IBM Intel Xeon E5620 49Y3773 User Manual
Product codes
49Y3773
Thermal Specifications
132
Intel
®
Xeon
®
Processor 5600 Series Datasheet Volume 1
frequencies and voltages. When the TCC is activated, the processor automatically
transitions to the new operating frequency. This transition occurs very rapidly (on the
order of 2 µs).
transitions to the new operating frequency. This transition occurs very rapidly (on the
order of 2 µs).
Once the new operating frequency is engaged, the processor will transition to the new
core operating voltage by issuing a new VID code to the voltage regulator. The voltage
regulator must support dynamic VID steps to support this method. During the voltage
change, it will be necessary to transition through multiple VID codes to reach the target
operating voltage. Each step will be one VID table entry (see
core operating voltage by issuing a new VID code to the voltage regulator. The voltage
regulator must support dynamic VID steps to support this method. During the voltage
change, it will be necessary to transition through multiple VID codes to reach the target
operating voltage. Each step will be one VID table entry (see
). The processor
continues to execute instructions during the voltage transition. Operation at the lower
voltages reduces the power consumption of the processor.
voltages reduces the power consumption of the processor.
A small amount of hysteresis has been included to prevent rapid active/inactive
transitions of the TCC when the processor temperature is near its maximum operating
temperature. Once the temperature has dropped below the maximum operating
temperature, and the hysteresis timer has expired, the operating frequency and
voltage transition back to the normal system operating point via the intermediate
VID/frequency points. Transition of the VID code will occur first, to insure proper
operation once the processor reaches its normal operating frequency. Refer to
transitions of the TCC when the processor temperature is near its maximum operating
temperature. Once the temperature has dropped below the maximum operating
temperature, and the hysteresis timer has expired, the operating frequency and
voltage transition back to the normal system operating point via the intermediate
VID/frequency points. Transition of the VID code will occur first, to insure proper
operation once the processor reaches its normal operating frequency. Refer to
for an illustration of this ordering.
7.2.2.2
Clock Modulation
Clock modulation is performed by alternately turning the clocks off and on at a duty
cycle specific to the processor (factory configured to 37.5% on and 62.5% off for TM1).
The period of the duty cycle is configured to 32 microseconds when the TCC is active.
Cycle times are independent of processor frequency. A small amount of hysteresis has
been included to prevent rapid active/inactive transitions of the TCC when the
processor temperature is near its maximum operating temperature. Once the
temperature has dropped below the maximum operating temperature, and the
hysteresis timer has expired, the TCC goes inactive and clock modulation ceases. Clock
cycle specific to the processor (factory configured to 37.5% on and 62.5% off for TM1).
The period of the duty cycle is configured to 32 microseconds when the TCC is active.
Cycle times are independent of processor frequency. A small amount of hysteresis has
been included to prevent rapid active/inactive transitions of the TCC when the
processor temperature is near its maximum operating temperature. Once the
temperature has dropped below the maximum operating temperature, and the
hysteresis timer has expired, the TCC goes inactive and clock modulation ceases. Clock
Figure 7-12. Frequency and Voltage Ordering
Temperature
f
MAX
f
1
f
2
VIDf
MAX
VID
Frequency
VIDf
2
VIDf
1
PROCHOT#
Time
Temperature
f
MAX
f
1
f
2
VIDf
MAX
VID
Frequency
VIDf
2
VIDf
1
PROCHOT#
Time