LM3S1811 Datasheet, PDF (819/946 Pages) Texas Instruments – Stellaris® LM3S1811 Microcontroller

Stellaris^® LM3S1811 Microcontroller
5. Configure the internal voltage reference to 1.65 V by writing the ACREFCTL register with the
value 0x0000.030C.
6. Configure the comparator to use the internal voltage reference and to not invert the output by
writing the ACCTLn register with the value of 0x0000.040C.
7. Delay for 10 µs.
8. Read the comparator output value by reading the ACSTATn register’s OVAL value.
Change the level of the comparator negative input signal C- to see the OVAL value change.
17.5
Register Map
Table 17-4 on page 819 lists the comparator registers. The offset listed is a hexadecimal increment
to the register’s address, relative to the Analog Comparator base address of 0x4003.C000. Note
that the analog comparator clock must be enabled before the registers can be programmed (see
page 252). There must be a delay of 3 system clocks after the analog comparator module clock is
enabled before any analog comparator module registers are accessed.
Table 17-4. Analog Comparators Register Map
Offset Name
Type
Reset
Description
0x000
0x004
0x008
0x010
0x020
0x024
0x040
0x044
ACMIS
ACRIS
ACINTEN
ACREFCTL
ACSTAT0
ACCTL0
ACSTAT1
ACCTL1
R/W1C
RO
R/W
R/W
RO
R/W
RO
R/W
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
Analog Comparator Masked Interrupt Status
Analog Comparator Raw Interrupt Status
Analog Comparator Interrupt Enable
Analog Comparator Reference Voltage Control
Analog Comparator Status 0
Analog Comparator Control 0
Analog Comparator Status 1
Analog Comparator Control 1
See
page
820
821
822
823
824
825
824
825
17.6
Register Descriptions
The remainder of this section lists and describes the Analog Comparator registers, in numerical
order by address offset.
January 21, 2012
819
Texas Instruments-Production Data