AT89C51ID2-SMSIM ATMEL [ATMEL Corporation], AT89C51ID2-SMSIM Datasheet - Page 125

• Manufacturer Part Number: AT89C51ID2-SMSIM
• Description: 8-bit Flash Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

Boot Process
Figure 49. Bootloader Process
4289A–8051–09/03
USER APPLICATION
PC=0000h
ENBOOT=0
BLJB=1
USER BOOT LOADER
PC= [SBV]00h
BSB = 00h
SBV = FCh
FCON = 00h
condition?
Hardware
BLJB!= 0
RESET
?
?
?
?
F800h
If BLJB=0 then ENBOOT bit (AUXR1) is set
BLJB=0
ENBOOT=1
FCON = F0h
Yes (PSEN = 0, EA = 1, and ALE =1 or not connected)
FCON = 00h
yes = hardware boot
else ENBOOT bit (AUXR1) is cleared
Atmel BOOT LOADER
conditions
AT89C51ID2
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