dsPIC33FJ32MC204 Microchip Technology, dsPIC33FJ32MC204 Datasheet - Page 171

• Manufacturer Part Number: dsPIC33FJ32MC204
• Description: (dsPIC33FJ16MC304 / dsPIC33FJ32MC20x) 16-bit Microcontrollers
• Manufacturer: Microchip Technology

15.0
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 15-1:
© 2007 Microchip Technology Inc.
Note:
UPDN
INDX
QEA
QEB
QUADRATURE ENCODER
INTERFACE (QEI) MODULE
This data sheet summarizes the features
of
dsPIC33FJ16MC304 devices. It is not
intended to be a comprehensive reference
source. To complement the information in
this data sheet, refer to the “dsPIC33F
Family Reference Manual”. Please see
the Microchip web site (www.micro-
chip.com) for the latest dsPIC33F Family
Reference Manual sections.
Synchronize
Sleep Input
the
Det
PCDOUT
UPDN_SRC
dsPIC33FJ32MC202/204
QUADRATURE ENCODER INTERFACE BLOCK DIAGRAM
Programmable
Programmable
0
1
Programmable
1
0
Digital Filter
Digital Filter
Digital Filter
QEICON<11>
Existing Pin Logic
Up/Down
3
QEIM<2:0>
T
CY
Interface Logic
Quadrature
TQCS
Encoder
1
0
Mode Select
QEIM<2:0>
and
Preliminary
3
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 (QEICON<10:8>).
Figure 15-1 depicts the Quadrature Encoder Interface
block diagram.
index pulse
16-bit Up/Down Counter
Max Count Register
D
CK
Comparator/
Zero Detect
(POSCNT)
(MAXCNT)
TQCKPS<1:0>
Q
Q
1, 8, 64, 256
Prescaler
2
Reset
Equal
DS70283B-page 169
QEIIF
Event
Flag