DSPIC33FJ64MC508 Microchip Technology Inc., DSPIC33FJ64MC508 Datasheet - Page 190

• Manufacturer Part Number: DSPIC33FJ64MC508
• Description: High-performance, 16-bit Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

dsPIC33FJXXXMCX06/X08/X10 MOTOR CONTROL FAMILY
16.7.2
When the CPU is placed in the Idle mode and the QEI
module is configured in the 16-bit Timer mode, the
16-bit timer will operate if QEISIDL (QEICON<13>) = 0.
This bit defaults to a logic ‘0’ upon executing POR. To
halt the timer module during the CPU Idle mode,
QEISIDL should be set to ‘1’.
If the QEISIDL bit is cleared, the timer will function
normally – as if the CPU Idle mode had not been
entered.
16.8
The Quadrature Encoder Interface has the ability to
generate an interrupt on the occurrence of the following
events:
• Interrupt on 16-bit up/down position counter
• Detection of qualified index pulse or if CNTERR
• Timer period match event (overflow/underflow)
• Gate accumulation event
The QEI Interrupt Flag bit, QEIIF, is asserted upon
occurrence of any of the above events. The QEIIF bit
must be cleared in software. QEIIF is located in the
IFS3 register.
Enabling an interrupt is accomplished via the respec-
tive enable bit, QEIIE. The QEIIE bit is located in the
IEC3 register.
DS70287A-page 188
rollover/underflow
bit is set
Quadrature Encoder Interface
Interrupts
TIMER OPERATION DURING CPU
IDLE MODE
16.9
The QEI module has four user-accessible registers.
The registers are accessible in either Byte or Word
mode. These registers are as follows:
• Control/Status Register (QEICON) – This register
• Digital Filter Control Register (DFLTCON) – This
• Position Count Register (POSCNT) – This regis-
• Maximum Count Register (MAXCNT) – The
allows control of the QEI operation and status
flags indicating the module’s state.
register allows control of the digital input filter
operation.
ter allows reading and writing of the 16-bit position
counter.
MAXCNT register holds a value that is compared
to the POSCNT counter in some operations.
Note:
Control and Status Registers
The
accesses; however, reading the register in
byte mode may result in partially updated
values in subsequent reads. Either use
Word mode reads/writes or ensure that
the counter is not counting during byte
operations.
POSCNT
© 2007 Microchip Technology Inc.
register
allows
byte