LM3S8933 Luminary Micro, Inc, LM3S8933 Datasheet - Page 504

• Manufacturer Part Number: LM3S8933
• Description: Lm3s8933 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Analog Comparators
504
Figure 18-2. 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 18-1. Comparator 0 Operating Modes
Table 18-2. Comparator 1 Operating Modes
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
Output
Output
C1o/C1+
C1o/C1+
C1o/C1+
C1o/C1+
0
1
2
C0o
C0o
C0o
C0o
ACCTL
Interrupt
Interrupt
yes
yes
yes
yes
yes
yes
yes
yes
Preliminary
ADCTrigger
ADCTrigger
yes
yes
yes
yes
yes
yes
yes
yes
CINV
ACSTAT
TrigGen
IntGen
output
July 25, 2008