nRF52840 INFO.VARIANT interpretation

[Shai-hulud]

I am trying to interpret the values in the INFO.VARIANT register for the nRF52840. The datasheet states "Build code (hardware version and production configuration). Encoded as ASCII." and gives some examples of the values, but not what characters corresponds to hardware version and production configuration. I could probably infere what they represent, but I need some confirmation on how to interpret the value.

Thank you,

[Jørgen Holmefjord]

Hi,

You can find this information in the IC revisions and variants Compatibility matrix. The INFO.VARIANT and INFO.PACKAGE register makes up the "Packet variant" and "Build code" fields from the matrix.

Best regards,
Jørgen

[Shai-hulud]

Hi Jørgen,

To confirm my interpretation of INFO.VARIANT, the register appears to be encoded as VVHP. Where VV is the function variant code (only AA is listed in data sheet), H is the hardware version (currently A, B, C, and D are released), and P is the production configuration code (0 to 9 for production release, A to Z for engineering release).

If I were to read the INFO.VARIANT register for the current production released part, would it read AAD0? If this is not correct can you please break down what the individual INFO.VARIANT register characters represent?

Thank you,

[Jørgen Holmefjord]

Yes, that is correct. My nRF52840 DK v1.1.0 with Rev 2 chip reads AAD0.

[ThierryC]

I still dont undersatand how to read it with these explainations. Build code is 3 letters, and there we have only 2 for the Hardware and Production.

[Shai-hulud]

As best I can tell the build code and INFO.VARIANT register are not very clearly defined in the Nordic documentation. 

The build code is only listed as 3 letters on the shipping container labels, see Table 174 of datasheet.

You can also see this in the Nordic PCN-111 (or in package marking section of datasheet) where the build code is clearly indicated as 3 letter on the package labeling and 2 letters on the chip marking. 

 

For INFO.VARIANT I had to guess what the other 2 of 4 characters represented, which the Function variant code seemed like a logical choice, since it was also on the package marking.

None of the values shown in the datasheet for INFO.VARIANT seem to correlate with any existing combination of released parts, which makes it very confusing to decipher what they actually represent.

Nordic rep,

Please correct me any of the above is wrong (I need to be sure that my understanding of INFO.VARIANT is correct).