DETECT signal nrf52840

[Martijn]

Can someone tell me how the DETECT signal works in the nRF52840? This version of the nrf52 has 2 GPIO ports. Does that mean there are 2 DETECT signals? or is there still one and are all SENSE levels of both ports ORed into a combined DETECT? Does a clear of the LATCH register in P0 also reevealuate the DETECT signal of the P1 pins? The documentation is exactly the same as the nrf52832, which only has 1 GPIO port

[Hung Bui]

Hi Martijn,

It's true that we have 2 GPIO ports. But the DETECT signal are single. So DETECT from both ports are connected together.

SENSE level of a pin on any port will result in a DETECT signal.

A clear of the LATCH on one PORT won't cause DETECT signal in normal mode to change. I guess you are talking about the LDETECT mode ? I haven't tested my self but I believe it will cause the common DETECT signal a pulse as showed in Figure 23 in the spec. I think it worth to test.

The implementation in our SDK is not using LDETECT for now.

[Martijn]

Yes, you are correct, I meant LDETECT mode. I do not have nRF52840 here right now, but i was writing a common driver for both versions, but could not find any clear documentation about this. For now I implemented it exactly like you said and will test when we have a nRF52840 here. It works as expected on the nRF52832.

[Hung Bui]

I agree, the documentation could be clearer regarding the 2 ports and how DETECT is connected especially if one is in DETECT mode and one is in LDETECT mode.

[Martijn]

Good point! didn't even think about that. How does it work in that case?

[Hung Bui]

I would assume that the common DETECT should still have the pulse. But I haven't tried myself :)