LM3S818 Luminary Micro, Inc, LM3S818 Datasheet - Page 348

• Manufacturer Part Number: LM3S818
• Description: Lm3s818 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Quadrature Encoder Interface (QEI)
348
Reset
Reset
Type
Type
Bit/Field
31:13
QEI Control (QEICTL)
Offset 0x000
8:6
12
10
11
9
5
RO
RO
31
15
0
0
reserved
Register 1: QEI Control (QEICTL), offset 0x000
This register contains the configuration of the QEI module. Separate enables are provided for the
quadrature encoder and the velocity capture blocks; the quadrature encoder must be enabled in
order to capture the velocity, but the velocity does not need to be captured in applications that do
not need it. The phase signal interpretation, phase swap, Position Update mode, Position Reset
mode, and velocity predivider are all set via this register.
RO
RO
30
14
0
0
STALLEN
reserved
VelDiv
Name
VelEn
INVB
INVA
INVI
RO
RO
29
13
0
0
STALLEN
R/W
RO
28
12
0
0
INVI
Type
R/W
R/W
R/W
R/W
R/W
R/W
R/W
RO
RO
27
11
0
0
INVB
R/W
RO
26
10
0
0
Reset
INVA
R/W
RO
25
0
9
0
0
0
0
0
0
0
0
Preliminary
R/W
RO
24
0
8
0
reserved
Description
Reserved bits return an indeterminate value, and should
never be changed.
When set, the QEI stalls when the microcontroller asserts
Halt.
When set , the input Index Pulse is inverted.
When set, the
When set, the
A predivider of the input quadrature pulses before being
applied to the QEICOUNT accumulator. This field can be
set to the following values:
When set, enables capture of the velocity of the quadrature
encoder.
Binary Value
VelDiv
R/W
RO
23
0
7
0
000
001
010
100
101
011
110
111
R/W
RO
22
0
6
0
PHA
PHB
VelEn
R/W
RO
21
0
5
0
Predivider
input is inverted.
input is inverted.
÷128
÷16
÷32
÷64
÷1
÷2
÷4
÷8
ResMode
R/W
RO
20
0
4
0
CapMode
R/W
RO
19
0
3
0
SigMode
R/W
RO
18
0
2
0
February 6, 2007
Swap
R/W
RO
17
0
1
0
Enable
R/W
RO
16
0
0
0