The purpose of this application note is to design a clock
while multiplexing the features as much as possible,
allowing the circuit to use the 18-pin PIC16C54. Other
devices in the Microchip line expand on this part, mak-
ing it a good starting point for learning the basics. This
design is useful because it utilizes every pin for output
and switches some of them to inputs briefly to read the
keys. For a more extensive clock design, consult appli-
cation note AN529. AN590
A Clock Design Using the PIC16C54 for LED Displays and Switch Inputs
OPERATION
Author: Dan Matthews
Microchip Technology Inc. Switches
When no buttons are pressed, the circuit will display the
INTRODUCTION current time, starting at 12:00 on reset. Pressing SW1
The purpose of this application note is to design a clock will cause seconds to be displayed. The time is set by
while multiplexing the features as much as possible, pressing SW2 to advance minutes, and SW3 to
allowing……
