LM3S2918 Luminary Micro, Inc, LM3S2918 Datasheet - Page 453

• Manufacturer Part Number: LM3S2918
• Description: Lm3s2918 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

17
17.1
July 26, 2008
Analog Comparators
An analog comparator is a peripheral that compares two analog voltages, and provides a logical
output that signals the comparison result.
The LM3S2918 controller provides two independent integrated analog comparators 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 17-1. Analog Comparator Module Block Diagram
internal
C0+
C1-
C1+
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 454 for more information.
ACREFCTL
Voltage
Ref
-ve input
+ve input
+ve input (alternate)
reference input
-ve input
+ve input
+ve input (alternate)
reference input
ACSTAT1
ACSTAT0
ACCTL1
ACCTL0
Comparator 1
Comparator 0
interrupt
interrupt
trigger
trigger
output
output
C1o
trigger
C0o
trigger
Interrupt Control
Preliminary
ACINTEN
interrupt
ACMIS
ACRIS
LM3S2918 Microcontroller
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