ADLINK Technology LittleBoard 735, Справочное руководство

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Chapter 3 Hardware
LittleBoard 735 Reference Manual 27
Note: The shaded areas denote power or ground. The signals marked with * = Negative true logic.
Utility 2 Interface
The Utility 2 (J13) interface consists of a 24-pin header used to route various signals to an external board
with external connections, or directly to the respective device such as the mouse and power button.
Table 3-
9 lists the pin signals of the Utility 2 interface. The J13 header uses 24 pins, 2 rows, odd/even (1, 2) pin
sequence with 0.100" (2.54mm) pitch.
•
PS/2 Mouse signals
•
SMBus signals
•
Power button signal
System Management Bus (SMBus)
The I/O Hub, 82801GBM (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 header
(J13). The master contained in the 82801GBM is used to communicate with the SDRAM DDR2 SODIMM,
82574IT Gigabit Ethernet controller, and the clock generator. Table 3-8 lists the corresponding binary
addresses of these devices on the SMBus.
Table 3-7. Utility 1 Interface Pin Signals (J15)
Pin # Signal I/O Description
1 NC - Not connected (-12V Power)
2 GND I Ground
3 NC - Not connected (-5V Power)
4 GND I Ground
5 LED O Power-On LED – This on-board +3.3 volts is provided through 330 ohm
resistor to an external Power-On LED.
6 NC - Not connected (Power Good)
7 SPKR+ O + Speaker Output – This signal drives external PC "Beep" speaker.
8 GND I Ground
9 RSTSW* I Reset Switch – This signal (ground) provided from external reset switch.
10 NC - Not connected (Keyboard Switch)
11 KBDATA I/O Keyboard Data – Data signal provided to external keyboard connector.
12 KBCLK I/O Keyboard Clock – Clock signal provided to external keyboard connector.
13 GND I Keyboard Ground
14 KBDPWR O Keyboard Power – This +5 volts is provided to external keyboard
connector. Requires external fuse for keyboard/mouse protection.
15 BATV+ 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 735s. Each RTS battery
input is protected with a zener diode.
16 BATV- I Battery - Return (Grounded)