AT89C51RD2 Atmel Corporation, AT89C51RD2 Datasheet - Page 101

• Manufacturer Part Number: AT89C51RD2
• Manufacturer: Atmel Corporation

Specifications of AT89C51RD2

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Uart: 1
• Sram (kbytes): 2
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

24.6.5
Figure 24-5. Bootloader Process
4235K–8051–05/08
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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