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