LM3S6422 Datasheet, PDF (522/609 Pages) Texas Instruments – Stellaris® LM3S6422 Microcontroller

Analog Comparators
14.1
Block Diagram
Figure 14-1. 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
14.2
Signal Description
Table 14-1 on page 522 and Table 14-2 on page 523 list the external signals of the Analog Comparators
and describe the function of each. The Analog Comparator output signals are alternate functions
for some GPIO signals and default to be GPIO signals at reset. The column in the table below titled
"Pin Assignment" lists the possible GPIO pin placements for the Analog Comparator signals. The
AFSEL bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 272) should be set
to choose the Analog Comparator function. The positive and negative input signals are configured
by clearing the DEN bit in the GPIO Digital Enable (GPIODEN) register. For more information on
configuring GPIOs, see “General-Purpose Input/Outputs (GPIOs)” on page 251.
Table 14-1. Analog Comparators Signals (100LQFP)
Pin Name
Pin Number Pin Type Buffer Type^a Description
C0+
90
I
Analog Analog comparator 0 positive input.
C0-
92
I
Analog Analog comparator 0 negative input.
C0o
100
O
TTL
Analog comparator 0 output.
C1+
24
I
Analog Analog comparator 1 positive input.
C1-
91
I
Analog Analog comparator 1 negative input.
C1o
24
O
TTL
Analog comparator 1 output.
a. The TTL designation indicates the pin has TTL-compatible voltage levels.
522
June 18, 2012
Texas Instruments-Production Data