Technical Reference
49
2.2.2.5 Front Panel USB Header
Figure 12 is a connection diagram for the front panel USB header.
NOTE
• The +5 V DC power on the USB header is fused.
• Use only a front panel USB connector that conforms to the USB 2.0 specification for
high-speed USB devices.
Figure 12. Connection Diagram for the Front Panel USB Header
2.2.2.6 Low Pin Count (LPC) Debug Header
During the POST, the BIOS generates diagnostic progress codes (POST codes) to I/O
port 80h. If the POST fails, execution stops and the last POST code generated is left
at port 80h. This code is useful for determining the point where an error occurred
(refer to Section 4.5 on page 67 for a description of the POST codes).
Displaying the POST codes requires a POST card that can interface with the Low Pin
Count (LPC) Debug header. The POST card can decode the port and display the
contents on a medium such as a seven-segment display.
Table 24. LPC Debug Header
Pin Signal Name Pin Signal Name
1 CK_33M_DEBUG 2 GND
3 PLTRST# 4 LFRAME#
5 LAD0 6 LAD1
7 LAD2 8 LAD3
9 GND 10 GND
11 +3.3 V 12 +3.3 V
13 Not connected 14 +3.3 V