Eurotech Appliances CPU-1461 - Manual (Page 16)

16 PC/104-Plus – CPU-1461 Module
ƒ System reset
The connection of the multifunction connector pin 9 to ground performs a hardware reset of the
module. It is possible to use an external push-button (normally open) to manually reset the system.
The reset signal is “de-bounced” on the board.
ƒ External Battery
Pin 7 of the multifunction connector allows the connection of an external backup battery.
If you connect a battery, then the voltage must be between 3.0V and 3.9V.
This battery is used when the system is powered down to preserve the Real Time Clock data.
The typical battery consumption with the module off is 7uA.
ƒ Speaker
A transistor that supplies 0.1W to an external speaker controls these outputs. A transistor amplifier
buffers the speaker signal. Use a small general-purpose 2” or 3” permanent magnet speaker with an
8
Ω voice coil. The audio output is based on two signals: one come from the output of Timer 2, and
the other come from I/O port 61h compliant with the AT Standard.
The Eurotech Multifunction Adapter
The Eurotech Multifunction Adapter simplifies the connection of mouse and keyboard with two PS/2
connectors, a speaker, battery and a reset pushbutton.
Mouse Keyboard
Reset
Pushbutton
Power Led
Spkr Led
Speaker
To Multif. Conn.
Of CPU Board
(Mouse sign.)
Not
used
Battery
To Multif. Conn.
of CPU Board
J4
J5 J6
J3 J2 S1
J1
Figure 5. Multifunction Adapter (both sides)