Microchip Technology dsPIC30F - I;O Pin Control

dsPIC30F Family Reference Manual
DS70063C-page 16-18 © 2004 Microchip Technology Inc.
16.8 I/O Pin Control
Enabling the QEI module causes the associated I/O pins to come under the control of the QEI
and prevents lower priority I/O functions such as Ports from affecting the I/O pin.
Depending on the mode specified by QEIM<2:0> and other control bits, the I/O pins may
assume differing functions, as shown in Table 16-2 and Table 16-3.
Table 16-2: Quadrature Encoder Module Pinout I/O Descriptions
Table 16-3: Module I/O Mode Functions
Pin Name Pin Type Buffer Type Description
QEA I
I
I
ST
ST
ST
Quadrature Encoder Phase A Input, or
Auxiliary Timer External Clock Input, or
Auxiliary Timer External gate Input
QEB I
I
ST
ST
Quadrature Encoder Phase B Input, or
Auxiliary Timer Up/Down select input
INDX I ST Quadrature Encoder Index Pulse Input
UPDN O Position Up/Down Counter Direction Status,
QEI mode
Legend: I = Input, O = Output, ST = Schmitt Trigger
QEIM<2:0>
PCDOUT
UDSRC
TQGATE
TQCS
QEA
pin
QEB
pin
INDX
pin
UPDN
pin
000,010,011
Module Off
N/A N/A N/A N/A
001
Timer Mode
N/A 000
100 Input
(UPDN)
010Input (TQGATE)
Port not disabled
110Input (TQGATE)
Port not disabled
Input
(UPDN)
0 N/A 1 Input (TQCKI)
Port not disabled
1 N/A 1 Input (TQCKI)
Port not disabled
Input
(UPDN)
101,111
QEI
Reset by count
0 N/A N/A N/A Input (QEA) Input
(QEB)
1 N/A N/A N/A Input (QEA) Input
(QEB)
Output
(UPDN)
100,110
QEI
Reset by Index
0 N/A N/A N/A Input (QEA) Input
(QEB)
Input
(INDX)
1 N/A N/A N/A Input (QEA) Input
(QEB)
Input
(INDX)
Output
(UPDN)
Note: Empty slot indicates pin not used by QEI in this configuration,pin controlled by I/O port
logic.