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Bit Addressable SFRs (alphabetical)
F-5
Bit-Addressable SFRs (alphabetical)
Port 1 (P1)
SFR Name: P1
SFR Address: 90
H
Bit−Addressable: Yes
Bit−Definitions:
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
Name P1.7 P1.6 P1.5 P1.4 P1.3 P1.2 T2EX T2
Bit Address 97
H
96
H
95
H
94
H
93
H
92
H
91
H
90
H
T2EX—Timer 2 Capture/Reload. Optional external capturing or reloading of
timer 2.
T2—Timer 2 External Input. Optionally used to control timer/counter 2 via
external source.
Port 2 (P2)
SFR Name: P2
SFR Address: A0
H
Bit−Addressable: Yes
Bit−Definitions:
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
Name A15 A14 A13 A12 A11 A10 A9 A8
Bit Address A7
H
A6
H
A5
H
A4
H
A3
H
A2
H
A1
H
A0
H
Note:
These bit names indicate the function of that I/O line on the P2 bus when
used with external memory (code/RAM). A standard 8052 assembler will not
recognize these bits by the given names; they will only be recognized as
P2.7, P2.6, etc.
Note:
Port 2 is only available for general input/output if the project does not use ex-
ternal code memory or external RAM. When such external memory is used,
Port 2 is used automatically by the microcontroller to address the memory
and read/write data from/to said memory.