Electrical Specifications
The processor core frequency is configured during reset by using values stored
internally during manufacturing. The stored value sets the highest bus fraction at which
the particular processor can operate. If lower speeds are desired, the appropriate ratio
can be configured via the IA32_FLEX_BRVID_SEL MSR. For details of operation at core
frequencies lower than the maximum rated processor speed, refer to the IA-32 Intel®
Architecture Software Developer’s Manual, Volume 3A &3B.
Clock multiplying within the processor is provided by the internal phase locked loop
(PLL), which requires a constant frequency BCLK[1:0] input, with exceptions for spread
spectrum clocking. The Dual-Core Intel Xeon Processor 5000 series utilize differential
clocks. Table 2-1 contains processor core frequency to FSB multipliers and their
corresponding core frequencies.
Table 2-1.
Core Frequency to FSB Multiplier Configuration
Core Frequency to FSB
Multiplier
Core Frequency with
166 MHz FSB Clock
Processor Number
Notes
1/16
1/18
2.67 GHz
3 GHz
5030
5050
1, 2, 3, 4
1, 2, 3, 4
Core Frequency to FSB
Multiplier
Core Frequency with
266 MHz FSB Clock
Notes
1/12
1/12
1/14
3.20 GHz
3.20 GHz
3.73 GHz
5063
5060
5080
1, 2, 3, 4
1, 2, 3, 5
1, 2, 3
Notes:
1.
2.
3.
Individual processors operate only at or below the frequency marked on the package.
Listed frequencies are not necessarily committed production frequencies.
For valid processor core frequencies, refer to the Dual-Core Intel Xeon Processor 5000 series
Specification Update.
Mid-voltage (MV) processors only.
®
®
4.
5.
The lowest bus ratio supported by the Dual-Core Intel Xeon Processor 5000 series is 1/12.
2.4.1
Front Side Bus Frequency Select Signals (BSEL[2:0])
Upon power up, the FSB frequency is set to the maximum supported by the individual
processor. BSEL[2:0] are open drain outputs which must be pulled up to VTT, and are
used to select the FSB frequency. Please refer to Table 2-12 for DC specifications.
Table 2-2 defines the possible combinations of the signals and the frequency associated
with each combination. The frequency is determined by the processor(s), chipset, and
clock synthesizer. All FSB agents must operate at the same core and FSB frequency.
See the appropriate platform design guidelines for further details.
Table 2-2.
BSEL[2:0] Frequency Table
BSEL2
BSEL1
BSEL0
Bus Clock Frequency
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
266.67 MHz
Reserved
Reserved
166.67 MHz
Reserved
Reserved
Reserved
Reserved
Dual-Core Intel® Xeon® Processor 5000 Series Datasheet
17
INTEL [ INTEL ]
