pca10056 vddio and REGOUT0 setting

RE: pca10056 vddio and REGOUT0 setting

Julie H — Tue, 20 Jun 2017 16:41:35 GMT

Greetings -

The problem was caused by my using the wrong address to read the EXTSUPPLY (offset 0x300) and REGOUT0 (0x304) values. I was using a base address of 0x10000000 instead of the correct address of 0x10001000. When I used the correct value I found that both values in the UICR were uninitialized (0xFFFFFFFF). After programming the desired values (0x01 and 0x04) to those two locations using nrfjprog, respectively, all is well.

RE: pca10056 vddio and REGOUT0 setting

Julie H — Tue, 20 Jun 2017 14:04:54 GMT

Kristin -

As noted in the original question, EXTSUPPLY is 0x01 and the low order 3 bits of REGOUT0 are 0x4. There are some other set bits in REGOUT0, but the documentation for that register indicates that only the low order 3 bits are used.

We did measure pin 20 yesterday and it had 3.0 volts as well.

One observation - when NOT using the SoftDevice on an example, the GPIO voltage on an LED was measured at 3.0 volts. As regards which GPIO pins had 1.8 volts, it has been a sampling of pins on both GPIO ports.

RE: pca10056 vddio and REGOUT0 setting

FormerMember — Tue, 20 Jun 2017 10:58:48 GMT

The reason for the measured 1.8 V could be related to how the power supply is connected (VDD/VDDH), see the Objetive Product Specification, chapter "Power supply --> main supply" : "High voltage mode is entered when the supply voltage is only connected to the VDDH pin and the VDD pin is not connected to any voltage supply."

How is the power supply connected on your board?

On the PDK, high voltage mode is obtained by powering the chip from the nRF_USB-port (not the port that is normally used), and then setting the switch "nRF power source" to "USB".

As specified in the Objetive Product Specification, the voltage on VDDH should be between 2.5 and 5.5 V.

On the PDK, the VDDH voltage can be measured on P20, pin "VDD nRF HV".

RE: pca10056 vddio and REGOUT0 setting

FormerMember — Tue, 20 Jun 2017 10:34:24 GMT

Okay, from what I understand, VDD is 3.0 V. The measured 1.8 V, is it only for some, or on all GPIOs?

If you read the UICR settings for EXTSUPPLY and REGOUT0 using nrfjprog, what are their values?

RE: pca10056 vddio and REGOUT0 setting

Julie H — Mon, 19 Jun 2017 14:38:44 GMT

Kristin - Nope, still open! On the PDK, the VDD pins on the various headers all have 3.0 volts, and the UICR is configured for 3.0 volts. I'm unclear how I could be seeing 1.8 volts for "Logic High" on a GPIO pin with those configurations.

I have wondered if the VDDH pin on the nRF52840 having 1.8 volts might cause this, but I've not found a test point that would allow me to measure what VDDH happens to be going into the chip itself.

RE: pca10056 vddio and REGOUT0 setting

endnode — Mon, 19 Jun 2017 13:55:16 GMT

Not really, I'm afraid my answer was not accepted as correct;)

RE: pca10056 vddio and REGOUT0 setting

FormerMember — Mon, 19 Jun 2017 13:52:08 GMT

I guess this one is solved?

RE: pca10056 vddio and REGOUT0 setting

Julie H — Mon, 19 Jun 2017 13:39:41 GMT

Oh, gee, thanks! My initial thoughts were the UICR was set up for 1.8 volts. No! Too simple!

RE: pca10056 vddio and REGOUT0 setting

endnode — Mon, 19 Jun 2017 13:37:48 GMT

Well it's still Monday and Nordic guys are around;) I guess that's the price for submitting such nice corner case questions. If you would submit some usual "my BLE doesn't work please tell me why" as majority of people here you would get answers sooner;))))

RE: pca10056 vddio and REGOUT0 setting

Julie H — Mon, 19 Jun 2017 13:20:42 GMT

Yeah, I was hoping they would respond over the weekend ;)

I'm going to pour over the errata today. I was hoping to get an answer before this morning so I could fix my development circuit this weekend.

RE: pca10056 vddio and REGOUT0 setting

endnode — Sun, 18 Jun 2017 10:24:32 GMT

Oh so I've misunderstood an it's the other way around. Let's wait for Nordic guys, they will reply on Monday;)

RE: pca10056 vddio and REGOUT0 setting

Julie H — Sat, 17 Jun 2017 17:33:08 GMT

The GPIO pins definitely don't have a high reference voltage of VDD, which is 3.0 volts. Here's the problematic text --

GPIO levels

The GPIO high reference voltage always equals the level on the VDD pin.

In normal voltage mode, the GPIO high level equals the voltage supplied to the VDD pin, and in high voltage mode it equals the level specified in the register REGOUT0 listed in UICR — User information configuration registers.

RE: pca10056 vddio and REGOUT0 setting

endnode — Sat, 17 Jun 2017 15:31:44 GMT

Hi Julie,

From what I see in nRF52840 OBS changing EXTSUPPLY and REGOUT0 registers make sense only in "high voltage mode". Are you sure you run the chip in that configuration? I actually doubt as this mode should not support 1.8V (at least that's what power fail comparator suggests).

Cheers Jan