Intel 820E Manual De Usuario

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Intel
®
 820E Chipset 
 
 
 
 
R
 
104  
Design 
Guide 
2.22.1.1. Bus 
Topologies 
The LAN Connect Interface can be configured in several topologies, as follows: 
• 
Direct point-to-point connection between the ICH2 and the LAN component 
• 
Dual footprint (see Section 2.22.6.) 
• 
LOM/CNR implementation 
2.22.1.2. Point-to-Point 
Interconnect 
The following are guidelines for a single-solution motherboard. Either the Intel
 
82562EH component, 
Intel
 
82562ET component or CNR is installed. 
Figure 65. Single-Solution Interconnect 
IO_subsys_single_sol_interconn
ICH2
Platform LAN
Connect
(PLC)
LAN_TXD[2:0]
LAN_RXD[2:0]
LAN_RSTSYNC
LAN_CLK
L
 
Length requirements for Figure 65: 
Intel 82562EH:  L = 4.5 inches to 10.0 inches (Signal lines LAN_RXD[2:1] and LAN_TXD[2:1] are 
not connected.) 
Intel 82562ET:  L = 3.5 inches to 10.0 inches 
CNR*:  L = 3.0 inches to 9.0 inches (0.5 inch to 3.0 inches on card) 
2.22.1.3. LOM/CNR 
Interconnect 
 
The following guidelines enable an all-inclusive motherboard solution. This layout combines the LOM, 
dual footprint, and CNR solutions. The resistor pack ensures that either a CNR option or a LAN-on-
motherboard option can be implemented at one time. The following figures show a model of this. The 
recommended trace routing lengths are shown in Table 23.