Intel 820E Benutzerhandbuch

50  

Design 

Guide 

MCH

Signal on secondary side

Signal on primary side

Signal A

Signal B

Signal A

Signal B

rsl_sig-lay_alter.vsd

Route on EITHER layer.

Ground isolation is

REQUIRED!

Te
rm

 

Method 1 

Primary side 

Secondary side 

Method 2 

Secondary side 

Primary side 

To allow for greater routing flexibility, the RSL signals require pad-to-pin length matching between the 
MCH and the first connector. If the trace lengths are matched between the balls of the MCH and the pin 
of the RIMM connector, the length mismatch between the pad (on the die) and the ball has not been 
taken into account. However, given the package dimension, which represents the length from the pad to 
the ball, the routing can compensate for this package mismatch. Therefore, the board length mismatch 
can be increased.  

The RSL channel requires the matching of the trace lengths from pad to pin within ±10 mils. 

Given the following definitions: 

• 

Package dimension: Representation of length from pad to ball 

• 

Board trace length: Trace length on board 

• 

Nominal RSL length: Length to which all signals are matched. (Note: There is not necessarily a 
trace that is exactly to nominal length, but all RSL signals must be matched to within ±10 mils of 
the nominal length.) The nominal RSL length is an arbitrary length, within the limits of the routing 
guidelines, to which all the RSL signals will be matched (within 10 mils).