LM3S6753 Datasheet, PDF (534/625 Pages) Texas Instruments – Stellaris LM3S6753 Microcontroller

Quadrature Encoder Interface (QEI)
■ Write the QEICTL register with the value of 0x0000.0018.
■ Write the QEIMAXPOS register with the value of 0x0000.0F9F.
5. Enable the quadrature encoder by setting bit 0 of the QEICTL register.
6. Delay for some time.
7. Read the encoder position by reading the QEIPOS register value.
19.4
Register Map
Table 19-1 on page 534 lists the QEI registers. The offset listed is a hexadecimal increment to the
register’s address, relative to the module’s base address:
■ QEI0: 0x4002.C000
Table 19-1. QEI Register Map
Offset Name
Type
0x000 QEICTL
0x004 QEISTAT
0x008 QEIPOS
0x00C QEIMAXPOS
0x010 QEILOAD
0x014 QEITIME
0x018 QEICOUNT
0x01C QEISPEED
0x020 QEIINTEN
0x024 QEIRIS
0x028 QEIISC
R/W
RO
R/W
R/W
R/W
RO
RO
RO
R/W
RO
R/W1C
Reset
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
Description
QEI Control
QEI Status
QEI Position
QEI Maximum Position
QEI Timer Load
QEI Timer
QEI Velocity Counter
QEI Velocity
QEI Interrupt Enable
QEI Raw Interrupt Status
QEI Interrupt Status and Clear
See
page
535
537
538
539
540
541
542
543
544
545
546
19.5
Register Descriptions
The remainder of this section lists and describes the QEI registers, in numerical order by address
offset.
534
April 05, 2010
Texas Instruments-Production Data