AT89C51RE2 Atmel Corporation, AT89C51RE2 Datasheet - Page 49

• Manufacturer Part Number: AT89C51RE2
• Manufacturer: Atmel Corporation

Specifications of AT89C51RE2

• Flash (kbytes): 128 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Spi: 1
• Uart: 2
• Sram (kbytes): 8.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART/OCD
• Watchdog: Yes

Fuse ConfigurationByte
7663E–8051–10/08
Figure 18. HSB Reading Procedure
The following procedure is used to read the Fuse Configuration byte and is summarized
in Figure 18:
•
•
•
HSB Reading Procedure
Map the FCB by writing 05h in FCON register.
Read the byte in Accumulator by executing MOVC A,@A+DPTR with A= 0 & DPTR= 0000h.
Clear FCON to unmap the Hardware Security Byte.
Exec: MOVC A, @A+DPTR
Exec: MOVC A, @A+DPTR
FCON = 00h (FPS = 0)
FCON = 00h (FPS = 0)
HSB Unmapping
HSB Unmapping
HSB Reading
FCB Reading
HSB Mapping
FCB Mapping
DPTR= 0000h
DPTR= 0000h
FCON = 04h
FCON = 05h
Data Read
Data Read
ACC= 00h
ACC= 00h
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