Introduction
1192
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
General-Purpose Input/Outputs (GPIOs)
17.1 Introduction
The GPIO module has the following features:
•
Up to 140 GPIOs, depending on configuration
•
Highly flexible pin muxing allows use as GPIO or one of several peripheral functions
•
3.3 -V-tolerant in input configuration
•
Advanced High Performance Bus accesses all ports:
–
Ports A to H and J; Ports K to N and P to T
•
Fast toggle capable of a change every clock cycle for ports on AHB
•
Programmable control for GPIO interrupts
–
Interrupt generation masking
–
Edge-triggered on rising, falling, or both
–
Level-sensitive on High or Low values
–
Per-pin interrupts available on Port P and Port Q
•
Bit masking in both read and write operations through address lines
•
Can be used to initiate an ADC sample sequence or a
μ
DMA transfer
•
Pin state can be retained during Hibernation mode ; pins on port P can be programmed to wake on
level in Hibernation mode
•
Pins configured as digital inputs are Schmitt-triggered
•
Programmable control for GPIO pad configuration
–
Weak pullup or pulldown resistors
–
2-mA, 4-mA, 6-mA, 8-mA, 10-mA and 12-mA pad drive for digital communication; up to four pads
can sink 18-mA for high-current applications
–
Slew rate control for 8-mA, 10-mA and 12-mA pad drive
–
Open drain enables
–
Digital input enables
17.2 Pad Capabilities
There are two main types of pads provided on the device:
•
Fast GPIO pads: These pads provide variable, programmable drive strength and optimized voltage
output levels.
•
Slow GPIO pads: These pads provide 2-mA drive strength and are designed to be sensitive to voltage
inputs. The following GPIOs port pins are designed with Slow GPIO Pads:
–
PJ1
See the
Specifications
chapter of the device-specific data sheet for details on the GPIO operating
conditions for these two different pad types.
NOTE:
Port pins PL6 and PL7 operate as Fast GPIO pads, but have 4-mA drive capability only.
GPIO register controls for drive strength, slew rate and open drain have no effect on these
pins. The registers which have no effect are as follows: GPIODR2R, GPIODR4R,
GPIODR8R, GPIODR12R, GPIOSLR, and GPIOODR .
NOTE:
Port pins PM[7:4] operate as Fast GPIO pads but support only 2-, 4-, 6-, and 8-mA drive
capability. 10- and 12-mA drive are not supported. All standard GPIO register controls,
except for the GPIODR12R register, apply to these port pins.