January 2007
309
Intel
®
855GME Chipset and Intel
®
6300ESB ICH Embedded Platform Design Guide
Layout Checklist
SMA[5,4,2,1]
SMAB[5,4,2,1]
•
See a detailed discussion on this topic in
•
Route with trace impedance 55
Ω
± 15%
using 2:1 spacing.
•
Isolation from non-DDR signals should be
20 mils.
•
GMCH pad to DIMM trace length limits are
2 to 6 inches.
•
Place parallel termination resistor within 2
inches of the DIMM pad.
•
Overall min/max length to the DIMM must
comply with clock length matching
requirements.
•
Maximum recommended via count per
signal is 3.
•
Refer to the detailed routing
guidelines in
.
RCVENIN#
RCVENOUT#
•
Internally shunted on Intel 855GME
chipset - no external connection
necessary.
•
Recommendation is that both signals be
transitioned to the secondary side with
vias next to the package balls to facilitate
probing.
•
Refer to the detailed routing
guidelines in
.
DDR System Memory Decoupling
GMCH VCCSM
Decoupling
•
Requires a minimum of (11) 0603, 0.1 µF
caps placed within 150 mils of the GMCH
package.
•
Distribute evenly along the DDR memory
interface, placed perpendicular to the
GMCH with the power side of the caps
facing the GMCH.
•
Each GMCH ground and VCCSM power
ball should have its own via.
•
Each via should be as close to the
associated cap pad as possible, within 25
mils and with as thick a trace as possible.
•
Two 150
μ
F caps between GMCH and 1st
DIMM.
•
Refer to
for more
information.
DDR VDD
Bypass Caps
•
Place 9 evenly spaced 0.1 µF 0603 caps
between the DIMMs.
•
A wide trace from each cap should
connect to a via that transitions to the
ground plane layer.
•
A wide trace should connect the 2.5 V side
of each cap to a via that transitions to the
2.5 V plane, each via placed as close to
the cap pad as possible.
•
Each cap should also connect to the
closest 2.5 V DIMM pin on either DIMM
connector with a wide trace.
•
Four 100 - 150
μ
F caps near the DIMMs.
•
Helps minimize return path
discontinuities.
•
Refer to
for more
information.
Table 149. Intel
®
855GME Chipset GMCH Layout Checklist (Sheet 3 of 6)
Checklist Items
Recommendations
Comments
Summary of Contents for 6300ESB ICH
Page 24: ...24 Intel 855GME Chipset and Intel 6300ESB ICH Embedded Platform Design Guide Introduction...
Page 102: ...102 Intel 855GME Chipset and Intel 6300ESB ICH Embedded Platform Design Guide...
Page 122: ...122 Intel 855GME Chipset and Intel 6300ESB ICH Embedded Platform Design Guide...
Page 190: ...190 Intel 855GME Chipset and Intel 6300ESB ICH Embedded Platform Design Guide Hub Interface...
Page 318: ...318 Intel 855GME Chipset and Intel 6300ESB ICH Embedded Platform Design Guide Layout Checklist...
