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Chapter 3
Table 3-17. SMBus Reserved Addresses
Component
Serial EEPROM (SEEP)
SDRAM EPROM
Clock Generator (ICS9250)
Southbridge (VT82C686B)
Thermal Sensor (MAX1617)
USB Signals (USB0 and USB1)
The LittleBoard 700 contains one root USB hub with four functional USB ports. This connector
(Utility 2 ) provides two of the four USB ports (USB0 and USB1). The hub is USB v.1.1 and Intel
Universal HCI v.1.1 compatible.
Features implemented in the USB ports include the following:
•
One root hub and two USB ports on this connector
•
USB v.1.1 and Intel Universal HCI v.1.1 compatible
•
Integrated physical layer transceivers
•
Over-current detection status (software) on all four USB ports
• Over-current fuses for all four ports on the LB 700 board. See Table 2-3.
NOTE
Ampro does not recommend connecting a USB boot device to the
LittleBoard 700 through an external hub. Instead, connect the USB
boot device directly to the LittleBoard 700. Refer to Chapter 4, BIOS
Setup for more information.
Infrared Port (IrDA)
The Infrared Data Association (IrDA) port provides a two-way wireless communications port using
infrared as a transmission medium at the basic level. There are two basic infrared implementations
provided; the Hewlett-Packard Serial Infrared (HPSIR) and the Amplitude Shift Keyed Infrared
(ASKIR) methods. HPSIR is a serial implementation of infrared developed by Hewlett-Packard. The
IrDA (HPSIR and ASKIR) signals share Serial Port 2 with the modem and RS232 functions on the port.
This port can be enabled/disabled and configured for HPSIR or ASKIR signals in BIOS Setup. Refer to
Chapter 4, BIOS Setup for more information.
The HPSIR method allows serial communication at baud rates up to 115k baud. Each word is sent
serially beginning with a zero value start bit. A zero is sent when a single infrared pulse is sent at the
beginning of the serial bit time. A one is sent when no infrared pulse is sent during the bit time.
The Amplitude Shift Keyed infrared (ASKIR) allows serial communication at baud rates up to 19.2k
baud. Each word is sent serially beginning with a zero value start bit. A zero is sent when a 500kHz
waveform is sent for the duration of the serial bit time. A one is sent when no transmission is sent
during the serial bit time.
Both of these methods require an understanding of the timing diagrams provided in the Southbridge and
Super I/O controller chip (VT82C686B) specifications available from the manufacture's web site and
referenced earlier in this manual. For more information, refer to the VIA VT82C686B chip databook
and the Infrared Data Association web site at http://www.irda.org.
NOTE
For faster speeds and infrared applications not covered in this brief description,
refer to the VT82C686B chip specifications by VIA Technologies, Inc.
46
Address Binary
1010,010x
b
1010,000x
b
1101,001x
b
0000,000x
(default) Programmable Master
b
0011,0010x
b
Reference Manual
Hardware
LittleBoard 700
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