M68HC08 datasheet(57/288 Pages) FREESCALE

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FLASH Memory

MC68HC908BD48 — Rev. 2.1

Data Sheet

Freescale Semiconductor

FLASH Memory

HVEN — High-Voltage Enable Bit

This read/write bit enables the charge pump to drive high voltages for

program and erase operations in the array. HVEN can only be set if

either PGM = 1 or ERASE = 1 and the proper sequence for program

or erase is followed.

1 = High voltage enabled to array and charge pump on

0 = High voltage disabled to array and charge pump off

MASS — Mass Erase Control Bit

Setting this read/write bit configures the 48,128 bytes FLASH array

for mass erase operation.

1 = Mass Erase operation selected

0 = Mass Erase operation not selected

ERASE — Erase Control Bit

This read/write bit configures the memory for erase operation. ERASE

is interlocked with the PGM bit such that both bits cannot be equal to

1 or set to 1 at the same time.

1 = Erase operation selected

0 = Erase operation not selected

PGM — Program Control Bit

This read/write bit configures the memory for program operation.

PGM is interlocked with the ERASE bit such that both bits cannot be

equal to 1 or set to 1 at the same time.

1 = Program operation selected

0 = Program operation not selected

4.5 FLASH Block Erase Operation

Use the following procedure to erase a block (512 bytes) of FLASH

memory:

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

2. Write any data to any FLASH address within the block address

range desired.

3. Wait for a time, tnvs (min. 5µs)

M68HC08 датащи(PDF) 57 Page - Freescale Semiconductor, Inc