January 2007
311
Intel
®
855GME Chipset and Intel
®
6300ESB ICH Embedded Platform Design Guide
Layout Checklist
GCLKIN
•
Place series resistor close to CK409,
within 500 mils.
•
Total trace length range is 4 to 9 inches.
•
Minimum spacing 20 mils.
•
Overall length of CLK66 is considered the
reference length for all other CLK66 and
CLK33, except USBCLK and CLK14.
•
The length of CLK66 traces should be
matched within ± 100 mils and then used
as the basis for defining the length of all
other length matched clocks.
•
Refer to CLK66 clock group routing
guidelines detailed in
RSTIN#
•
Connect to PCIRST# output of the
6300ESB.
GMCH Decoupling, VREF, and Filtering
HLRCOMP
HLVREF
PSWING
•
GMCH HLRCOMP signal should be
strapped to 1.2 V via 27.4
Ω
± 1%
HLRCOMP resistor with trace impedance
55
Ω
± 15%.
•
HLVREF and PSWING voltage
requirements must be set appropriately for
proper hub interface operation. The case
is similar for HIREF and HIVSWING
signals on 6300ESB.
•
Refer to
for HI specific
voltage requirements and several
options for voltage divider circuits.
HXRCOMP
HYRCOMP
•
Each signal should be pulled to ground
with a 27.4
Ω
± 1% resistor.
•
Max trace length to the resistor should be
less than 0.5 inches and should be 18 mils
wide to achieve the characteristic
impedance target of 27.4
Ω
.
•
Maintain 25 mil separation from any
switching signals.
•
This signal is used to calibrate the
Host AGTL+ I/O buffers
characteristics to specific board
characteristics.
•
Refer to
for more
information.
HDVREF[2:0]
HAVREF
HCCVREF
•
Max length from pin to voltage divider for
each reference voltage should be less
than 0.5 inches.
•
10 mil traces are recommended.
•
To provide constant and clean power
delivery to the data, address, and
common clock signals of the host
AGTL+ interface.
•
Refer to
for
recommended individual voltage
divider circuits.
Table 149. Intel
®
855GME Chipset GMCH Layout Checklist (Sheet 5 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...
