LM3S5D56 Datasheet, PDF (941/1146 Pages) Texas Instruments – Stellaris® LM3S5D56 Microcontroller

Stellaris^® LM3S5D56 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.
Note: Not all comparators have the option to drive an output pin. See “Signal
Description” on page 942 for more information.
The comparator can provide its output to a device pin, acting as a replacement for an analog
comparator on the board. In addition, the comparator can signal the application via interrupts or
trigger the start of a sample sequence in the ADC. The interrupt generation and ADC triggering logic
is separate and independent. This flexibility means, for example, that an interrupt can be generated
on a rising edge and the ADC triggered on a falling edge.
The Stellaris^® LM3S5D56 microcontroller provides two independent integrated analog comparators
with the following functions:
■ Compare external pin input to external pin input or to internal programmable voltage reference
■ Compare a test voltage against any one of the following voltages:
– An individual external reference voltage
– A shared single external reference voltage
– A shared internal reference voltage
Block Diagram
Figure 18-1. Analog Comparator Module Block Diagram
C1-
-ve input _{Comparator 1}
C1+
+ve input
output
C1o
+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
trigger
ACSTAT0
interrupt
reference input
internal
bus
Voltage
Ref
ACREFCTL
Interrupt Control
ACRIS
ACMIS
ACINTEN
interrupt
January 23, 2012
941
Texas Instruments-Production Data