Atmel 8051 User Manual

Common Features Description
Atmel 8051 Microcontrollers Hardware Manual 2-108
4316B–8051–02/04
Reset Value = 00X1 0000b
Not bit addressable
Power-off flag reset value will be 1 only after a power on (cold reset). A warm reset
doesn’t affect the value of this bit.
Bit
Number
Bit
Mnemonic Description
7SMOD1
Serial port Mode bit 1 for UART
Set to select double baud rate in mode 1, 2 or 3.
6SMOD0
Serial port Mode bit 0 for UART
Cleared to select SM0 bit in SCON register.
Set to select FE bit in SCON register.
5-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
4POF
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.
3GF1
General purpose Flag
Cleared by user for general purpose usage.
Set by user for general purpose usage.
2GF0
General purpose Flag
Cleared by user for general purpose usage.
Set by user for general purpose usage.
1PD
Power-Down mode bit
Cleared by hardware when reset occurs.
Set to enter power-down mode.
0IDL
Idle mode bit
Cleared by hardware when interrupt or reset occurs.
Set to enter idle mode.
76543210
- - - BRR TBCK RBCK SPD SRC

Atmel 8051 Specifications

General

Brand	Atmel
Model	8051
Category	Microcontrollers
Language	English