mc68hc908lb8 Freescale Semiconductor, Inc, mc68hc908lb8 Datasheet - Page 38

• Manufacturer Part Number: mc68hc908lb8
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Memory
In applications that need more than 1000 program/erase cycles, use the 4-ms page erase specification
to get improved long-term reliability. Any application can use this 4-ms page erase specification.
However, in applications where a FLASH location will be erased and reprogrammed less than 1000 times,
and speed is important, use the 1-ms page erase specification to get a shorter cycle time.
2.6.3 FLASH Mass Erase Operation
Use this step-by-step procedure to erase entire FLASH memory to read as logic 1:
1. When in monitor mode, with security sequence failed (see
38
10. After a time, t
of any FLASH address.
1. Set the ERASE bit, and clear the MASS bit in the FLASH control register.
2. Read the FLASH block protect register.
3. Write any data to any FLASH location within the address range of the block to be erased.
4. Wait for a time, t
5. Set the HVEN bit.
6. Wait for a time, t
7. Clear the ERASE bit.
8. Wait for a time, t
9. Clear the HVEN bit.
1. Set both the ERASE bit and the MASS bit in the FLASH control register.
2. Read from the FLASH block protect register.
3. Write any data to any FLASH address
4. Wait for a time, t
5. Set the HVEN bit.
6. Wait for a time, t
7. Clear the ERASE and MASS bits.
8. Wait for a time, t
Programming and erasing of FLASH locations cannot be performed by
code being executed from FLASH memory. While these operations must be
performed in the order shown, other unrelated operations may occur
between the steps.
Be aware that erasing the vector page will erase the internal oscillator trim
value at $FFC0.
It is highly recommended that interrupts be disabled during program/ erase
operations.
Mass erase is disabled whenever any block is protected (FLBPR does not
equal $FF).
RCV
NVS
Erase
NVH
NVS
MErase
NVHL
(typical 1 µs), the memory can be accessed again in read mode.
(minimum 10 µs)
(minimum 10 µs)
(minimum 5 µs)
(minimum 1 ms or 4 ms)
(minimum 100 µs)
(minimum 4 ms)
MC68HC908LB8 Data Sheet, Rev. 1
(1)
CAUTION
within the FLASH memory address range.
NOTE
NOTE
19.3.2
Security), write to the FLASH block protect register instead
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