PIC24EP256GU810-I Datasheet, PDF (217/622 Pages) Electronic Film Capacitors, Inc. – 16-Bit Microcontrollers and Digital Signal Controllers with High-Speed PWM, USB and Advanced Analog

dsPIC33EPXXX(GP/MC/MU)806/810/814 and PIC24EPXXX(GP/GU)810/814
11.4.4.2 Virtual Connections
The dsPIC33EPXXX(GP/MC/MU)806/810/814 and
PIC24EPXXX(GP/GU)810/814 devices support virtual
(internal) connections to the output of the comparator
modules, CMP1OUT, CMP2OUT and CMP3OUT (see
Figure 25-1 in Section 25.0 “Comparator Module”).
In addition, dsPIC33EPXXXMU806/810/814 devices
support virtual connections to the filtered QEI module
inputs, FINDX1, FHOME1, FINDX2 and FHOME2 (see
Figure 17-1 in Section 17.0 “Quadrature Encoder
Interface (QEI) Module (dsPIC33EPXXX(MC/
MU)8XX Devices Only)”.
Virtual connections provide a simple way of inter-
peripheral connection without utilizing a physical pin.
For example, by setting the FLT1R<6:0> bits of the
RPINR12 register to the value of ‘b0000001, the
output of the analog comparator, CMP1OUT, will be
connected to the PWM Fault 1 input, which allows the
analog comparator to trigger PWM Faults without the
use of an actual physical pin on the device.
Virtual connection to the QEI module allows
peripherals to be connected to the QEI digital filter
input. To utilize this filter, the QEI module must be
enabled, and its inputs must be connected to a physical
RPn/RPIn pin. Example 11-2 illustrates how the input
capture module can be connected to the QEI digital
filter.
11.4.4.3 Mapping Limitations
The control schema of the peripheral select pins is not
limited to a small range of fixed peripheral
configurations. There are no mutual or hardware
enforced lockouts between any of the peripheral
mapping SFRs. Literally any combination of peripheral
mappings across any or all of the RPn/RPIn pins is
possible. This includes both many-to-one and one-to-
many mappings of peripheral inputs and outputs to
pins. While such mappings may be technically possible
from a configuration point of view, they may not be
supportable from an electrical point of view.
EXAMPLE 11-2: CONNECTING IC1 TO HOME1 DIGITAL FILTER INPUT ON PIN 3 OF THE
dsPIC33EP512MU810 DEVICE
RPINR15 = 0x5600;
RPINR7 = 0x009;
/* Connect the QEI1 HOME1 input to RP86 (pin 3) */
/* Connect the IC1 input to the digital filter on the FHOME1 input */
QEI1IOC = 0x4000;
QEI1CON = 0x8000;
/* Enable the QEI digital filter */
/* Enable the QEI module */
 2009-2012 Microchip Technology Inc.
DS70616G-page 217