Compensation; Figure 54. Single-Hub-Interface Reference Divider Circuit; Figure 55. Locally Generated Hub Interface Reference Dividers - Intel 815 Design Manual

R

Figure 54. Single-Hub-Interface Reference Divider Circuit

Figure 55. Locally Generated Hub Interface Reference Dividers

GMCH
HUBREF
9.1.4

Compensation

Independent hub interface compensation resistors are used by the GMCH and ICH to adjust buffer
characteristics to specific board characteristics. Refer to the Intel
Graphics and Memory Controller Hub (GMCH) for use with the Universal Socket 370 Datasheet
and the Intel
compensation. The resistive compensation (RCOMP) guidelines are as follows:
RCOMP: Tie the HLCOMP pin of each component to a 40
1.85V) via a 10-mil-wide, 0.5 inch trace (targeted at a nominal trace impedance of 40 ). The
GMCH and ICH each requires their own RCOMP resistor.
®
Intel 815 Chipset Platform Design Guide
300
GMCH
HUBREF
0.01 µF
300
1.85 V
300
300
®
82801AA (ICH) and 82801AB (ICH0) I/O Controller Hub Datasheet for details on
1.85 V
0.01 µF
0.1 µF
1.85 V
0.01 µF 0.01 µF
®
Hub Interface
ICH
HUBREF
hub_IF_ref_div_1
300
ICH
HUBREF
300
hub_IF_ref_div_2
815 Chipset Family: 82815
1% or 2% pull-up resistor (to
109