LM3S2139 Luminary Micro, Inc, LM3S2139 Datasheet - Page 31

• Manufacturer Part Number: LM3S2139
• Description: Lm3s2139 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

1.4.3
1.4.3.1
1.4.3.2
1.4.4
July 25, 2008
On the LM3S2139, PWM motion control functionality can be achieved through:
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CCP Pins (see page 188)
The General-Purpose Timer Module's CCP (Capture Compare PWM) pins are software programmable
to support a simple PWM mode with a software-programmable output inversion of the PWM signal.
Analog Peripherals
To handle analog signals, the LM3S2139 microcontroller offers an Analog-to-Digital Converter
(ADC).
For support of analog signals, the LM3S2139 microcontroller offers three analog comparators.
ADC (see page 241)
An analog-to-digital converter (ADC) is a peripheral that converts a continuous analog voltage to a
discrete digital number.
The LM3S2139 ADC module features 10-bit conversion resolution and supports four input channels,
plus an internal temperature sensor. Four buffered sample sequences allow rapid sampling of up
to eight analog input sources without controller intervention. Each sample sequence provides flexible
programming with fully configurable input source, trigger events, interrupt generation, and sequence
priority.
Analog Comparators (see page 428)
An analog comparator is a peripheral that compares two analog voltages, and provides a logical
output that signals the comparison result.
The LM3S2139 microcontroller provides three independent integrated analog comparators that can
be configured to drive an output or generate an interrupt or ADC event.
A comparator can compare a test voltage against any one of these voltages:
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The comparator can provide its output to a device pin, acting as a replacement for an analog
comparator on the board, or it can be used to signal the application via interrupts or triggers to the
ADC to cause it to start capturing a sample sequence. The interrupt generation and ADC triggering
logic is separate. This means, for example, that an interrupt can be generated on a rising edge and
the ADC triggered on a falling edge.
Serial Communications Peripherals
The LM3S2139 controller supports both asynchronous and synchronous serial communications
with:
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The motion control features of the general-purpose timers using the CCP pins
An individual external reference voltage
A shared single external reference voltage
A shared internal reference voltage
Two fully programmable 16C550-type UARTs
One SSI module
One I
2
C module
Preliminary
LM3S2139 Microcontroller
31