Resetting MDot.

[Ajay K]

I was reading thru’ MDOt Developer Guide related to resetting the MDot on page 32 as called out below. My question is do you have to execute steps 1 and 2 or is it execute steps 1 or 2? The reason I ask this is because on our custom board we have a separate module on the board which has a GPU pin connected to the mDot modules reset pin, since in the code we have configured the GPU Pin as a Digital Output pin, I was wondering based on the directions to reset the mdot, do we need to keep the digital o/p pin low to drive the mdot reset pin to low for little over 1ms and then drive the digital o/p pin to high for a few seconds and bring the digital o/p back to low?

Resetting the mDot
To reset the mDot
1. Drive the RESET signal low for at least TNRESET.
2. Select either:
Allow RESET to float. The internal pull-up resistor pulls it up.
Drive the RESET line high.
The processor starts executing code after the RESET line is high.

Thanks,
Ajay

[Ajay K]

Any thoughts multitech team?

[Leon Lindenfelser]

You need to perform 1 and 2. After driving NRESET low for 1ms, the GPU pin can be left floating so that the internal pullup pulls it high or the GPU can drive it high.

[Ajay K]

Thanks Leon for taking the time to respond and for the clarification. I have one other question, should the GPU continue to drive it high or should it be driven low once the reset is complete? I am wondering what state the GPU needs to be so it doesn’t keep resetting the mDot module.

Thanks,
Ajay

[Leon Lindenfelser]

It needs to be high. NRESET is connected to the NRST pin of the STM32F411 processor. If it is held low, the processor will remain in the reset state.

[Ajay K]

Awesome, Thanks a lot for the clarification!

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