AT89C51RE2 Atmel Corporation, AT89C51RE2 Datasheet - Page 34

• 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 Configuration Byte
(FCB)
34
AT89C51RE2
The Fuse configuration byte is a part of FM0.
The 8 bits read/written by software (from FM0 or RM0) and written by hardware in parallel mode.
Table 20. Fuse Configuration Byte (FCB)
Number
Bit
6-3
2-0
X2
7
7
Mnemonic
BRV2-0-
Bit
X2
-
6
-
Description
X2 Mode
Unused
Boot Reset Vector
These bits allow to configure the reset vector of the product according to the following
values:
1 1 1: Reset at address 0x0000 of FM0 with Bank0 mapped
1 1 0: Reset at address 0xFFFC of Bank 0
1 0 1: Reset at address 0xFFFC of Bank 1
1 0 0: Reset at address 0xFFFC of Bank 2
0 1 1: Reset at address 0x0000 of RM0 (Internal ROM bootloader execution)
0 1 0: Reserved for further extension but same as 1 1 1
0 0 1: Reserved for further extension but same as 1 1 1
0 0 0: Reserved for further extension but same as 1 1 1
5
Programmed (‘0’ value) to force X2 mode (6 clocks per instruction) after reset
Unprogrammed (‘1’ value) to force X1 mode, Standard Mode, after reset (Default)
-
4
-
3
-
BRV2
2
BRV1
1
7663E–8051–10/08
BRV0
0