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Intel
®
855GME Chipset and Intel
®
6300ESB ICH Embedded Platform Design Guide
System Memory Design Guidelines (DDR-SDRAM)
5.4.4.5 SDQ/SDQS Signal Package Lengths
The package length data in Table 34 shall be used to tune the length of each SDQ, SDM, and SDQS
motherboard trace as required to achieve the overall length matching requirements defined in the
prior sections.
Figure 68. SDQ/SDM to SDQS Trace Length Matching Diagram
GMCH Package
Note: All lengths are measured from GMCH die
pad to DIMM connector pad.
SDQ[6]
SDQ[7]
SDQ Length (Y) = (X ±25 mils)
SDQ Length (Y) = (X ±25 mils)
SDQS Length = X
DIMM0
DIMM1
GMCH Package
(X +/-25 mils)
(X +/-25 mils)
SDQS Length =
X
ote: All lengths are measured from GMCH die-
ad to DIMM connector pads.
855GME
Die
855GME
Die
SDM Length (Y) = (X ±25 mils)
(X ±25 mils)
Note: Only one byte lane is shown for
reference. Each byte lane is matched
iIndependently.