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Rev. 1.00
4� of ���
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Standard 8051 8-Bit Flash MCU
HT85F2260/HT85F2270/HT85F2280
Flash Program Memory
Flash Program Memory
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
0FFH
P�og�am Secto� N is not p�otected
Can be e�ased and p�og�ammed.
Can be �ead b�
flash control registers
�elated to the IAP and OCDS
(note)
and
the MOVC inst��ctions.
0FFH
Othe� val�es
except 0FFH
Secto� N is inhibited f�om P�og�amming/E�asing
Can not be e�ased and p�og�ammed b� the
ICP or flash control registers
�elated to the OCDS
(note)
.
Can be e�ased and p�og�ammed b�
flash control registers
�elated to the IAP.
Can be �ead b�
flash control registers
�elated to the IAP and the MOVC
inst��ctions.
Othe� val�es
except 0FFH
X
Secto� N is inhibited f�om P�og�amming/E�asing/Accessing (inst��ction fetch
is still allowed)
Can not be e�ased and p�og�ammed b� the
ICP or flash control registers
�elated to the IAP and OCDS
(note)
.
Can not be �ead b� the
ICP or flash control registers
�elated to the IAP and
OCDS
(note)
and the MOVC inst��ctions.
Note:
He�e “OCDS” stands fo� exec�ting OCDSINSTR inst��ction when in the OCDS mode.