Setting UICR in nrf51822 and S110

[komuro]

What is the UICR setting in nrf51822,S110?

Currently, when I develop with nrf51822,S110, the UICR area is 0xFF.
I want to set the UICR as follows, is there any way to set it?
　I'm using keil as my development environment.
　CLENR0 : 0x18000
　XTALFREQ : 0x00

By the way, I was able to change XTALFREQ in SystemInit in system_nrf51.c, but I couldn't change CLENR0 even though I implemented it in the same way.

[Vidar Berg]

Hello,

I'm not sure why you are able to write the XTALFREQ setting in UICR, but not CLENR0. However, I would not recommend using CLENR0 if you are using DFU as it will prevent DFU to a larger Softdevice. From the bootloader documentation:

If the register UICR.CLENR0 has a size value (for example 0x00016000) and you are updating the SoftDevice, the new SoftDevice must not be larger than the current SoftDevice.

Also, note that we have PAN for the 32 MHz crystal. Please refer to PAN #78 here nRF51822 Product Anomaly Notification v3.3 for details.

Best regards,

Vidar