Flash MemoryMPC5566 Microcontroller Reference Manual, Rev. 2Freescale Semiconductor 13-31NOTELock and Select are independent. If a block is selected and locked, no eraseoccurs. Refer to Section 13.3.2.2, “Low/Mid Address Space Block LockingRegister (FLASH_LMLR), Section 13.3.2.3, “High Address Space BlockLocking Register (FLASH_HLR)” and Section 13.3.2.4, “SecondaryLow/Mid Address Space Block Locking Register (FLASH_SLMLR)” formore information.3. Write to any address in flash. This is referred to as an erase interlock write.4. Write a logic 1 to the FLASH_MCR[EHV] bit to start an internal erase sequence or skip to step 9to terminate.5. Wait until the FLASH_MCR[DONE] bit goes high.6. Confirm FLASH_MCR[PEG] = 1.7. Write a logic 0 to the FLASH_MCR[EHV] bit.8. If more blocks are to be erased, return to step 2.9. Write a logic 0 to the FLASH_MCR[ERS] bit to terminate the erase.The erase sequence is presented graphically in Figure 13-15. The erase suspend operation detailed inFigure 13-15 is discussed in section Section 13.4.2.4.1, “Flash Erase Suspend/Resume.”After settingFLASH_MCR[ERS], one write, referred to as an interlock write, must be performed beforeFLASH_MCR[EHV] can be set to a 1. Data words written during erase sequence interlock writes areignored. The user can terminate the erase sequence by clearing FLASH_MCR[ERS] before settingFLASH_MCR[EHV].An erase operation can be aborted by clearing FLASH_MCR[EHV] assuming FLASH_MCR[DONE] islow, FLASH_MCR[EHV] is high and FLASH_MCR[ESUS] is low. An erase abort forces the module tostep 8 of the erase sequence. An aborted erase results in FLASH_MCR[PEG] being set low, indicating afailed operation. The blocks being operated on before the abort contain indeterminate data. The usercannot abort an erase sequence while in erase suspend.WARNINGAborting an erase operation leaves the flash core blocks being erased in anindeterminate data state. This can be recovered by executing an erase on theaffected blocks.13.4.2.4.1 Flash Erase Suspend/ResumeThe erase sequence can be suspended to allow read access to the flash core. The erase sequence can alsobe suspended to program (erase-suspended program) the flash core. A program started during erasesuspend can in turn be suspended. Only one erase suspend and one program suspend are allowed at a timeduring an operation. It is not possible to erase during an erase suspend, or program during a programsuspend. During suspend, all reads to flash core locations targeted for program and blocks targeted forerase return indeterminate data. Programming locations in blocks targeted for erase duringerase-suspended program can result in corrupted data.
