Xeltek, a programmer manufacture, is developing programmer for MC56F84550. They found that after send mass erase command (FTFA, mass erase command) the MCU will be locked.
We try to execute erase all blocks command, then modify the flash control block, but the chip still can't unlock.
Before modify flash control block, we try the following two ways to judge whether the Flash erase is finished.
(1) Time delay, then modify the flash control block.
(2) Read FSTAT register to judge whether the erase is finished, but the readout register is always 0. Then modify the flash control block.
Whether the operation is right? if not, If there are other ways to unlock MC56F84550?