Core Logic Voltage (V1P2); Ia-32 Core Frequency And Power Select (Bsel/V_Sel); Ddr2 Voltage (V1P8_Ddr); Ddr2 Termination Voltage (Ddr2_Vtt) - Intel EP80579 Manual

drain (OD) I/O, hence, it requires an external 10K pull-up. It should be noted that the
V_SEL signal can also be pulled down to GND to configure a 1.2GHz SKUed part (BSEL/
V_SEL = "11") to operate as a 1.066GHz SKUed part (BSEL/V_SEL = "10").
Table 12.

IA-32 core Frequency and Power Select (BSEL/V_SEL)

SKU ID
5/6
3/4/7
--
1/2/8
6.5.2

Core Logic Voltage (V1P2)

The V1P2 (1.2V) power plane is derived from the 5V power rail delivered by the power
supply unit through a switching regulator. It powers the EP80579 core logic and the
I/O buffer cells for SATA, PCI Express, and Expansion Bus interfaces.
6.5.3

DDR2 Voltage (V1P8_DDR)

The V1P8_DDR (1.8V) power plane is used to provide power to the DDR2 DRAM core
and the DDR2 I/O ring. The V1P8_DDR power plane is created using a combination of a
switching and linear regulator. The regulator switches between a switching power
supply in S0 state and a linear regulator in S3 state. The switching regulator required
for S0 receives its input directly from the 5V power rail from the ATX power supply unit.
The linear regulator receives its input directly from the 5V Standby Voltage output
(VSBY5) from the ATX power supply unit.
6.5.4

DDR2 Termination Voltage (DDR2_VTT)

The DDR2_VTT (0.9V) is for the DDR2 termination voltage. The input voltage for the
DDR2_VTT regulator must come from the 1.8V DDR (V1P8_DDR) core regulator. The
VTT voltage regulator is a switching regulator that regulates the 1.8V DDR2 core
voltage down to the 0.9V reference voltage +/- 40mV. This provides common mode
noise rejection between the DDR2 termination and I/O voltages.
6.5.5 1.8V Voltage (V1P8)
The V1P8 (1.8V) is a 1.8V power supply isolated from the V1P8_DDR. This voltage is
used by the on-board components (Flash, HSS) that require 1.8V power supply but
cannot be connected to the DDR2 power supply. The V1P8 power plane is derived from
the 3.3V power rail delivered by the power supply unit through a linear regulator.
6.5.6

GbE 2.5V (V2P5)

The V2P5 (2.5V) power plane is derived from the +12V power rail delivered by the
power supply unit through adjustable shunt regulators. This voltage is used by the GbE
controller and LAN transceivers.
®
Intel EP80579 Integrated Processor Product Line
Platform Design Guide
70
®
Intel EP80579 Integrated Processor Product Line—System Power Delivery Guide
Manufacturing
Frequency SKU BSEL
(FSB/Intel Value
Architecture MHz)
533/1200 1
533/1200 1
533/1066 1
-- 0
400/600 0
Operating
V_SEL Frequency
Value (FSB/IA-32 core
MHz)
1 533/1200
0 533/1066
0 533/1066
1 Reserved
0 400/600
Order Number: 320068-005US
IA-32 core
Voltage
1.30V
1.30V
1.30V
--
1.0V
May 2010