Author: TakashiM_61 Version: **
When the firmware in flash memory is upgraded, the flash memory needs to be erased once before re-writing the new firmware into flash. The Flash Erase (All Sector Batch Erase) command can be used to erase all sectors in flash.
However, the CR trimming data is stored in the flash memory for all FM0+, FM3, and FM4 family microcontrollers. Therefore, if the entire flash memory is erased by the Flash Erase command, the CR trimming data is erased, too.
The CR trimming data is located at different addresses depending on the device. Refer to the Flash Programming Manual and datasheet for each device for check the CR trimming data location.
See the datasheet and flash guides: