AT89C51RE2 Atmel Corporation, AT89C51RE2 Datasheet - Page 121

• 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

Registers
7663E–8051–10/08
Table 89. PCON Register
PCON (87:h) Power configuration Register
Reset Value= XXXX 0000b
Bit Number
SMOD1
7
7
6
5
4
3
2
1
0
Mnemonic
SMOD0
SMOD1
SMOD0
POF
GF1
GF0
Bit
IDL
PD
6
-
Description
Serial Port Mode bit 1
Set to select double baud rate in mode 1, 2 or 3.
Serial Port Mode bit 0
Cleared to select SM0 bit in SCON register.
Set to select FE bit in SCON register.
reserved
Power-Off Flag
Cleared to recognize next reset type.
Set by hardware when VCC rises from 0 to its nominal voltage. Can also be set by
software.
General Purpose flag 1
One use is to indicate whether an interrupt occurred during normal operation or during
Idle mode.
General Purpose flag 0
One use is to indicate whether an interrupt occurred during normal operation or during
Idle mode.
Power-Down Mode bit
Cleared by hardware when an interrupt or reset occurs.
Set to activate the Power-Down mode.
If IDL and PD are both set, PD takes precedence.
Idle Mode bit
Cleared by hardware when an interrupt or reset occurs.
Set to activate the Idle mode.
If IDL and PD are both set, PD takes precedence.
5
-
POF
4
GF1
3
GF0
2
AT89C51RE2
PD
1
IDL
0
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