HT85F2270 datasheet(37/226 Pages) HOLTEK

Il numero della parte	HT85F2270

Spiegazioni elettronici	Standard 8051 8-Bit Flash MCU

PDF	226 Pages

Scroll/Zoom	100%

Produttore elettronici	HOLTEK [Holtek Semiconductor Inc]

Homepage	http://www.holtek.com

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Standard 8051 8-Bit Flash MCU

HT85F2260/HT85F2270/HT85F2280

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

F�KEY = 0x��;

F�KEY = 0xAA;

F�KEY = 0x00;

F�KEY = 0xFF;

Bit UNLOCK is 1

For example� 4 consecutive

statements in C language

END

Bit UNLOCK is 0

Flash memor� is in

locked state

Flash memor� is in

unlocked state

Unlock Procedure Flowchart

HT85F2270 Scheda tecnica(PDF) 37 Page - Holtek Semiconductor Inc