About USB function on nRF52840

RE: About USB function on nRF52840

Andreas — Mon, 29 Apr 2019 14:58:25 GMT

Hi,

- VBUS detected, meaning VBUS rising past the detect voltage, is the only USB-related wake up source. The USB peripheral is shut down in SystemOFF, meaning D+/D- activity will not have any effect inside the nRF52840.

- In the SystemON state (can be considered a shallow sleep state) the USB periperal can be used as normal. All interrupts and events/tasks works as normal.

Best regards,

Andreas

RE: About USB function on nRF52840

Beren.Lei — Wed, 24 Apr 2019 01:23:10 GMT

Hi Andreas,

OK, we got it. We will provide VBUS within 5V, so the voltage of VBUS has no doubt.

But when we keep VBUS alway on, do you mean that as below:

--When system enters off and USB(only D+ &D-) plug in/out, VBUS can't wakeup SOC?

--When system power on and USB(only D+ &D-) plug in/out, can USB port be enumerated normal?

--When system power on and USB(only D+ &D-) plug in/out, can system of SOC goes into sleep?

TKS.

RE: About USB function on nRF52840

Andreas — Tue, 23 Apr 2019 13:59:14 GMT

Hi,

As you say, VBUS must be within 4.35V and 5.5V. Voltage lower than this is outside the specified voltage range, and the module has not been verified outside that.

USB can be always on, but note that it will be disabled if the SoC enters system OFF. Wakeup from VBUS will require VBUS to be toggled on and off to wake up from that source.

Best regards,

Andreas