ADuC824 Evaluation Board Reference Guide
(2) Evaluation Board Features
Version 1.0
Analog Devices Inc., MicroConverter
Page 6 of 14
www.analog.com/microconverter
Alternatively, if a push button switch is not required, the RESET output of an active high power
on reset chip (e.g. ADM810) can be used to directly drive the RESET pin of the ADuC824.
Reset/
INT0
INT0
Push Buttons:
A
RESET push button
is provided to allow the user to manually reset the part. This button is at the input
to the ADM809 (Power on Reset chip) so a delay of 240ms approx will be required for the part to be
actually released from reset after the button is released.
An
INT0
INT0
push button
switch is provided to allow the user perform external interrupts easily. The
INT0
signal is Schmitt triggered (U6) to prevent noise on the rising edge of
INT0
to cause multiple interrupts
as it passes the trip point. This Schmitt trigger also inverts the signal.
Power Indicator/General Purpose LEDs:
A green power LED (D2) is used to indicate that a sufficient supply is available on the board. A red
general purpose LED (D1) is connected to P3.4 of the ADuC824. An inverter is connected between the
LED and the port pin so that the SETB instruction turns the LED on and the CLR instruction turns the
LED off.
