LM3S818 Datasheet, PDF (504/572 Pages) Bookham, Inc. – Microcontroller

Quadrature Encoder Interface (QEI)
Bit/Field
5
4
3
2
1
0
Name
VelEn
ResMode
CapMode
SigMode
Swap
Enable
Type
R/W
R/W
R/W
R/W
R/W
R/W
Reset
0
0
0
0
0
0
Description
Capture Velocity
When set, enables capture of the velocity of the quadrature encoder.
Reset Mode
The Reset mode for the position counter. When 0, the position counter
is reset when it reaches the maximum; when 1, the position counter is
reset when the index pulse is captured.
Capture Mode
The Capture mode defines the phase edges that are counted in the
position. When 0, only the PhA edges are counted; when 1, the PhA
and PhB edges are counted, providing twice the positional resolution
but half the range.
Signal Mode
When 1, the PhA and PhB signals are clock and direction; when 0, they
are quadrature phase signals.
Swap Signals
Swaps the PhA and PhB signals.
Enable QEI
Enables the quadrature encoder module.
504
July 14, 2014
Texas Instruments-Production Data