MC908JL3ECPE Datasheet, PDF (30/180 Pages) Freescale Semiconductor, Inc – Microcontrollers

Memory
2.8 Flash Page Erase Operation
Use the following procedure to erase a page of Flash memory. A page consists of 64 consecutive bytes
starting from addresses $XX00, $XX40, $XX80 or $XXC0. The 48-byte user interrupt vectors area also
forms a page. Any page within the 4K bytes user memory area ($EC00–$FBFF) can be erased alone.
The 48-byte user interrupt vectors cannot be erased by the page erase operation because of security
reasons. Mass erase is required to erase this page.
1. Set the ERASE bit and clear the MASS bit in the Flash Control Register.
2. Write any data to any Flash address within the page address range desired.
3. Wait for a time, t_nvs (10μs).
4. Set the HVEN bit.
5. Wait for a time t_Erase (1ms).
6. Clear the ERASE bit.
7. Wait for a time, t_nvh (5μs).
8. Clear the HVEN bit.
9. After time, t_rcv (1μs)_, the memory can be accessed in read mode again.
NOTE
Programming and erasing of Flash locations cannot be performed by code
being executed from the Flash memory. While these operations must be
performed in the order as shown, but other unrelated operations may occur
between the steps.
2.9 Flash Mass Erase Operation
Use the following procedure to erase the entire Flash memory:
1. Set both the ERASE bit and the MASS bit in the Flash Control Register.
2. Write any data to any Flash location within the Flash memory address range.
3. Wait for a time, t_nvs (10μs).
4. Set the HVEN bit.
5. Wait for a time t_MErase (4ms).
6. Clear the ERASE bit.
7. Wait for a time, t_nvh1 (100μs).
8. Clear the HVEN bit.
9. After time, t_rcv (1μs)_, the memory can be accessed in read mode again.
NOTE
Programming and erasing of Flash locations cannot be performed by code
being executed from the Flash memory. While these operations must be
performed in the order as shown, but other unrelated operations may occur
between the steps.
MC68HC908JL3E Family Data Sheet, Rev. 4
30
Freescale Semiconductor