HT85F2240 datasheet(33/147 Pages) HOLTEK

Il numero della parte	HT85F2240

Spiegazioni elettronici	A/D Flash 8051 Core Low Pin Count MCU

PDF	147 Pages

Scroll/Zoom	100%

Produttore elettronici	HOLTEK [Holtek Semiconductor Inc]

Homepage	http://www.holtek.com

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Rev. 1.10

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A/D Flash 8051 Core Low Pin Count MCU

HT85F2230/HT85F2240

Flash Memory Read/Write Operations

The flash memory can be read from and written to using register operations. To ensure protection

of application data certain protection measures have to be first carried out before any read and

write operations are executed on the Flash Memory.

Unlocking the Flash Memory

Before writing data to the Flash Memory it must first be unlocked. This is implemented by writing

a correct data sequence to the Flash Memory Unlock key register, FMKEY. It is recommended

to write the data sequence to the FMKEY register in 4 consecutive instructions. The following

flowchart illustrates the unlock procedure.

START

FMKEY = 0x��;

FMKEY = 0xAA;

FMKEY = 0x00;

FMKEY = 0xFF;

Bit UNLOCK is 1

For examp�e� 4 consec�tive

statements in C �ang�age

END

Bit UNLOCK is 0

F�ash memor� is in

�ocked state

F�ash memor� is in

�n�ocked state

Unlock Procedure Flowchart

HT85F2240 Scheda tecnica(PDF) 33 Page - Holtek Semiconductor Inc