Rainbow Electronics AT89C5131 - Manual (Page 147)

147
AT89C5131
4136A–USB–03/03
Registers Table 99. PCON Register
PCON (S:87h)
Power Control Register
Reset Value = 10h
7 6 5 4 3 2 1 0
SMOD1 SMOD0 - POF GF1 GF0 PD IDL
Bit Number
Bit
Mnemonic Description
7 SMOD1
Serial Port Mode bit 1
Set to select double baud rate in mode 1, 2 or 3.
6 SMOD0
Serial Port Mode bit 0
Set to select FE bit in SCON register.
Clear to select SM0 bit in SCON register
5 -
Reserved
The value read from this bit is always 0. Do not set this bit.
4 POF
Power-Off Flag
Set by hardware when V
CC
rises from 0 to its nominal voltage. Can also be set by
software.
Clear to recognize next reset type.
3 GF1
General-purpose Flag 1
Set by software for general-purpose usage.
Cleared by software for general-purpose usage.
2 GF0
General-purpose Flag 0
Set by software for general-purpose usage.
Cleared by software for general-purpose usage.
1 PD
Power-down mode bit
Set this bit to enter in power-down mode.
Cleared by hardware when reset occurs.
0 IDL
Idle mode bit
Set this bit to enter in Idle mode.
Cleared by hardware when interrupt or reset occurs.