
11-7
ELECTRICAL SPECIFICATIONS
11.5.2.
Mixing Processors of Different Frequencies
Mixing components of different internal clock frequencies is not supported and has not been val-
idated by Intel. One should also note when attempting to mix processors rated at different fre-
quencies in a multi-processor system that a common bus clock frequency and a set of multipliers
must be found that is acceptable to all processors in the system. Of course, a processor may be
run at a core frequency as low as its minimum rating. Operating system support for multi-
processing with mixed frequency components should also be considered.
Note that in order to support different frequency multipliers to each processor, the design shown
above would require four multiplexers.
11.6.
VOLTAGE IDENTIFICATION
There are 4 Voltage Identification Pins on the Pentium Pro processor package. These pins can
be used to support automatic selection of power supply voltages. These pins are not signals but
are each either an open circuit in the package or a short circuit to Vss. The opens and shorts de-
fines the voltage required by the processor. This has been added to cleanly support voltage spec-
ification variations on future Pentium Pro processors. These pins are named VID0 through VID3
and the definition of these pins is shown in Table 11-1. A ‘1’ in this table refers to an open pin
and ‘0’ refers to a short to ground. The VccP power supply should supply the voltage that is
requested or disable itself.
NOTES:
1. Nominal setting requiring regulation to
±
5% at the Pentium
®
Pro processor pins under all conditions. Sup-
port not expected for 2.1V-2.3V.
2. 1= Open circuit; 0= Short to Vss
Table 11-1. Voltage Identification Definition1, 2
VID[3:0]
Voltage setting
VID[3:0]
Voltage Setting
0000
3.5
1000
2.7
0001
3.4
1001
2.6
0010
3.3
1010
2.5
0011
3.2
1011
2.4
0100
3.1
1100
2.3
0101
3.0
1101
2.2
0110
2.9
1110
2.1
0111
2.8
1111
No CPU Present
Содержание Pentium Pro Family
Страница 17: ...1 Component Introduction ...
Страница 26: ...2 Pentium Pro Processor Architecture Overview ...
Страница 27: ......
Страница 36: ...3 Bus Overview ...
Страница 62: ...4 Bus Protocol ...
Страница 105: ...5 Bus Transactions and Operations ...
Страница 126: ...6 Range Registers ...
Страница 131: ...7 Cache Protocol ...
Страница 135: ...8 Data Integrity ...
Страница 148: ...9 Configuration ...
Страница 161: ...10 Pentium Pro Processor Test Access Port TAP ...
Страница 172: ...11 Electrical Specifications ...
Страница 201: ...12 GTL Interface Specification ...
Страница 229: ...13 3 3V Tolerant Signal Quality Specifications ...
Страница 233: ...14 Thermal Specifications ...
Страница 239: ...15 Mechanical Specifications ...
Страница 241: ...15 2 MECHANICAL SPECIFICATIONS s Figure 15 1 Package Dimensions Bottom View ...
Страница 252: ...16 Tools ...
Страница 260: ...16 8 TOOLS Figure 16 4 Generic MP System Layout for Debug Port Connection ...
Страница 264: ...17 OverDrive Processor Socket Specification ...
Страница 290: ...A Signals Reference ...
Страница 320: ...Index ...
Страница 328: ......