Intel 855GME Design Manual page 185

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Intel 855GME Chipset and Intel
Note: HIREF and HI_VSWING is derived from 1.5 V which is the nominal core voltage for the
6300ESB. Voltage supply tolerance for driver voltage must be within a
The selected resistor values ensure that the reference voltage tolerance is maintained over the input
leakage specification. The maximum distance from divider to device is four inches (less is better).
Normal care needs to be taken to minimize crosstalk to other signals (< 10-15 mV). When the
single HIREF/HI_VSWING divider circuit is located more than four inches away, then the locally
generated reference divider should be used. Below are four examples of the HIREF/HI_VSWING
divider circuit.
Figure 86. 8-Bit Hub Interface Single HIREF/HI_VSWING Generation Circuit Option A
1. Two 0.1 µF capacitors (C1 and C3) should be placed close to the divider.
2. Each 0.01 µF bypass capacitor (C2, C4, C5, and C6) should be placed within 0.25 inches of HIREF/VREF
pin (for C4 and C6) and HI_VSWING pin (for C2 and C5).
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6300ESB ICH Embedded Platform Design Guide
January 2007
Hub Interface
±
5% range of nominal.
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