VCVT.F32.S32 seems to cause infinite CPU load consumption (~7mA)

[ThierryQ]

Dear Nordic,

We have a very strange issue regarding NRF52 consumption. We found that the NRF52 will continously consume 7mA even when we enter in sd_app_evt_wait(). After investigation, we found this issue happen once VCVT.F32.S32 ASM instruction is called. We would like to know where come from this issue exactly and understand what's wrong.

To reproduce it:

1. Open "ble_app_beacon" example code provided in the official SDK v12

2. Add 2 below lines in your main() just before for(;;):

   //volatile to avoid compiler optimization volatile int16_t aa = 1; volatile double measure = aa/((float)480.0); //Will invoke VCVT.F32.S32

   // Enter main loop. for (;; ) { if (NRF_LOG_PROCESS() == false) { power_manage(); } }

Now run this sample. You should observe that the board will consume 6.5mA for ever and will never going back to 100uA as expected.

Keil version: 5.22.0 (Latest)

NRF5 SDK version: 12.1 (Latest)

Board version: NRF528322 QFAAB0 V1.1.1 (2016.35)

Any help would be appreciate.

Thank you,

Best regards,

Thierry

[Wojtek]

I am not sure, but it looks like this for me.

[ThierryQ]

Thank you it works !