Guide

Hub Interface

150 Intel

852GM Chipset Platform Design Guide

Figure 69. ICH4-M Locally Generated Reference Voltage Divider Circuit

ICH4

HIREF

VCCHI

HI_VSWING

9.3.2.2. GMCH Single Generated Voltage Reference Divider Circuit

This option allows the GMCH to use one voltage divider circuit to generate both HLVREF and

HLPSWING voltage references. The reference voltage for both HLVREF and HLPSWING must meet

the voltage specification in Table 61. The resistor values R1, R2, and R3 must be rated at 1% tolerance

(see Table 62). Normal care needs to be taken to minimize crosstalk to other signals (< 10-15 mV). If

the voltage specifications are not met, then individually generated voltage divider circuits for HLVREF

and PSWING is required.

Figure 70. GMCH Locally Generated Reference Voltage Divider Circuit

GMCH

HLVREF

VCCHI

PSWING

9.3.3. Separate GMCH and ICH4-M Voltage Divider Circuits for VREF

and VSWING

Sections 9.3.3.1 and 9.3.3.2 provide the option to generate individual voltage reference for VREF and

VSWING separately for GMCH and ICH4-M.

9.3.3.1. Separate ICH4-M Voltage Divider Circuits for HIVREF and HI_VSWING

This option allows for tuning the voltage references HIVREF and HI_VSWING individually. The

reference voltage for both HIVREF and HI_VSWING must meet the voltage specification in Table 61.

Normal care needs to be taken to minimize crosstalk to other signals (< 10-15 mV).