at89c51re2-slsem ATMEL Corporation, at89c51re2-slsem Datasheet - Page 44

• Manufacturer Part Number: at89c51re2-slsem
• Description: At89c51re2 8-bit Flash Microcontroller
• Manufacturer: ATMEL Corporation

Fuse Configuration Byte (FCB)
44
AT89C51RE2
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Figure 6. Hardware Security Byte Programming Procedure
The following procedure is used to program the Fuse Configuration Byte space
and is summarized in Figure 7:
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Execute the MOVX @DPTR, A instruction.
Launch the programming by writing the data sequence 54h followed by A4h in
FCON register.
The end of the programming indicated by the FBusy flag cleared.
Restore the interrupts
Set FPS and map FCB (FCON = 0x0D)
Save and disable the interrupts.
Load DPTR at address 0000h
Load Accumulator register with the data to load.
Execute the MOVX @DPTR, A instruction.
Launch Programming
Exec: MOVX @DPTR, A
End Programming
Save & Disable IT
Programming
FCON = 00h
FCON= 54h
FCON= A4h
Clear Mode
Cleared?
FCON = 0Ch
RestoreIT
DPTR= 00h
ACC= Data
Data Load
FBusy
HSB
EA= 0
7663B–8051–03/07