MC908GR32AVFAE Datasheet, PDF (45/314 Pages) Freescale Semiconductor, Inc – Microcontrollers

FLASH-1 Memory (FLASH-1)
2.6.4 FLASH-1 Mass Erase Operation
Use this step-by-step procedure to erase the entire FLASH-1 memory:
1. Set both the ERASE bit and the MASS bit in the FLASH-1 control register (FL1CR).
2. Read the FLASH-1 block protect register (FL1BPR).
NOTE
Mass erase is disabled whenever any block is protected (FL1BPR does not
equal $FF).
3. Write to any FLASH-1 address within the FLASH-1 array with any data.
4. Wait for a time, t_NVS (minimum 10 μs).
5. Set the HVEN bit.
6. Wait for a time, t_MERASE (minimum 4 ms).
7. Clear the ERASE and MASS bits.
8. Wait for a time, t_NVHL (minimum 100 μs).
9. Clear the HVEN bit.
10. Wait for a time, t_RCV, (typically 1 μs) after which the memory can be accessed in normal read mode.
NOTE
A. Programming and erasing of FLASH locations can not be performed by code being executed from the
same FLASH array.
B. While these operations must be performed in the order shown, other unrelated operations may occur
between the steps. However, care must be taken to ensure that these operations do not access any
address within the FLASH array memory space such as the COP control register (COPCTL) at
$FFFF.
C. It is highly recommended that interrupts be disabled during program/erase operations.
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
Freescale Semiconductor
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