HT85F2270 datasheet(45/226 Pages) HOLTEK

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Rev. 1.00

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Standard 8051 8-Bit Flash MCU

HT85F2260/HT85F2270/HT85F2280

These two types of flash memory inhibited bytes, SECURITY1[N] and SECURITY2[N], are used

for Program Memory protection. However, the SECURITY2[N] bytes have the higher priority. If

data has be written to the SECURITY2[N] bytes, the corresponding sectors will be protected and

cannot be read from or written to, no matter what data is in the SECURITY1[N] bytes. Note that

the Flash Memory protect function will not affect the instruction fetched by the MCU core. The

accompanying table illustrates the inhibited bytes priority.

SECURITY2[N] SECURITY1[N]

Privilege

0FFH

Program Sector N is not protected

Can be erased and programmed.

Can be read b� flash control registers related to the IAP and OCDS(note) and

the �OVC instructions.

0FFH

Other values

except 0FFH

Sector N is inhibited from Programming/Erasing

Can not be erased and programmed b� the ICP or flash control registers

related to the OCDS(note).

Can be erased and programmed b� flash control registers related to the IAP.

Can be read b� flash control registers related to the IAP and the �OVC

instructions.

Other values

except 0FFH

Sector N is inhibited from Programming/Erasing/Accessing (instruction fetch

is still allowed)

Can not be erased and programmed b� the ICP or flash control registers

related to the IAP and OCDS(note).

Can not be read b� the ICP or flash control registers related to the IAP and

OCDS(note) and the �OVC instructions.

Note: Here “OCDS” stands for executing OCDSINSTR instruction when in the OCDS mode.

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