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DRV 8350 MSP430F5529, Online debugging is normal ,but after disconnect EZ fet emulator, and repower the board, it needs to RESET to run.

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

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?

  • The usual suspect for such a symptom is power, particularly ramp-up. The debugger supplies constant power, and the supply is pretty steady after "human time" following a power-up. The F5 can deal with this but maybe you're trying to talk to your device(s) too soon.

    A quick experiment is to insert a delay, e.g. "__delay_cycles(1000000UL); // 1 second" at the beginning of main() (right after stopping the WDT). If that helps, that points you in some direction.

  • Hi, Thank you for your reply.

    Just followed your instructions, I have tried just now. but it still do not works.   The only difference is the LED on my board which indicated the CPU works lighted later than before. the LED  D2 and D7 lighted means there is fault just like below.

    the reference  code is DRV8350H_EVM   E:DRV8350x_EVM_BLDC_FW_1.0.0\DRV835X_MSP430F5529_Trapezoidal_Sensored_BLDC

    Also , I have tried another __delay_cycles(),It still do not works. and still need to  RESET to run.why?

    another, as you say, The F5 can deal with this but maybe you're trying to talk to your device(s) too soonwhat is so called F5  in your answer.  I have the other development board, I can have a try.

    Waiting for your reply.

    Best regards,


  • Skimming the source code, it seems that having both LEDs on indicates a Gate Driver Fault (GDF in the FAULT1 register). I expect you know much more about BLDC drive than I do. Does this sound like something that could "normally" happen on power-up?

    By F5 I just meant the MSP430F5529 MCU on the board, which is part of the "F5 series". The F5 devices are somewhat less sensitive to slow power-ramp than, e.g. the F1 and F2 series devices.

  • Yes, the led indicated the how cpu works, as I have powered the board. the led2 is on ,the led7 is off. It means that the Fault is OVERTEMPERATURE.    but  I used the DRV8350H, From the code, it will not check the fault register.

  • I'm not quite clear on your (visible) symptom -- is it "LED  D2 and D7 lighted" or "the led2 is on ,the led7 is off"? Whichever the underlying fault, it seems that it's something that can appear as a transient during power-on, and it may be that the firmware isn't properly recovering when it happens at startup.

    In either case, this seems more a question about the DRV8350 (and/or the EVM) than the MSP430. I expect you'll get a quicker answer over in the Motor Control Forum over here:

  • Yes,  "the led2 is on ,the led7 is off".

    It really seems like something that can appear as a transient during power-on ,   The first time I Power on ,it can not run ,but as I power-off the board and quickly power on the board, It can run   normally. It's so strange!

  • I encourage you to ask this question over in the Motor Drivers forum; I expect someone there will recognize your symptom.

    You might encounter a motor-control expert here, but that Forum has a bunch of them -- it's even possible the person who wrote the firmware is over there.