LM3S102-IRN20 Luminary Micro, Inc., LM3S102-IRN20 Datasheet - Page 297

• Manufacturer Part Number: LM3S102-IRN20
• Description: Microcontroller
• Manufacturer: Luminary Micro, Inc.

14.2.1
October 6, 2006
Figure 14-2. Structure of Comparator Unit
A comparator is configured through two status/control registers (ACCTL and ACSTAT). The
internal reference is configured through one control register (ACREFCTL). Interrupt status and
control is configured through three registers (ACMIS, ACRIS, and ACINTEN). The operating
modes of the comparators are shown in Table 14-1.
Typically, the comparator output is used internally to generate controller interrupts. It may also be
used to drive an external pin.
Important:
Table 14-1. Comparator 0 Operating Modes
Internal Reference Programming
The structure of the internal reference is shown in Figure 14-3. This is controlled by a single
configuration register (ACREFCTL). Table 14-2 shows the programming options to develop
specific internal reference values, to compare an external voltage against a particular voltage
generated internally.
00
01
10
11
ACCNTL0
ASRCP
Certain register bit values must be set before using the analog comparators. The
proper pad configuration for the comparator input and output pins are described in
Table 8-1 on page 104.
+ve input (alternate)
reference input
VIN-
C0-
C0-
C0-
C0-
+ve input
-ve input
Preliminary
0
1
2
ACCTL
reserved
VIN+
C0+
C0+
Vref
Comparator 0
CINV
ACSTAT
Output
IntGen
C0o
C0o
C0o
C0o
output
LM3S102 Data Sheet
Interrupt
yes
yes
yes
yes
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