Rainbow Electronics AT89C5131 - Manual (Page 32)

32
AT89C5131
4136A–USB–03/03
Hardware Security The following procedure is used to program the Hardware Security space and is sum-
marized in Figure 17:
• 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.
Figure 17. Hardware Programming Procedure
Flash Spaces
Programming
Disable IT
EA = 0
Launch Programming
FCON = 54h
FCON = A4h
End Programming
Enable IT
EA = 1
FBusy
Cleared?
Erase Mode
FCON = 00h
Data Load
DPTR = 00h
ACC = Data
Exec: MOVX @DPTR, A
FCON = 0Ch