at89c5131 ATMEL Corporation, at89c5131 Datasheet - Page 33

• Manufacturer Part Number: at89c5131
• Description: 8-bit Flash Microcontroller With Full Speed Usb Device At89c5131
• Manufacturer: ATMEL Corporation

Hardware Security
4136C–USB–04/05
The following procedure is used to program the Hardware Security space and is sum-
marized in Figure 17:
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Figure 17. Hardware Programming Procedure
Set FPS and map Hardware byte (FCON = 0x0C)
Disable the interrupts.
Load DPTR at address 0000h.
Load Accumulator register with the data to load.
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.
Enable the interrupts.
Exec: MOVX @DPTR, A
Launch Programming
End Programming
Programming
Flash Spaces
FCON = 54h
FCON = A4h
Erase Mode
FCON = 00h
FCON = 0Ch
DPTR = 00h
ACC = Data
Data Load
Cleared?
Disable IT
Enable IT
FBusy
EA = 0
EA = 1
AT89C5131
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