Other Gmch Reference Voltage And Analog Power Delivery; Gmch Gtlvref - Intel 855GME Design Manual

®
Intel 855GME Chipset and Intel
4.8.3

Other GMCH Reference Voltage and Analog Power Delivery

4.8.3.1

GMCH GTLVREF

For GMCH, the GTLREF generation circuit has been broken down into three separate voltage
references: host data reference voltage (HDVREF[2:0]), host address reference voltage (HAVREF)
and host common clock reference voltage (HCCVREF). Maximum length from pin to voltage
divider for each reference voltage shall be less than 0.5 inches. Ten-mil wide traces are
recommended. GMCH VREF may be maintained as individual voltage dividers as shown in
Figure 55,
Figure 55. GMCH HDVREF[2:0] Reference Voltage Generation Circuit
+VCCP
R1
49.9
1%
R2
100
1%
Figure 56. GMCH HAVREF Reference Voltage Generation Circuit
+VCCP
R1
49.9
1%
R2
100
1%
Figure 56, and Figure 57.
GMCH_HDVREF
C1 C2
1uF 0.1uF
GMCH_HAVREF
C3
C1
1uF
0.1uF
January 2007
®
6300ESB ICH Embedded Platform Design Guide
Intel
K21
HDVREF0
J21
HDVREF1
J17
HDVREF2
Y22
HAVREF
Intel
®
855GME
®
855GME
Chipset
113