dspic33fj128mc204 Microchip Technology Inc., dspic33fj128mc204 Datasheet - Page 221

• Manufacturer Part Number: dspic33fj128mc204
• Description: High-performance, 16-bit Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

17.0
This chapter describes the Quadrature Encoder
Interface (QEI) module and associated operational
modes. The QEI module provides the interface to incre-
mental encoders for obtaining mechanical position data.
FIGURE 17-1:
© 2009 Microchip Technology Inc.
Note:
UPDNx
INDXx
QEAx
QEBx
QUADRATURE ENCODER
INTERFACE (QEI) MODULE
This data sheet summarizes the features
of
dsPIC33FJ64MCX02/X04,
dsPIC33FJ128MCX02/X04
devices. It is not intended to be a
comprehensive
complement the information in this data
sheet, refer to the “dsPIC33F Family
Reference
“Quadrature Encoder Interface (QEI)”
(DS70208), which is available from the
Microchip website (www.microchip.com).
Synchronize
Sleep Input
Det
the
PCDOUT
UPDN_SRC
QUADRATURE ENCODER INTERFACE BLOCK DIAGRAM (x = 1 OR 2)
Programmable
Programmable
0
1
Programmable
1
0
Digital Filter
Digital Filter
Digital Filter
QEIxCON<11>
Manual”,
Existing Pin Logic
Up/Down
dsPIC33FJ32MC302/304,
3
reference
QEIM<2:0>
T
CY
Section
Interface Logic
families
source.
Quadrature
TQCS
Encoder
1
0
Mode Select
QEIM<2:0>
and
15.
Preliminary
To
3
of
TQGATE
1
0
2
The operational features of the QEI include:
• Three input channels for two phase signals and
• 16-bit up/down position counter
• Count direction status
• Position Measurement (x2 and x4) mode
• Programmable digital noise filters on inputs
• Alternate 16-bit Timer/Counter mode
• Quadrature Encoder Interface interrupts
These operating modes are determined by setting the
appropriate bits, QEIM<2:0> in (QEIxCON<10:8>).
Figure 17-1 depicts the Quadrature Encoder Interface
block diagram.
index pulse
Note:
16-bit Up/Down Counter
Max Count Register
D
CK
Comparator/
(POSxCNT)
(MAXxCNT)
Zero Detect
An ‘x’ used in the names of pins, control/
status bits and registers denotes a
particular Quadrature Encoder Interface
(QEI) module number (x = 1 or 2).
TQCKPS<1:0>
Q
Q
1, 8, 64, 256
Prescaler
2
Reset
Equal
DS70291C-page 219
QExIF
Event
Flag