FICR Register Production Release Variant

[ChroukK]

Hi,

We have ordered nr51822 chips in the past. Recently, we made a new purchase and on programming we have discovered that the FICR register information is different for this purchase than previous ones: 

- Older orders : nRF51822 QFAC A1 - has FICR: 0x84

- Newer orders: nRF51822 QFAC A0 - has FICR: 0x83

The last two digits correspond to the build code. In build code, 0..9 is for production release. In the reference manual, this difference corresponds to <P> "Production Device Identifier".  What does that mean? We have two concerns: 

1- What is the difference between two production releases in build code (0 and 1)? How significant is the difference? Are there any compatibility concerns with software (SDK and SoftDevice)?

2- Can we make orders where we ask for a specific production release (A0)? 

We would like to evaluate the difference between both variants. If any, we would like to accommodate for this difference in our production processes and future purchases.

Thanks! 

[Jørgen Holmefjord]

Hi,

The only difference between these build codes is the assembly facility, see the table in PCN099 Product Change Notification v1.0.

Both chips is the same revision of the chip, and has wafer from the same factory. They are tested and verified using the same testes, so there should not be any compatibility issues with SDK or Softdevice versions.

If you have a requirement to receive only one version, you should check with your distributor or regional sales manager if this is something that can be arranged, but it should not be necessary.

Best regards,
Jørgen

[Jørgen Holmefjord]

In general, you can find information about the different variants in the nRF51822 IC revisions and variants compatibility matrix.

I'm not familiar with any of the nR51822 QFAC build codes you mention, where did you find these? If it follows the same pattern as nRF52 series, AA0 and AB0 could be engineering variants of the revision, but I cannot say anything specific without a reference to where you have these from. Anyway, I would not worry about receiving other variants than Ax0 of this chip.

[ChroukK]

I found them in the nrf51deviceids.xml in the path of nRFGo Studio. What are engineering variants? Does it entail a difference in the design?

Also, the PCN099 Product Change Notification v1.0 states there is an A20 build code for nRF51822 QFAC too, but I can't find the corresponding HWID? where can I find the information of the mapping of the HWID to the hardware info. We are looking at nrf51deviceids.xml, but we are looking for a known central source of information. 

[Jørgen Holmefjord]

Engineering variants are the chips used for preview/evaluation/development before the production variant of the chip is available.

Unfortunately, we do not have a public list of HWIDs available for nRF51. What information do you get from this that you can't get from the nrf_ic_info_get() function?

According to PCN106 Product Change Notification v1.0, there is also a A30 build code available.

[ChroukK]

To answer your question on what information do we get from a public list: we get to know the id beforehand without having the ic, and allow for that specific id on production. Currently with nrf_ic_info_get() function, we need the chip of this particular variant to readout the HWID. Are there other ways we can know the HWID's without getting IC's of different variants? 

Thanks for alerting us of a PN106 for A30 build code too!