LM3S1138 Luminary Micro, Inc, LM3S1138 Datasheet - Page 413

• Manufacturer Part Number: LM3S1138
• Description: Lm3s1138 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

July 26, 2008
Figure 16-2. Structure of Comparator Unit
+ve input (alternate)
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 the Comparator Operating Mode tables.
Typically, the comparator output is used internally to generate controller interrupts. It may also be
used to drive an external pin or generate an analog-to-digital converter (ADC) trigger.
Important:
Table 16-1. Comparator 0 Operating Modes
Table 16-2. Comparator 1 Operating Modes
a. C1o and C1+ signals share a single pin and may only be used as one or the other.
ACCNTL0
ASRCP
00
01
10
11
ACCNTL1
ASRCP
00
01
10
11
reference input
+ve input
Comparator 0
VIN-
Comparator 1
VIN-
C0-
C0-
C0-
C0-
C1-
C1-
C1-
C1-
-ve input
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 the
Comparator Operating Mode tables.
VIN+
reserved
VIN+
C1o/C1+
reserved
C0+
C0+
Vref
C0+
Vref
a
Output
0
1
2
Output
C1o/C1+
C1o/C1+
C1o/C1+
C1o/C1+
C0o
C0o
C0o
C0o
ACCTL
Interrupt
Interrupt
yes
yes
yes
yes
yes
yes
yes
yes
Preliminary
ADC Trigger
ADC Trigger
yes
yes
yes
yes
yes
yes
yes
yes
CINV
ACSTAT
TrigGen
IntGen
LM3S1138 Microcontroller
output
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