User Manual

36
T89C51AC2
Rev. B – 19-Dec-01
• Launc h the programming by writing the data sequence 52h followed by A2h in
FCON register (only from FM1 ).
The end of the programm ing indicated by the FBUSY flag cleared.
• En able the interrupts.
Figure 13. F lash and Extra row Programming Procedure
Hardware Security Byte
The following procedure is used to program the Hardware Security Byte space
and is summarized in Figure 14:
• Se t FPS and m ap Hardware by t e (FCON = 0x0C)
• Sa ve and di sa ble the interrupts.
• Load DPTR at address 0000h.
• Load Accumulator regist er with the data to load.
• Execute the MOVX @DPTR, A instruction.
• Launc h the programming by writing the data sequence 54h followed by A4h in
FCON register (only from FM1 ).
The end of the programm ing indicated by t he FBusy flag cleared.
• Res tore t he i nte rrupts
.
FLASH Spaces
Programming
Save & Disable IT
EA= 0
Launch Programming
FCON= 5xh
FCON= Axh
End Programming
Restore IT
Column Latches Loading
see Figure 12
FBusy
Cleared?
Clear Mode
FCON = 00h