Freescale Semiconductor, Inc.
Flash Memory
Erasing the Flash EEPROM
START ERASE
TURN ON VFP
CLEAR MARGIN FLAG
CLEAR ERASE PULSE COUNTER (nEP
)
WRITE PPAGE
SET ERAS
SET LAT
WRITE TO ARRAY
SET ENPE
DELAY FOR DURATION
OF ERASE PULSE
(tEPULSE
)
CLEAR ENPE
SET
MARGIN FLAG
DELAY BEFORE VERIFY
(tVERASE
)
INCREMENT
IS
n
EP COUNTER
MARGIN FLAG
SET?
READ
ARRAY
NO
YES
DECREMENT
ARRAY
ERASED?
nEP COUNTER
YES
NO
NO
nEP = 0?
YES
nEP = 5?
YES
NO
ARRAY
ERASED?
NO
YES
CLEAR LAT
TURN OFF VFP
ARRAY ERASED
ARRAY FAILED TO ERASE
Figure 7-2. Erase Sequence Flow
MC68HC912DG128 — Rev 3.0
Technical Data
Flash Memory
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