Table 36. PCON Register
PCON (S:87h)
Power Control Register
7
6
5
-
4
3
2
1
0
SMOD1
SMOD0
POF
GF1
GF0
PD
IDL
Bit
Bit
Number
Mnemonic Description
Serial port Mode bit 1
Set to select double baud rate in mode 1, 2 or 3.
7
6
5
SMOD1
Serial port Mode bit 0
SMOD0 Clear to select SM0 bit in SCON register.
Set to select FE bit in SCON register.
Reserved
-
The value read from this bit is indeterminate. Do not set this bit.
Power-off Flag
Clear to recognize next reset type.
Set by hardware when VCC rises from 0 to its nominal voltage. Can also be set by
software.
4
POF
General purpose Flag
3
2
1
0
GF1
GF0
PD
Cleared by user for general purpose usage.
Set by user for general purpose usage.
General purpose Flag
Cleared by user for general purpose usage.
Set by user for general purpose usage.
Power-down Mode bit
Cleared by hardware when reset occurs.
Set to enter power-down mode.
Idle Mode bit
Clear by hardware when interrupt or reset occurs.
Set to enter idle mode.
IDL
Reset Value = 00X1 0000b
Not bit addressable
54
AT89C5115
4128F–8051–05/06