Intel III Xeon 500 MHz 80525KX5001M User Manual
Product codes
80525KX5001M
Pentium
®
III Xeon™ Processor at 500 and 550 MHz
16
Datasheet
2.5
Voltage Identification
The Pentium
III
Xeon processor contains five voltage identification pins for core voltage selection
and five voltage identification pins for L2 cache voltage selection. These pins may be used to
support automatic selection of both power supply voltages. VID_CORE[4:0] controls the voltage
supply to the processor core and VID_L2[4:0] controls the voltage supply to the L2 cache. Both
use the same encoding as shown in
support automatic selection of both power supply voltages. VID_CORE[4:0] controls the voltage
supply to the processor core and VID_L2[4:0] controls the voltage supply to the L2 cache. Both
use the same encoding as shown in
. They are not driven signals, but are either an open
circuit or a short circuit to V
SS
. The combination of opens and shorts defines the voltage required
by the processor core and L2 cache. The VID pins support variations in processor core voltage
specifications and in L2 cache implementations among processors in the Pentium
specifications and in L2 cache implementations among processors in the Pentium
III
Xeon
processor family.
shows the recommended range of values to support for both the processor
core and the L2 cache. A ‘1’ in this table refers to an open pin and ‘0’ refers to a short to ground.
The definition provided below is a superset of the definition previously defined for the Pentium Pro
processor (VID4 was not used by the Pentium Pro processor) and is common to the Pentium II,
Pentium II Xeon processor, and Pentium
The definition provided below is a superset of the definition previously defined for the Pentium Pro
processor (VID4 was not used by the Pentium Pro processor) and is common to the Pentium II,
Pentium II Xeon processor, and Pentium
III
Xeon processors. The power supply must supply the
voltage that is requested or it must disable itself.
To ensure the system is ready for all Pentium
III
Xeon processors, a system should support those
voltages indicated with a bold x in
. Supporting a smaller range will risk the ability of the
system to migrate to possible higher performance processors in the future. Support for a wider
range provides more flexibility and is acceptable.
range provides more flexibility and is acceptable.
Table 2. Core and L2 Voltage Identification Definition
1, 2
(Sheet 1 of 2)
Processor Pins
VID4
VID3
VID2
VID1
VID0
V
CC
Core
3
L2
3
00110b - 01111b
Reserved
0
0
1
0
1
1.80
x
x
0
0
1
0
0
1.85
x
x
0
0
0
1
1
1.90
x
x
0
0
0
1
0
1.95
x
x
0
0
0
0
1
2.00
x
x
0
0
0
0
0
2.05
x
x
1
1
1
1
0
2.1 x
x
1
1
1
0
1
2.2 x
1
1
1
0
0
2.3 x
1
1
0
1
1
2.4
x
1
1
0
1
0
2.5 x
1
1
0
0
1
2.6
x
1
1
0
0
0
2.7
x
1
0
1
1
1
2.8 x
1
0
1
1
0
2.9
1
0
1
0
1
3.0
1
0
1
0
0
3.1
1
0
0
1
1
3.2
1
0
0
1
0
3.3