Datasheet

Electrical Characteristics
150 Intel
®
82845G/82845GL/82845GV GMCH Datasheet
6.5 DC Parameters
NOTES:
1. HA_VREF/HD_VREF and HCC_VREF are generically referred to as GTLREF throughout the rest of this
document.
2. HI_VREF and HI_SWING are set according to the nominal VCC.
3. The DC specifications are intended solely for DC measurements and do not comprehend any AC noise
components.
Table 6-5. DC Operating Characteristics
Signal Name Parameter Min Nom Max Unit
I/O Buffer Supply Voltage
VCC Core Voltage 1.425 1.5 1.575 V
VCCAGP AGP I/O Voltage 1.425 1.5 1.575 V
VCCHI Hub Interface I/O Voltage 1.425 1.5 1.575 V
VCCA_DAC DAC Supply Voltage 1.425 1.5 1.575 V
VTT
Host AGTL+ Termination
Voltage
1.15 N/A 1.75 V
VCCSM(DDR) DDR I/O Supply Voltage 2.375 2.5 2.625 V
VCCSM(SDR) SDR I/O Supply Voltage 3.135 3.3 3.465 V
Reference Voltages
AGP_VREF AGP Reference Voltage
1/2 VCCAGP
– 2%
1/2 x
VCCAGP
1/2 VCCAGP
+ 2%
V
HI_VREF
Hub Interface Reference
Voltage
0.343 0.35 0.357 V
HI_SWING
Hub Interface Compensation
Reference Voltage
0.686 0.7 0.714 V
HA_VREF/
HD_VREF
Host Address and Data
Reference Voltage
2/3 x VTT – 2% 2/3 x VTT 2/3 x VTT + 2% V
HX_SWING/
HY_SWING
Host Compensation
Reference Voltage
1/3 x VTT – 2% 1/3 x VTT 1/3 x VTT + 2% V
HCC_VREF
Host Common Clock
Reference Voltage
2/3 x VTT – 2% 2/3 x VTT 2/3 x VTT + 2% V
SM_VREF
(DDR)
DDR Reference Voltage
0.5 VCCSM
(DDR) – 2%
1/2 x VCCSM
(DDR)
0.5 VCCSM
(DDR) + 2%
V
SM_VREF
(SDR)
SDR Reference Voltage
0.5 VCCSM
(SDR) – 2%
1/2 x VCCSM
(SDR)
0.5 VCCSM
(SDR) + 2%
V