what is the output voltage of swo_d ?

[ps_anu]

Hi,

We are working on the customized board we used your reference design of nRF52832 . My question is what is the output voltage of swo_d pin in the fresh pcb without loading the program ?

Kind Regards 

bavithra k

[Einar Thorsrud]

Hi,

The pin will be high impedance (disconnected input). This is because the SWO is disabled by default (reset value of TRACECONFIG is all 0's), and GPIO's are disconnected after reset.

[ps_anu]

Thanks ,

Einar 

If my customized board is powered on by the coin cell battery , when the voltage will occur across the SWO_D pin after the flashing the code or else without code itself 

[Einar Thorsrud]

There will not be an output signal on the SWO pin unless your firmware enables it either as SWO or as GPIO. It is shared, as you can see here:

So generally, if you do not explicitly use those pins in your firmware, they will be high impedance. And for a device with empty flash SWO will always be high impedance.

[ps_anu]

what is meant by high impedance ? 3.3V right 

[Einar Thorsrud]

It does not really make sense to talk about voltage for a pin that is in high impedance (tri-state). You can think of it as if the pin is floating in the air, and not connected to the nRF at all. This article explains the concept.