DRV8889-Q1: nSLEEP toggle for 1ms

Arshiya Tabassum

Intellectual 975 points

Part Number: DRV8889-Q1

Hi,

I have a question related to the register configuration of DRV8889-Q1.

I am following the steps to configure the registers on this device , I have a question about this sequence.

1. Driver on - DRVOFF - LOW

2. Sleep mode off- nSLEEP - HIGH

3. Configure micro-stepping mode - CTRL 3 register (using SPI write)

4. Configure open load detection enable - CTRL 4 register ( using SPI write)

5. Configure stall detection - CTRL 5 register (using SPI write)

What happens if I write the nSLEEP to low and in a delay of 1 ms write it to high?

Something like this:

GPIO_write(nSLEEP_INDEX, LOW);
Osal_delay(1); // 1 ms delay
GPIO_write(nSLEEP_INDEX, HIGH);

Will I lose my register configurations?

Thank you,

Arshiya Tabassum

What happens if I

over 3 years ago

0 Michael Erdahl over 3 years ago

TI__Genius 13455 points

Hi Arshiya,

Pulsing nSLEEP for 1ms will have the effect of putting the logic core into low-power mode and resetting the register configuration.

Figure 7-22 in the datasheet shows how you can use nSLEEP to reset faults and keep the register settings. Basically you would pulse for at least 18us, and less than 35us.

Regards,
Mike

0 Arshiya Tabassum over 3 years ago in reply to Michael Erdahl

Intellectual 975 points

Thank you for your response.

I am trying to avoid that actually, because my design is based on RTOS, is there a work around this idea?

Thank you,

Arshiya Tabassum

0 Michael Erdahl over 3 years ago in reply to Arshiya Tabassum

TI__Genius 13455 points

Arshiya,

What is your goal? If you are trying to save power, but maintain register settings, you can disable the driver outputs, and leave nSLEEP deasserted. Pulsing nSLEEP for 1ms will reset the registers.

Regards,
Mike

0 Arshiya Tabassum over 3 years ago in reply to Michael Erdahl

Intellectual 975 points

My goal is to clear the faults when there is no option of CLR_FLT bit writing

Thank you,

Arshiya Tabassum

0 Michael Erdahl over 3 years ago in reply to Arshiya Tabassum

TI__Genius 13455 points

Hi Arshiya,

OK, I understand now.

Can you use the automatic recovery option (OTSD_MODE=1)?

If not, you will need to reprogram the registers after pulsing nSLEEP to clear the fault.

Regards,
Mike

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DRV8889-Q1: nSLEEP toggle for 1ms