LM3S9781 Datasheet, PDF (60/1155 Pages) Texas Instruments – Stellaris® LM3S9781 Microcontroller

Architectural Overview
1.1.6
1.1.6.1
■ 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
■ 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 be configured
with an 18-mA pad drive for high-current applications
– Slew rate control for the 8-mA drive
– Open drain enables
– Digital input enables
Analog
The LM3S9781 controller provides analog functions integrated into the device, including:
■ Two 10-bit Analog-to-Digital Converters (ADC) with 16 analog input channels and 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 496)
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 10-bit conversion resolution and supports
16 input channels plus an internal temperature sensor. Four buffered sample sequencers allow
rapid sampling of up to eight analog input sources without controller intervention. Each sample
sequencer provides flexible programming with fully configurable input source, trigger events, interrupt
generation, and sequencer priority. A digital comparator function is included that allows the conversion
value to be diverted to a comparison unit that provides 16 digital comparators.
The LM3S9781 microcontroller provides two ADC modules with the following features:
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June 29, 2010
Texas Instruments-Advance Information