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questions about TPS65381 used for TMS570LS3137

Jiaming Sun
Expert 1300 points
Other Parts Discussed in Thread: TMS570LS3137

hi,all

     I want to use TPS65381 as powersupply and watchdog for TMS570LS3137,but the question is when I download program to TMS570LS3137 with JTAG, on this occasion，TMS570 can't feed the watchdog inside TPS65381,then  TPS65381 is going to reset TMS570.If it is so ,how can I solve this problem ?

   Hope to reply soon.Thanks a lot.

  • 0
    TI__Guru 59540 points

    Hello Jiaming,

    Can you provide more details about your problem? When you state that the TMS570 cannot feed the watchdog, what is the mechanism you are attempting to use to feed the watchdog. Note that this is not an automatic function. In other words, this has to be setup and maintained by your application software. The Watchdog on the TPS65381 also has to be setup/configured for use. The TPS65381 device is setup/configured through it's SPI interface. More information on the TPS65381 setup and use can be found here http://www.ti.com/product/tps65381-q1.

  • 0 in reply to Chuck Davenport
    Expert 1300 points

    hello

        The situation is that when I have to upgrade the program to TMS570 ,I connect the JTAG to  TMS570,download the program through the JTAG  ,during this process ,I think the TMS570 can't feed the watchdog in the TPS65381, then the TPS65381 reset the TMS570,so I have to isolate the reset signal from TPS65381,using a gate component in the reset signal connection between the TMS570 and TPS65381.Is there any other good method?

  • 0 in reply to Jiaming Sun
    TI__Genius 13810 points

    workaround:

    1. Hold on the MCU reset (nRST or PORRST)
    2. Power cycle the board
    3. Wait for 5 seconds, release the MCU reset

    By doing this the TPS will be held in safe mode, which provides the power but don’t reset the MCU.

    After the flash is reprogramed, please power cycle the board again. Bacause the TPS can only go from safe mode to active mode by a new ignition pulse, power cycling and CANWU signal.

    Regards,

    Haixiao

  • 0 in reply to Haixiao Weng
    Expert 1300 points

    Thank you for your answers.

    My understanding is that If the TMS570 dosn't feed the TPS65381 more than 5s,then TPS65381 goes into SAFE state ,and dosn't give reset signal ,does this affect the safe function of TPS65381?

    How  can TPS65381 guarantee its safety function?It depends on ENDRV pin?

    Hope to get your answers soon ,thanks a lot.

      

  • 0 in reply to Jiaming Sun
    TI__Genius 13810 points

    Jiaming Sun said:

    Thank you for your answers.

    My understanding is that If the TMS570 dosn't feed the TPS65381 more than 5s,then TPS65381 goes into SAFE state ,and dosn't give reset signal ,does this affect the safe function of TPS65381?

    HW: After power on, if TPS65381 does not receive the command in about 720ms, it will go to the safe state and does not give the reset signal. Safety: The Endrv is tied low. (If there are under voltage, over voltage, over temprature fault, TPS65381 will go to the reset mode).

    If TPS65381 does communicate the TMS570 device and go to active mode, after that, if the MCU does not serve the TPS65381 watchdog correctly (watchdog counter goes to 7), depending on the TPS65381 settings, it could go to safe state or reset state. Either way, the ENDRV will be tied low after the watchdog counter increase to 5.

    How  can TPS65381 guarantee its safety function?It depends on ENDRV pin?

    Hope to get your answers soon ,thanks a lot.