Separate Gmch Voltage Divider Circuits For Hlvref And Pswing; Recommended Resistor Values For Single Vref/Vswing Divider Circuit; Recommended Resistor Values For Hlvref And Pswing Divider Circuits For Gmch - Intel 855GME Design Manual

®
Intel 855GME Chipset and Intel
Hub Interface
Table 69. Recommended Resistor Values for Single VREF/VSWING Divider Circuit
Option 1
Option 2
Option 3
8.1.4.2

Separate GMCH Voltage Divider Circuits for HLVREF and PSWING

This option allows for tuning the voltage references HLVREF and PSWING individually. The
reference voltage for both HLVREF and PSWING must meet the voltage specification in
Normal care needs to be taken to minimize crosstalk to other signals (< 10-15 mV).
depicts the individual HLVREF and PSWING voltage reference divider circuits for GMCH.
Table 70
GMCH.
Figure 91. Individual HLVREF and PSWING Voltage Reference Divider Circuits for GMCH
Table 70. Recommended Resistor Values for HLVREF and PSWING Divider Circuits for GMCH
Signal Name
HLVREF
(350 mV)
PSWING
(800 mV)
188
®
6300ESB ICH Embedded Platform Design Guide
Recommended Resistor Values
R1 = 80.6 Ω ± 1%
R1 = 255 Ω ± 1%
R1 = 226 Ω ± 1%
C1 and C3 = 0.1 µF (near divider)
C5, C6 = 0.01 µF (near component)
presents the recommended resistor values for HLVREF and PSWING divider circuits for
GMCH
Recommended Resistor Values
R4 = 287 Ω ± 1%
R5 = 100 Ω ± 1%
R6 = 68.1 Ω ± 1%
R7 = 100 Ω ± 1%
R2 = 51.1 Ω ± 1% R3 = 40.2 Ω ± 1%
R2 = 162 Ω ± 1% R3 = 127 Ω ± 1%
R2 = 147 Ω ± 1% R3 = 113 Ω ± 1%
V HI
CC
R4
PSWING
HLVREF
R5
C6
C5
VCCHI
VCCHI=1.35 V
VCCHI=1.35 V
VCCHI
1.5 V
1.5 V
1.5 V
Table
Figure 91
R6
R7
C3 C1
Capacitor
C3 = 0.1 µF (near divider);
C6 = 0.01 µF (near component)
C1 = 0.1 µF (near divider)
C5 = 0.01 µF (near component)
70.