mc68hc908gr8a Freescale Semiconductor, Inc, mc68hc908gr8a Datasheet - Page 40

• Manufacturer Part Number: mc68hc908gr8a
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Memory
2.6.3 FLASH Page Erase Operation
Use this step-by-step procedure to erase a page (64 bytes) of FLASH memory. A page consists of 64
consecutive bytes starting from addresses $XX00, $XX40, $XX80, or $XXC0. The 36-byte user interrupt
vectors area also forms a page. Any FLASH memory page can be erased alone.
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.
2.6.4 FLASH Mass Erase Operation
Use this step-by-step procedure to erase entire FLASH memory:
1. When in monitor mode, with security sequence failed (see
40
10. After a time, t
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 page 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 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
9. Clear the HVEN bit.
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.
Mass erase is disabled whenever any block is protected (FLBPR does not
equal $FF).
RCV
RCV
NVS
Erase
NVH
NVS
MErase
NVHL
(typical 1 μs), the memory can be accessed in read mode again.
(typical 1 μs), the memory can be accessed in read mode again.
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
(minimum 10 μs)
(minimum 10 μs)
(minimum 5 μs)
(minimum 1 ms or 4 ms)
(minimum 100 μs)
(minimum 4 ms)
(1)
within the FLASH memory address range.
NOTE
NOTE
18.3.2
Security), write to the FLASH block protect register instead
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