Getting started with the PIC18-Q20 family of 8-bit microcontrollers requires attention to a minimal set of device pin connections before proceeding with development.
The following pins must always be connected:
- All VDD and VSS pins (see the Power Supply Pins section)
- MCLR pin (see the MCLRMaster Clear () Pin section)
These pins must also be connected if they are being used in the end application:
- ICSPCLK/ICSPDAT pins used for In-Circuit Serial Programming™ (ICSP™) and debugging purposes (see the In-Circuit Serial Programming (ICSP) Pins section)
- OSCI and OSCO pins when an external oscillator source is used (see the External Oscillator Pins section)
Additionally, the following pins may be required:
- VREF+/VREF- pins are used when external voltage reference for analog modules is implemented
The minimum mandatory connections are shown in the figure below.
Figure 1. Recommended Minimum
Connections
