Chapter 7
SWRU191C
–
April 2009
–
Revised January 2012
I/O Ports
There are 21 digital input/output pins that can be configured as general-purpose digital I/O or as peripheral
I/O signals connected to the ADC, timers, or USART peripherals. The use of the I/O ports is fully
configurable from user software through a set of configuration registers.
The I/O ports have the following key features:
•
21 digital input/output pins
•
General-purpose I/O or peripheral I/O
•
Pullup or pulldown capability on inputs
•
External interrupt capability
The external interrupt capability is available on all 21 I/O pins. Thus, external devices may generate
interrupts if required. The external interrupt feature can also be used to wake the device up from sleep
mode (power modes PM1/PM2/PM3).
Topic
...........................................................................................................................
Page
7.1
Unused I/O Pins
................................................................................................
7.2
Low I/O Supply Voltage
......................................................................................
7.3
General-Purpose I/O
..........................................................................................
7.4
General-Purpose I/O Interrupts
...........................................................................
7.5
General-Purpose I/O DMA
...................................................................................
7.6
Peripheral I/O
....................................................................................................
7.7
Debug Interface
.................................................................................................
7.8
32-kHz XOSC Input
............................................................................................
7.9
Radio Test Output Signals
..................................................................................
7.10
Power-Down Signal MUX (PMUX)
........................................................................
7.11
I/O Registers
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81
SWRU191C
–
April 2009
–
Revised January 2012
I/O Ports
Copyright
©
2009
–
2012, Texas Instruments Incorporated