Datasheet

48
AT89C51AC3
4383D–8051–02/08
Figure 25. Column Latches Loading Procedure
Note: The last page address used when loading the column latch is the one used to select the
page programming address.
Programming the Flash Spaces
User The following procedure is used to program the User space and is summarized in
Figure 26:
• Load up to one page of data in the column latches from address 0000h to FFFFh.
• Save and Disable the interrupts.
• Launch the programming by writing the data sequence 50h followed by A0h in
FCON register (only from FM1).
The end of the programming indicated by the FBUSY flag cleared.
• Restore the interrupts.
Extra Row The following procedure is used to program the Extra Row space and is summarized in
Figure 26:
• Load data in the column latches from address FF80h to FFFFh.
• Save and Disable the interrupts.
• Launch the programming by writing the data sequence 52h followed by A2h in
FCON register (only from FM1).
The end of the programming indicated by the FBUSY flag cleared.
• Restore the interrupts.
Column Latches
Loading
Data Load
DPTR = Address
ACC = Data
Exec: MOVX @DPTR, A
Last Byte
to load?
Column Latches Mapping
FCON = 08h (FPS=1)
Data memory Mapping
FCON = 00h (FPS = 0)
Save and Disable IT
EA = 0
Restore IT