PIC18F25K80 MICROCHIP [Microchip Technology], PIC18F25K80 Datasheet - Page 51

• Manufacturer Part Number: PIC18F25K80
• Manufacturer: MICROCHIP [Microchip Technology]

In planning the application’s routing and I/O assign-
ments, ensure that adjacent port pins and other signals
in close proximity to the oscillator are benign (i.e., free
of high frequencies, short rise and fall times, and other
similar noise).
For additional information and design guidance on
oscillator circuits, please refer to these Microchip
Application Notes, available at the corporate web site
(www.microchip.com):
• AN826, “Crystal Oscillator Basics and Crystal
• AN849, “Basic PICmicro
• AN943, “Practical PICmicro
• AN949, “Making Your Oscillator Work”
2.7
Unused I/O pins should be configured as outputs and
driven to a logic low state. Alternatively, connect a 1 kΩ
to 10 kΩ resistor to V
output to logic low.
 2011 Microchip Technology Inc.
Selection for rfPIC™ and PICmicro
and Design”
Unused I/Os
SS
on unused pins and drive the
®
Oscillator Design”
®
Oscillator Analysis
®
Devices”
Preliminary
PIC18F66K80 FAMILY
FIGURE 2-4:
(tied to ground)
Timer1 Oscillator
Bottom Layer
Copper Pour
Oscillator
GND
Primary
Crystal
OSCO
OSCI
C1
C2
T1 Oscillator: C1
DEVICE PINS
Single-Sided and In-Line Layouts:
Fine-Pitch (Dual-Sided) Layouts:
(tied to ground)
Copper Pour
SUGGESTED PLACEMENT
OF THE OSCILLATOR
CIRCUIT
Top Layer Copper Pour
`
`
(tied to ground)
`
Primary Oscillator
T1 Oscillator: C2
Crystal
DEVICE PINS
DS39977C-page 51
C2
C1
Oscillator
Crystal
OSC1
OSC2
GND
T1OSO
T1OS I