LM3S3749 Datasheet, PDF (725/898 Pages) Texas Instruments – Stellaris® LM3S3749 Microcontroller

Stellaris® LM3S3749 Microcontroller
17.3.1
Table 17-3. Comparator 1 Operating Modes
ACCTL1
ASRCP
00
01
10
11
Comparator 1
VIN-
C1-
C1-
C1-
C1-
VIN+
C1+
C0+
Vref
reserved
Output
C1o
C1o
C1o
C1o
Interrupt
yes
yes
yes
yes
ADC Trigger
yes
yes
yes
yes
Internal Reference Programming
The structure of the internal reference is shown in Figure 17-3 on page 725. This is controlled by a
single configuration register (ACREFCTL). Table 17-4 on page 725 shows the programming options
to develop specific internal reference values, to compare an external voltage against a particular
voltage generated internally.
Figure 17-3. Comparator Internal Reference Structure
AVDD
8R
R
8R
R
R
•••
EN
VREF
RNG
15 14
•••
1
0
Decoder
internal
reference
Table 17-4. Internal Reference Voltage and ACREFCTL Field Values
ACREFCTL Register
EN Bit Value RNG Bit Value
EN=0
RNG=X
Output Reference Voltage Based on VREF Field Value
0 V (GND) for any value of VREF; however, it is recommended that RNG=1 and
VREF=0 for the least noisy ground reference.
November 17, 2011
725
Texas Instruments-Production Data