LM3S6C11 Datasheet, PDF (392/828 Pages) Texas Instruments – Stellaris® LM3S6C11 Microcontroller

OBSOLETE: TI has discontinued production of this device.
General-Purpose Input/Outputs (GPIOs)
9 General-Purpose Input/Outputs (GPIOs)
The GPIO module is composed of seven physical GPIO blocks, each corresponding to an individual
GPIO port (Port A, Port B, Port C, Port D, Port E, Port F, Port G). The GPIO module supports up to
46 programmable input/output pins, depending on the peripherals being used.
The GPIO module has the following features:
■ Up to 46 GPIOs, depending on configuration
■ Highly flexible pin muxing allows use as GPIO or one of several peripheral functions
■ 5-V-tolerant in input configuration
■ Two means of port access: either Advanced High-Performance Bus (AHB) with better back-to-back
access performance, or the legacy Advanced Peripheral Bus (APB) for backwards-compatibility
with existing code
■ Fast toggle capable of a change every clock cycle for ports on AHB, every two clock cycles for
ports on APB
■ Programmable control for GPIO interrupts
– Interrupt generation masking
– Edge-triggered on rising, falling, or both
– Level-sensitive on High or Low values
■ Bit masking in both read and write operations through address lines
■ Pins configured as digital inputs are Schmitt-triggered
■ Programmable control for GPIO pad configuration
– Weak pull-up or pull-down resistors
– 2-mA, 4-mA, and 8-mA pad drive for digital communication; up to four pads can sink 18-mA
for high-current applications
– Slew rate control for the 8-mA drive
– Open drain enables
– Digital input enables
9.1 Signal Description
GPIO signals have alternate hardware functions. The following table lists the GPIO pins and their
digital alternate functions. Other analog signals are 5-V tolerant and are connected directly to their
circuitry (C0-, C0+, C1-, C1+). These signals are configured by clearing the DEN bit in the GPIO
Digital Enable (GPIODEN) register. All GPIO signals are 5-V tolerant when configured as inputs
except for PB0 and PB1, which are limited to 3.6 V. The digital alternate hardware functions 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)
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July 24, 2012
Texas Instruments-Production Data