w79e532 Winbond Electronics Corp America, w79e532 Datasheet - Page 57

• Manufacturer Part Number: w79e532
• Description: 8-bit Microcontroller
• Manufacturer: Winbond Electronics Corp America

Example 4: Invalid access
Example 5: Invalid Access
In the first three examples, the writing to the protected bits is done before the 3 machine cycle window
closes. In Example 4, however, the writing to the protected bit occurs after the window has closed,
and so there is effectively no change in the status of the protected bit. In Example 5, the second write
to TA occurs 4 machine cycles after the first write, therefore the timed access window in not opened at
all, and the write to the protected bit fails.
MOV
MOV
NOP
NOP
CLR
MOV
NOP
MOV
SETB EWT
TA, #0AAh
TA, #055h
POR
TA, #0AAh
TA, #055h
3 M/C
3 M/C
1 M/C
1 M/C
2 M/C
3 M/C
1 M/C
3 M/C
2 M/C
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Publication Release Date: November 21, 2005
W79E532/W79L532
Revision A5