Datasheet

Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 v2 Product Families 51
Datasheet Volume One of Two
Interfaces
2.5.2.6.13 Package Power SKU Unit Read
This feature enables the PECI host to read the units of time, energy and power used in
the processor and DRAM power control registers for calculating power and timing
parameters. In Figure 2-27, the default value of the power unit field [3:0] is 0011b,
energy unit [12:8] is 10000b and the time unit [19:16] is 1010b. Actual unit values are
calculated as shown in Table 2-9.
2.5.2.6.14 Package Power SKU Read
This read allows the PECI host to access the minimum, Thermal Design Power and
maximum power settings for the processor package SKU. It also returns the maximum
time interval or window over which the power can be sustained. If the power limiting
entity specifies a power limit value outside of the range specified through these
settings, power regulation cannot be guaranteed. Since this data is 64 bits wide, PECI
facilitates access to this register by allowing two requests to read the lower 32 bits and
upper 32 bits separately as shown in Table 2-8. Power units for this read are
determined as per the Package Power SKU Unit settings described in
Section 2.5.2.6.13.
‘Package Power SKU data’ is programmed by the PCU firmware during boot time based
on SKU dependent power-on default values set during manufacturing. The TDP
package power specified through bits [14:0] in Figure 2-28 is the maximum value of
the ‘Power Limit1’ field in Section 2.5.2.6.26 while the maximum package power in bits
[46:32] is the maximum value of the ‘Power Limit2’ field.
The minimum package power in bits [30:16] is applicable to both the ‘Power Limit1’ &
‘Power Limit2’ fields and corresponds to a mode when all the cores are operational and
in their lowest frequency mode. Attempts to program the power limit below the
minimum power value may not be effective since BIOS/OS, and not the PCU, controls
disabling of cores and core activity.
Figure 2-26. Machine Check Status
MCA Error Source Log
Reserved
28
0
MCERRIERRCATERR
293031
Figure 2-27. Package Power SKU Unit Data
Table 2-9. Power Control Register Unit Calculations
Unit Field Value Calculation Default Value
Time 1s / 2
TIME UNIT
1s / 2
10
= 976 µs
Energy 1J / 2
ENERGY UNIT
1J / 2
16
= 15.3 µJ
Power 1W / 2
POWER UNIT
1W / 2
3
= 1/8 W
Reserved
2031
Time Unit
19
Reserved
16 15
Energy Unit
12 8
Reserved Power Unit
13 7 4 3 0