https://devzone.nordicsemi.com/f/nordic-q-a/76722/how-to-force-nrf52840-with-cortex-m4-to-have-precise-bus-errorHey! From this link it says one can force the cortex-m4 to disable write buffering. This is supposed to remove imprecise bus errors. To do this i write 1 to bit 1 in the ACTLR using this code However I still get imprecise bus errors and cant finden-USTelligent Community 13Thu, 24 Jun 2021 14:02:21 GMThttps://devzone.nordicsemi.com/thread/317038?ContentTypeID=1Thu, 24 Jun 2021 14:02:21 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a782cdea-4660-4bc0-81a5-9ada68fd006fVidar Berg<p>Hello,</p> <p>This may not be very helpful, but I was able to go from a imprecise busfault to a precise busfault after I added your code to my main().</p> <p>Crash log before setting the DISDEFWBUF bit:</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1624543195401v1.png" alt=" " /></p> <p>And after:</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1624543230462v2.png" alt=" " /></p> <p>Code triggering the bus fault in both cases:</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1624543272188v3.png" alt=" " /></p> <p>Maybe it could be worth checking if the DISDEFWBUF bit is still set after the fault exception is raised?</p><div style="clear:both;"></div>