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DRV8350H-EVM: DRV8350H MSP430F5529 development board need to reset or power-off but quickly repower can run normally.

Part Number: DRV8350H-EVM
Other Parts Discussed in Thread: MSP430F5529, LP-MSP430FR2476, DRV8350

I have developed a new board used to driver BLDC, It mainly used DRV 8350  and  MSP430F5529,  but I don't use the onboard emulator but use the EZ_FET emulator from LP-MSP430FR2476 DEVEOPMENT kit. when debugging ,I only use the SBWTDIO / SBWTCK  and  GND. During Online debugging it is normal ,the motor can run as I want ,everything is ok. but after disconnect  EZ fet emulator, and repower the board, The board needs to RESET to run. Why?

also,  when I power-off the board and quickly repower the board , It can run normally. It's likely that something is happening during the power-up and appear the fault , So The MCU does not work.

The reference  code is DRV8350H_EVM   E:DRV8350x_EVM_BLDC_FW_1.0.0\DRV835X_MSP430F5529_Trapezoidal_Sensored_BLDC,

with only a little code changed , the led2 is lighted and led7 is off. So  I have changed the code which indicated If the MCU WORKS like below. the led2 and led7.

I have found that during power-up, the code runs in the ISR.c  . since I have changed the sensoredTrapController.Drection == FALSE. and downloaded the code into f5529,the led 2 is off and LED7 IS on, but the board still do not works. why? 

I have also put a thread below. The expert recognized me to ask here.

(+) DRV 8350 MSP430F5529, Online debugging is normal ,but after disconnect EZ fet emulator, and repower the board, it needs to RESET to run. - MSP low-power microcontroller forum - MSP low-power microcontrollers - TI E2E support forums

  • Hi Scaler,

    Thanks for posting your question to e2e - I am looking into this and will follow up with any questions or clarifications needed 

    Thanks and Best Regards,

  • Hi Scaler,

    For some initial feedback, we think this same question may have already been posted in another thread. Is this correct?

    If so, some of the initial feedback we got from the MSP430 team was that having this reset signal would not be a major problem.

    • They also made the suggestion of connecting the emulator when the board is powered off, and then doing the emulator power-up after the board connection is complete.  

    As for some of the additional questions I am seeing throughout the ongoing threads, here's what I can say from the DRV8350 device's side: 

    1. Can you let me know if the method mentioned above by the MSP430 team resolves your issue on the RESET pulse being needed at startup?
    2. In the case of problems at start-up, are you saying that you are seeing a fault trigger from the DRV device?
      1. this can be confirmed by monitoring the nFAULT pin itself on the DRV device during power-up. (The pin will pull logic low during a fault) 
      2. since you have the hardware 'H' version of the DRV device, it won't tell you exactly what type of fault is occurring
      3. however, the table below is from the DRV8350 datasheet and will give some insight as to what possible fault conditions could be happening. 
      4. usually, if it's during initial motor start-up,
        1. you can run into undervoltage protections like VM_UV, VDR_UV, VCP_UV, VGLS_UV since the device is not done powering up its main supply yet.
        2. Additionally, if you are trying to do something like operate the motor very aggressively during start-up, you might trigger overcurrent faults
        3. also, gate drive faults may also be possible if you try to operate the DRV device with INx signals before it is done powering up.
        4. I saw a mention of overtemp fault activating in the other thread, but this is unlikely at motor startup since your system has not yet had a chance to operate at full load to heat up the system 

    Hope this helps resolve some of your questions, and let me know if there is any additional clarification needed. 

    Thanks and Best Regards,

  • Sorry. I have clicked the wrong place. this do not resolved my question. because I have also put the problem in the Chinese E2E forum for help  , So the link you put above is also my expert who answers my question in the Chinese E2E forum! That's the same question.

    1.everytime  I do like this. Connecting the emulator when the board is powered off, and then doing the emulator power-up after the board connection is complete.  

    2.when I reset de MSP430 during the power- up, it can run normally.

    3.likely there is no fault during power-up from DRV. Because every time   I power up the board the led2 lighted and led7 off which correspond to the LED1 lighted and LED2 off in the firmware like below.

    So I have changed the code circled in red to the P1OUT &= ~BIT0;  P4OUT |= BIT0 and reload the firmware to the board. The leds do not toggle. So that not the problem from the FAULT state.

    4.Likely, The board do  not run  during power-up. likely it went to sleep. So need to RESET? 

    Waiting for your answer.

     Thanks and Best Regards,


  • Hi Scaler,

    Let's continue this discussion in the other thread, just to make sure we keep all the information in one place for a more organized debug process. 

    • Will close this specific thread for now, and will post my answers in the other thread moving forward

    Best Regards,