dspic33fj128mc706at-i-pt Microchip Technology Inc., dspic33fj128mc706at-i-pt Datasheet - Page 193

• Manufacturer Part Number: dspic33fj128mc706at-i-pt
• Description: High-performance, 16-bit Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

17.0
This section describes the Quadrature Encoder Inter-
face (QEI) module and associated operational modes.
The QEI module provides the interface to incremental
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
the dsPIC33FJXXXMCX06A/X08A/X10A
family of devices. However, it is not
intended to be a comprehensive reference
source. To complement the information in
this data sheet, refer to Section 15.
“Quadrature Encoder Interface (QEI)”
(DS70208) in the “dsPIC33F Family
Reference Manual”, which is available
from
(www.microchip.com).
Synchronize
Sleep Input
Det
PCDOUT
the
UPDN_SRC
QUADRATURE ENCODER INTERFACE BLOCK DIAGRAM
Programmable
Programmable
0
1
Programmable
0
1
Digital Filter
Digital Filter
Digital Filter
dsPIC33FJXXXMCX06A/X08A/X10A
QEIxCON<11>
Existing Pin Logic
Up/Down
Microchip
3
QEIM<2:0>
T
CY
Interface Logic
web
Quadrature
TQCS
Encoder
1
0
Mode Select
QEIM<2:0>
site
Preliminary
3
TQGATE
1
0
2
The operational features of the QEI include the
following:
• 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
The QEI module’s operating mode is determined by set-
ting the appropriate bits, QEIM<2:0> (QEIxCON<10:8>).
Figure 17-1 depicts the Quadrature Encoder Interface
block diagram.
an index pulse
16-Bit Up/Down Counter
Max Count Register
D
CK
Comparator/
Zero Detect
(MAXCNT)
(POSCNT)
TQCKPS<1:0>
Q
Q
1, 8, 64, 256
Prescaler
2
Reset
Equal
DS70594A-page 191
QExIF
Event
Flag