LM3S3748 Datasheet, PDF (591/753 Pages) List of Unclassifed Manufacturers – Microcontroller

LM3S3748 Microcontroller
18
18.1
Analog Comparators
An analog comparator is a peripheral that compares two analog voltages, and provides a logical
output that signals the comparison result.
The LM3S3748 controller provides two independent integrated analog comparators that can be
configured to drive an output or generate an interrupt or ADC event.
Note: Not all comparators have the option to drive an output pin. See the Comparator Operating
Mode tables in “Functional Description” on page 592 for more information.
A comparator can compare a test voltage against any one of these voltages:
■ An individual external reference voltage
■ A shared single external reference voltage
■ A shared internal reference voltage
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 18-1. Analog Comparator Module Block Diagram
C1-
-ve input _{Comparator 1}
C1+
+ve input
output
<none>
+ve input (alternate)
ACCTL1
trigger
trigger
ACSTAT1
interrupt
reference input
C0-
-ve input _{Comparator 0}
C0+
+ve input
output
C0o
+ve input (alternate)
ACCTL0
trigger
ACSTAT0
interrupt
reference input
trigger
internal
bus
Voltage
Ref
ACREFCTL
Interrupt Control
ACRIS
ACMIS
ACINTEN
interrupt
April 08, 2008
591
Preliminary