at89c51rd2-smsum ATMEL Corporation, at89c51rd2-smsum Datasheet - Page 101

• Manufacturer Part Number: at89c51rd2-smsum
• Description: 8-bit Flash Microcontroller
• Manufacturer: ATMEL Corporation

24.6.5
Figure 24-5. Bootloader Process
4235J–8051–01/08
Boot Process
PC = 0000h
User Application
BLJB = 1
ENBOOT = 0
USER BOOT LOADER
PC= [SBV]00h
BSB = 00h
SBV = FCh
Condition?
Hardware
BLJB!= 0
RESET
?
?
?
If BLJB = 0 then ENBOOT Bit (AUXR1) is Set
BLJB = 0
ENBOOT = 1
Yes (PSEN = 0, EA = 1, and ALE =1 or Not Connected)
else ENBOOT Bit (AUXR1) is Cleared
Atmel BOOT LOADER
AT89C51RD2/ED2
101