RM57L843: Bootloader erase flash using F021 API, but the contents are not all 0xff?

Hello TI engineer:

The bootloader uses the F021 flash library to program or erase the flash.

When I finished erasing a flash location, we don't see all locations have 0xFF's, some other bits in the erase flash locations are zeros.

from TMS570LC4357: Erasing Flash using F021 Flash API library doesn't show all the erased flash locations as 0xFFFFFFFF - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

I understand that it could be due to the flash ECC issue but not sure which function to call for enabling ECC or autogenerate ECC when erasing flash using the F021 library.

In bootloader program, I used API Fapi_issueAsyncCommandWithAddress(,FlashStartAddress) to earse the flash, and API Fapi_issueProgrammingCommand(, , ,NULL,0u,Fapi_AutoEccGeneration) to program the flash.

I don't program all the sector of flash, but I CRC check the entire flash. So when the address can be programmed, the value isn't 0xff. And CRC check found fault.

Please let me know if how can I solve the problem.