LM3S9U90 Datasheet, PDF (63/1310 Pages) Texas Instruments – LM3S9U90

Stellaris^® LM3S9U90 Microcontroller
1.3.6
1.3.6.1
■ 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
■ Can be used to initiate an ADC sample sequence
■ 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
Analog
The LM3S9U90 microcontroller provides analog functions integrated into the device, including:
■ Two 12-bit Analog-to-Digital Converters (ADC) with 16 analog input channels and a sample rate
of one million samples/second
■ Three analog comparators
■ 16 digital comparators
■ On-chip voltage regulator
The following provides more detail on these analog functions.
ADC (see page 629)
An analog-to-digital converter (ADC) is a peripheral that converts a continuous analog voltage to a
discrete digital number. The Stellaris ADC module features 12-bit conversion resolution and supports
January 23, 2012
63
Texas Instruments-Production Data