Datasheet

FLASH Memory (FLASH)

MC68HC908LJ12 — Rev. 2.1 Technical Data

Freescale Semiconductor FLASH Memory (FLASH) 63

4.4 FLASH Control Register

The FLASH control register (FLCR) controls FLASH program and erase

operations.

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

This read/write bit configures the memory for mass erase operation or

block erase operation when the ERASE bit is set.

1 = Mass Erase operation selected

0 = Block Erase operation 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

Address: $FE08

Bit 7654321Bit 0

HVEN MASS ERASE PGM

Write:

Reset:00000000

Figure 4-2. FLASH Control Register (FLCR)