M68HC08 datasheet(62/332 Pages) FREESCALE

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FLASH Memory

Technical Data

MC68HC908JB16 — Rev. 1.1

FLASH Memory

Freescale Semiconductor

4.5 FLASH Block Erase Operation

Use the following procedure to erase a block of FLASH memory. A block

consists of 512 consecutive bytes starting from addresses $X000,

$X200, $X400, $X600, $X800, $XA00, $XC00 or $XE00. The 48-byte

user interrupt vectors area also forms a block. Any block within the 16K

bytes user memory area ($BA00–$F9FF) can be erased alone.

NOTE:

The 48-byte user interrupt vectors, $FFD0–$FFFF, cannot be erased by

the block erase operation because of security reasons. Mass erase is

required to erase this block.

1. Set the ERASE bit and clear the MASS bit in the FLASH control

2. Write any data to any FLASH address within the address range of

the block to be erased.

3. Wait for a time, tnvs (5µs).

4. Set the HVEN bit.

5. Wait for a time tErase (10ms).

6. Clear the ERASE bit.

7. Wait for a time, tnvh (5µs).

8. Clear the HVEN bit.

9. After time, trcv (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.

M68HC08 Datasheet(PDF) 62 Page - Freescale Semiconductor, Inc