82801CA Datasheet, PDF (55/521 Pages) Intel Corporation – I/O Controller Hub 3-S (ICH3-S)

Power Planes and Pin States
Power Planes and Pin States
3
3.1
This chapter provides the 82801CA ICH3-S power plane and pin states.
Power Planes
Table 3-1. Intel^® ICH3 Power Planes
Plane
Main I/O
(3.3 V)
Main Logic
(1.8 V)
Resume I/O
(3.3 V Standby)
Resume Logic
(1.8 V Standby)
CPU I/F
(1.3 ~ 2.5V)
RTC
Description
Vcc3_3: Powered by the main power supply or battery. When the system is in the S3,
S4, S5, or G3 state, this plane is assumed to be shut off.
Vcc1_8: Powered by the main power supply or battery. When the system is in the S3,
S4, S5, or G3 state, this plane is assumed to be shut off.
VccSUS3_3: Powered by the main power supply or battery in S0–S1 states. Powered
by the trickle power supply or main battery When the system is in the S3, S4, S5, state.
Assumed to be shut off only when in the G3 state (system is unplugged).
VccSUS1_8: Powered by the main power supply or battery in S0–S1 states. Powered
by the trickle power supply or main battery when the system is in the S3, S4, S5, state.
Assumed to be shut off only when in the G3 state (system is unplugged).
V_CPU_IO: Powered by the main power supply or battery via processor voltage
regulator. When the system is in the S3, S4, S5, or G3 state, this plane is assumed to
be shut off.
VccRTC: When other power is available (from the main supply or main battery¹),
external diode coupling will provide power to reduce the drain on the RTC battery.
Assumed to operate from 3.3 V down to 2.0 V.
Intel^® 82801CA ICH3-S Datasheet
3-55