HT85F2270 datasheet(37/226 Pages) HOLTEK

tên linh kiện	HT85F2270

Giải thích chi tiết về linh kiện	Standard 8051 8-Bit Flash MCU

PDF	226 Pages

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nhà sản xuất	HOLTEK [Holtek Semiconductor Inc]

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Rev. 1.00

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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 bảng dữ liệu(PDF) 37 Page - Holtek Semiconductor Inc