LM3S1637 Luminary Micro, Inc, LM3S1637 Datasheet - Page 413

• Manufacturer Part Number: LM3S1637
• Description: Lm3s1637 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

16
16.1
16.2
July 25, 2008
Analog Comparator
An analog comparator is a peripheral that compares two analog voltages, and provides a logical
output that signals the comparison result.
The LM3S1637 controller provides one analog comparator that can be configured to drive an output
or generate an interrupt or ADC event.
Note:
A comparator can compare a test voltage against any one of these voltages:
■
■
■
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.
Block Diagram
Figure 16-1. Analog Comparator Module Block Diagram
internal
Functional Description
Important:
The comparator compares the VIN- and VIN+ inputs to produce an output, VOUT.
VIN- < VIN+, VOUT = 1
VIN- > VIN+, VOUT = 0
C0+
C0-
bus
An individual external reference voltage
A shared single external reference voltage
A shared internal reference voltage
Not all comparators have the option to drive an output pin. See the Comparator Operating
Mode tables in “Functional Description” on page 413 for more information.
ACREFCTL
Voltage
It is recommended that the Digital-Input enable (the GPIODEN bit in the GPIO module)
for the analog input pin be disabled to prevent excessive current draw from the I/O
pads.
Ref
-ve input
+ve input
+ve input (alternate)
reference input
ACSTAT0
ACCTL0
Comparator 0
interrupt
trigger
output
Interrupt Control
Preliminary
C0o
trigger
ACINTEN
interrupt
ACMIS
ACRIS
LM3S1637 Microcontroller
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