Chapter 3 Hardware
24 Reference Manual XTX 820
Universal Serial Bus (USB)The XTX 820 COM supports up to six USB ports on the baseboard and the supported features are listed
below.
•USB v2.0 backward compatible to legacy v.1.1
•Two root hubs and 4 ports on J1
•Two ports and 1 root hub on J2
•Supports USB boot of floppy disk drives, hard disk drives, CD-ROMs, or other USB boot devices
•Integrated physical layer transceivers
•Over-current detection status on USB ports 1 and 2
Table 3-5. Simplified USB Interface Pin/Signal Descriptions (J1)
J1
Pin # Signal Description
USBP USB Power –
76 USB0- Universal Serial Bus Port 0 Data Negative Polarity
88 USB0+ Universal Serial Bus Port 0 Data Positive Polarity
80 USB1- Universal Serial Bus Port 1 Data Negative Polarity
92 USB1+ Universal Serial Bus Port 1 Data Positive Polarity
58 USB2- Universal Serial Bus Port 2 Data Negative Polarity
66 USB2+ Universal Serial Bus Port 2 Data Positive Polarity
62 USB3- Universal Serial Bus Port 3 Data Negative Polarity
72 USB3+ Universal Serial Bus Port 3 Data Positive Polarity
GND USB Port ground
Note: The shaded area denotes power or ground.
Serial Interrupt RequestThis SERIRQ signal is connected to serial request input on the I/O Hub (Southbridge) chip (82801FBM)
for the alternative LPC/PCI interrupts. If this feature is supported, then DMA2 (DAck2 and DRQ2)
shall not be supported by XTX 820 module.
Table 3-6. Simplified Serial Interrupt Request (J1)
J1 Pin # Signal Description
21 SERIRQ Serial Interrupt Request – This pin is used to support the serial interrupt protocol.
AC’97 SoundThe XTX 820 module supports the AC’97 audio standard and the supported features are listed below.
•Provides Realtek ALC 655, AC'97/HDA (High Definition Audio CODECs)
•AC’97 Rev 2.2 compliant
•Supports audio amplifier on baseboard
•PC-Beep passthrough to Line Out while reset is held active low
•True Line Level Output with volume control independent of Line Out
•Digital 3V and 5V compliant