26
Signal Tables
The following tables list the signals available for each pin. Signals are configured as GPIOs on reset,
except for those noted below. Use the
GPIOAMSEL
register (see page 786) to select analog mode.
For a GPIO pin to be used for an alternate digital function, the corresponding bit in the
GPIOAFSEL
register (see page 770) must be set. Further pin muxing options are provided through the
PMCx
bit
field in the
GPIOPCTL
register (see page 787), which selects one of several available peripheral
functions for that GPIO.
Important:
Table 10-1 on page 743 shows special consideration GPIO pins. Most GPIO pins are
configured as GPIOs and tri-stated by default (
GPIOAFSEL
=0,
GPIODEN
=0,
GPIOPDR
=0,
GPIOPUR
=0, and
GPIOPCTL
=0). Special consideration pins may be
programed to a non-GPIO function or may have special commit controls out of reset.
In addition, a Power-On-Reset (
POR
) returns these GPIO to their original special
consideration state.
Table 26-1. GPIO Pins With Special Considerations
GPIOCR
GPIOPCTL
GPIOPUR
GPIOPDR
GPIODEN
GPIOAFSEL
Default Reset
State
GPIO Pins
0
0x1
1
0
1
1
JTAG/SWD
PC[3:0]
0
0x0
0
0
0
0
GPIO
a
PD[7]
0
0x0
0
0
0
0
GPIO
a
PE[7]
a. This pin is configured as a GPIO by default but is locked and can only be reprogrammed by unlocking the
pin in the
GPIOLOCK
register and uncommitting it by setting the
GPIOCR
register.
Table 26-2 on page 1773 shows the pin-to-signal-name mapping, including functional characteristics
of the signals. Each possible alternate analog and digital function is listed for each pin.
Table 26-3 on page 1785 lists the signals in alphabetical order by signal name. If it is possible for a
signal to be on multiple pins, each possible pin assignment is listed. The "Pin Mux" column indicates
the GPIO and the encoding needed in the
PMCx
bit field in the
GPIOPCTL
register.
Table 26-4 on page 1797 groups the signals by functionality, except for GPIOs. If it is possible for a
signal to be on multiple pins, each possible pin assignment is listed.
Table 26-5 on page 1808 lists the GPIO pins and their analog and digital alternate functions. The
AINx
analog signals go through an isolation circuit before reaching their circuitry. These signals are
configured by clearing the corresponding
DEN
bit in the
GPIO Digital Enable (GPIODEN)
register
and setting the corresponding
AMSEL
bit in the
GPIO Analog Mode Select (GPIOAMSEL)
register.
Other analog signals are 3.3-V tolerant and are connected directly to their circuitry (
C0-
,
C0+
,
C1
-,
C1+
,
C2-
,
C2+
,
USB0VBUS
,
USB0ID
). These signals are configured by clearing the
DEN
bit in the
GPIO Digital Enable (GPIODEN)
register. The digital signals are enabled by setting the appropriate
bit in the
GPIO Alternate Function Select (GPIOAFSEL)
and
GPIODEN
registers and configuring
the
PMCx
bit field in the
GPIO Port Control (GPIOPCTL)
register to the numeric enoding shown in
the table below. Table entries that are shaded gray are the default values for the corresponding
GPIO pin.
Table 26-6 on page 1811 lists the signals based on number of possible pin assignments. This table
can be used to plan how to configure the pins for a particular functionality. Application Note AN01274
Configuring Tiva™ C Series Microcontrollers with Pin Multiplexing provides an overview of the pin
muxing implementation, an explanation of how a system designer defines a pin configuration, and
examples of the pin configuration process.
June 18, 2014
1772
Texas Instruments-Production Data
Signal Tables