N*R
N*R
0x0
0x1
0xE
0xF
Decoder
Internal
Reference
V
IREF
R
R
R
Copyright © 2017, Texas Instruments Incorporated
ACCTL
CINV
output
ACSTAT
1
0
2
reference input
+ve input (alternate)
+ve input
-ve input
b
u
s
TrigGen
IntGen
in
te
rn
a
l
tri
g
g
e
r
in
te
rru
p
t
+
-
Copyright © 2017, Texas Instruments Incorporated
Functional Description
831
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Analog Comparators
Figure 12-2. Structure of Comparator Unit
A comparator is configured through two status and control registers, Analog Comparator Control (ACCTL)
and Analog Comparator Status (ACSTAT). The internal reference is configured through one control
register, Analog Comparator Reference Voltage Control (ACREFCTL). Interrupt status and control are
configured through three registers, Analog Comparator Masked Interrupt Status (ACMIS), Analog
Comparator Raw Interrupt Status (ACRIS), and Analog Comparator Interrupt Enable (ACINTEN).
Typically, the comparator output is used internally to generate an interrupt as controlled by the ISEN bit in
the ACCTL register. The output may also be used to drive one of the external pins (Cno), or generate an
analog-to-digital converter (ADC) trigger.
NOTE:
The ASRCP bits in the ACCTL register must be set before using the analog comparators.
12.3.1 Internal Reference Programming
The structure of the internal reference is shown in
. The internal reference is controlled by a
single configuration register (ACREFCTL).
Figure 12-3. Comparator Internal Reference Structure
NOTE:
In the figure above, N × R represents a multiple of the R value that produces the results
specified in
.