AT89C51RD2-RDTIM Atmel, AT89C51RD2-RDTIM Datasheet - Page 101

• Manufacturer Part Number: AT89C51RD2-RDTIM
• Description: MCU 8-Bit AT89 80C51 CISC 64KB Flash 3.3V/5V 64-Pin VQFP Tray
• Manufacturer: Atmel

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
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