Question related to the FPU anomaly.

[MANGO]

[87] CPU: Unexpected wake from System ON Idle when using FPU

This anomaly applies to IC Rev. Rev 1, build codes QFAA-B00, QFAB-B00, CIAA-B00.

I have the PCA10040. While using the nRFgo Studio 1.21.2, I couldn't find the build-code of the MCU which is mounted on the PCA10040.

I read the code, which is written on the MCU, with my eyes. It was written as

N52832
QFAAB0
1612AP

0. So, in this case, does this MCU can show that anomaly?

1. If so, will there be a newly revised chip for nRF52832-QFAA which doesn't have this anomaly?

I'm on a project that requires the FPU. So I'm worried to work with the nRF52832.

-Best Regards

[endnode]

Hi,

A) There is a workaround for this anomaly mentioned in anomaly description so you CAN use FPU even if your chip revision is affected, just implement that code (I would actually bet it is already included in nRF5 SDK so check that if you use it).

B) If you see second row printed on your chip you can clearly see that you have "QFAA-B00" so this chip is affected. Link between 6-char/digit identifier on IC packaging and build code is pretty clearly explained at Nordic infocenter here.

Cheers Jan

[RichieJH]

Endnode has this answered below, but just to add don't worry about this anomaly. It is just the ARM Cortex having an FPU interrupt that needs to be cleared before calling sleep. Just add those lines per the note and sorted.