Errata 216 that not affect nrf52840

Question

Hello, 
 as part of my tries to use xip on nrf52840, I found that using the entire program on the external flash is impossible due to Errata 216 . 
 I check the FICR for my MCU INFO.PART , INFO.VARIANT and INFO.PACKAGE . the results are 52840, QI AAC0 - and as I see in the errata, I guess it is the specific variant that has the problem (if I'm wrong please let me know). 
 My main question is if the other variants of nrf52840 are able to use xip in such a way that I can put my program on the external flash. 
 Thanks, Udi.

AHaug · Accepted Answer

Hi, 
 The nRF52840 has hardware support for XiP, but due to Errata 215 and 216, which you referred to, the support is severely limited for the nRF52840 w.r.t XiP. In nRF Connect SDK there is no support for XiP for the nRF52840. 
 In general if you wish to attempt to develop something proprietary, you must also be aware of other considerations in addition to the limitations caused by the erratas and the lack of support for XiP on the nRF52840 in NCS. 
 You must design your code so that you have full control over all entry points to code that should be ran from an external flash or not. Code that should not run on external flash is anything timing criticial such as for instance anything depending on interrupts. Do also note that XiP applications that is battery driven is not recommended due to the increase in current consumption. 
 Kind regards, Andreas