Utility Connector
26
– Reference
VSBC-8 Reference Manual
Utility Connector
K
EYBOARD
/M
OUSE
I
NTERFACE
A standard PS/2 keyboard and mouse interface is accessible through connector J13. In addition,
connector J13 supports a programmable LED output, hard drive activity LED, and a speaker
output as shown in the table below. The pinout of the PS/2 connectors applies to use of the
VersaLogic transition cable #VL-CBL-1602.
Table 9: Utility Connector
J13
Pin
Signal
Name
Description
PS/2
Pin
1
PBRST*
Push-button reset
2
GND
Ground
3
PLED*
Programmable LED
4
MKPWR
Pro5V
5
SPKO*
Speaker Output
6
MKPWR
Pro5V
7
IDE_LED*
IDE Drive Indicator LED
8
MKPWR
Pro5V
9
MKPWR
Pro5V
4
10
XMSDATA
Mouse Data
1
11
GND
Ground
3
12
MSCLK
Mouse Clock
5
13
MKPWR
Pro5V
4
14
KBDATA
Keyboard Data
1
15
GND
Ground
3
16
KBCLK
Keyboard Clock
5
P
ROGRAMMABLE
LED
The Utility Connector J13 includes an output signal for attaching a software controlled LED.
Connect the cathode of the LED to J13 pin 3, connect the anode to +5V. An on-board resistor
limits the current to 15 mA when the circuit is turned on.
To turn the LED on and off, set or clear bit D7 in I/O port 0E0h (or 1E0h). When changing the
register, make sure not to alter the value of the other bits.
The following code examples show how to turn on and off the LED. Refer to page 48 for further
information:
LED On
LED Off
in
al,E0h
in
al,E0h
or
al,80h
and
al,7Fh
out
E0h,al
out
E0,al
Note!
The LED is turned on by the BIOS during system startup. This causes the light to
function as a "power on" indicator if it is not otherwise controlled by user code.
Mouse
Connector
Keyboard
Connector
