We enabled the ECC in bootloader and application, these days we have ESM group 3 channel 7 error(FMC uncorrectable error). We checked this link https://e2e.ti.com/support/microcontrollers/hercules/f/312/t/588269?RM48L952-Migration-from-RM44-causes-occasional-ESM-group-3-channel-7-errors-speculative-fetch. By fully programmed the whole ROM (with IAR IDE I used "linker->checksum->fill pattern 0xFFFFFFFF, fill ADDRESS from 0 to 0x001FFFFF") , we see this uncorrectable is gone. But one of my colleagues still catch the group 1 channel 6 error (FMC correctable error). We don't understand why he still get the error after filling the whole ROM.