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I/O Registers
The selected 32-kHz clock source can be output on one of the P0 pins. The enable bit
CKOEN
enables the
output on P0, and the pin of P0 is selected using the
CKOPIN
(see the
PMUX
register description for
details). When
CKOEN
is set, all other configurations for the selected pin are overridden. The clock is
output in all power modes; however, in PM3 the clock stops (see PM3 in
Furthermore, the digital regulator status can be output on one of the P1 pins. When the
DREGSTA
bit is
set, the status of the digital regulator is output.
DREGSTAPIN
selects the P1 pin (see the
PMUX
register
description for details). When
DREGSTA
is set, all other configurations for the selected pin are overridden.
The selected pin outputs 1 when the 1.8-V on-chip digital regulator is powered up (chip has regulated
power). The selected pin outputs 0 when the 1.8-V on-chip digital regulator is powered down, i.e., in PM2
and PM3.
7.11 I/O Registers
The registers for the I/O ports are described in this section. The registers are:
•
P0
: Port 0
•
P1:
Port 1
•
P2
: Port 2
•
PERCFG
: Peripheral-control register
•
APCFG
: Analog peripheral I/O configuration
•
P0SEL:
Port 0 function-select register
•
P1SEL:
Port 1 function-select register
•
P2SEL:
Port 2 function-select register
•
P0DIR:
Port 0 direction register
•
P1DIR:
Port 1 direction register
•
P2DIR
: Port 2 direction register
•
P0INP:
Port 0 input-mode register
•
P1INP:
Port 1 input-mode register
•
P2INP
: Port 2 input-mode register
•
P0IFG:
Port 0 interrupt-status flag register
•
P1IFG:
Port 1 interrupt-status flag register
•
P2IFG:
Port 2 interrupt-status flag register
•
PICTL
: Interrupt edge register
•
P0IEN
: Port 0 interrupt-mask register
•
P1IEN
: Port 1 interrupt-mask register
•
P2IEN
: Port 2 interrupt-mask register
•
PMUX
: Power-down signal-mux register
•
OBSSEL0
: Observation output control register 0
•
OBSSEL1
: Observation output control register 1
•
OBSSEL2
: Observation output control register 2
•
OBSSEL3
: Observation output control register 3
•
OBSSEL4
: Observation output control register 4
•
OBSSEL5
: Observation output control register 5
P0 (0x80)
–
Port 0
Bit
Name
Reset
R/W
Description
7:0
P0[7:0]
0xFF
R/W
Port 0. General-purpose I/O port. Bit-addressable from SFR. This CPU-internal register is readable,
but not writable, from XDATA (0x7080).
87
SWRU191C
–
April 2009
–
Revised January 2012
I/O Ports
Copyright
©
2009
–
2012, Texas Instruments Incorporated