Table of Contents
Advertisement
Chapter 3
Speaker
The signal lines for a speaker port with 0.1-watt drive are provided through a Utility 1 interface (J15).
Table 3-16. Utility 1 Interface Pin/Signal Descriptions (J15)
Pin # Signal
1
-12V
2
GND
3
-5V
4
GND
5
PwrLED
6
NC
7
SPKR+
8
GND
9
RSTSW*
10
NC
11
KBDATA
12
KBCLK
13
GND
14
KBDPWR
15
BATV+
16
BATV-
Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.
Utility 2 Interface (J13)
The Utility 2 interface consists of a 24-pin connector used to interface various signals to the external
board with external connections, or directly to the respective connector such as, the mouse, USB, etc.
Table 3-18 gives the pin-outs and interface signals for the Utility 2 interface and it has 24 pins, 2 rows,
odd/even, (1, 2) with 0.100" pin spacing.
•
PS/2 Mouse signals
• Infrared (IrDA) signals
• SMBus signals
• USB signals for USB ports 1 and 2
• Power button signal
System Management Bus (SMBus)
The I/O Hub, 82801DBM, (Southbridge) contains both a host and slave SMBus port; but the host cannot
access the slave internally. The slave port allows an external master access to the I/O Hub through the
connector (J13). The master contained in the 82801DBM is used to communicate with the SDRAM
DDR DIMM, 82541(GI/PI) Gigabit Ethernet controller, and the clock generator. Table 3-17 gives the
addresses for these devices with the components and corresponding binary addresses of the SMBus.
46
I/O
Description
I
-12 Volts – Supplied from external power source.
I
Ground
I
-5 Volts – Supplied from external power source.
I
Ground
O
Power On LED – This on-board +3.3 volts is provided through 330 ohm
resistor to an external Power-On LED.
-
Not connected (Power Good)
O
+ Speaker Output – This signal drives external PC "Beep" speaker.
I
Ground
I
Reset Switch – This signal (ground) provided from external reset switch.
-
Not connected (Keyboard Switch)
I/O
Keyboard Data – Data signal provided to external keyboard connector.
I/O
Keyboard Clock – Clock signal provided to external keyboard connector.
I
Keyboard Ground
O
Keyboard Power – This +5 volts is provided to external keyboard
connector. Requires external fuse for keyboard/mouse protection.
I
Backup Battery – This connection provides an additional backup battery
from an external source. It can also be used in place of the on-board
backup battery, B1, shipped with all LittleBoard 800s. Each RTS battery
input is protected with a zener diode.
I
Battery - Return (Grounded)
Reference Manual
Hardware
LittleBoard 800
Advertisement
Table of Contents
