Figure 80. Command Signal To Sck/Sck# Trace Length Matching Requirements - Intel 855PM Design Manual

System Memory Design Guidelines (DDR-SDRAM)

Figure 80. Command Signal to SCK/SCK# Trace Length Matching Requirements

= Motherboard Trace Lengths
Intel 855PM
MCH Package
Note: CMD Lengths are measured from MCH-M
pins to SO-DIMM0 connector pads.
= Motherboard Trace Lengths
Intel 855PM
MCH Package
Note: CMD Lengths are measured from MCH-M
pins to SO-DIMM1 connector pads.
142
SO-DIMM0
SMA[12:0],
SBS[1:0],
RAS#, CAS#,
WE#
SCK[2:0]
SCK#[2:0]
SO-DIMM0 SO-DIMM1
SMA[12:0],
SBS[1:0],
RAS#, CAS#,
WE#
SCK[5:3]
SCK#[5:3]
Intel
CMD Length = Y
( Y - 1.0" ) < = X < = ( Y + 0.5" )
SCK/SCK#[2:0] Length = X
CMD Length = Y
( Y - 1.0" ) < = X < = ( Y + 0.5" )
SCK/SCK#[5:3] Length = X
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855PM Chipset Platform Design Guide
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