraman
    TI__Guru* 95315 points
    Chandrakant,
    Were you able to resolve the issue? If so, let us know how and close the post.
  • 0 in reply to Hareesh Janakiraman
    Intellectual 500 points
    Hi Hareesh, Mark

    Thank you for your reply. I am able to resolve my issue and I am able to enter microcontroller in idle mode and make the CAN module also in LPM mode. I am also able to wake up when CAN interrupt occurs i.e. CAN msg is received on CAN bus.

    Regards,
    Chandrakant Pal