Справочник Пользователя для AMD Phenom 8450 Triple-Core HD8450WCGHBOX
Модели
HD8450WCGHBOX
32
Product Errata
41322
Rev. 3.16 February 2008
Revision Guide for AMD Family 10h Processors
274 IDDIO Specification Exceeded During Power-Up Sequencing
Description
Processor current consumption may exceed the IDDIO maximum specified for C0/S0 operation
during power-up sequencing.
during power-up sequencing.
Potential Effect on System
None expected if the VDDIO voltage regulator is sourced by a RUN (running) plane from the power
supply during power-up sequencing. Otherwise, during power-up sequencing the VDDIO voltage
regulator may shut down if IDDIO exceeds the platform budget or the power supply may shut down if
the SUS (suspend) rail current capacity is exceeded.
supply during power-up sequencing. Otherwise, during power-up sequencing the VDDIO voltage
regulator may shut down if IDDIO exceeds the platform budget or the power supply may shut down if
the SUS (suspend) rail current capacity is exceeded.
Suggested Workaround
Three options exist to ensure the VDDIO voltage regulator is sourced with sufficient current during
processor power-up sequencing:
processor power-up sequencing:
1. Enable the VDDIO voltage regulator after POWER_GOOD is asserted from the high-current
(RUN) source rail.
2. Provide a path for a high-current (RUN) rail to source current to the VDDIO voltage regulator
prior to POWER_GOOD assertion from the high-current (RUN) rail. This solution assumes the
high-current (RUN) rail is enabled early enough relative to enabling the VDDIO voltage
regulator.
high-current (RUN) rail is enabled early enough relative to enabling the VDDIO voltage
regulator.
3. Choose a power supply with increased capacity for the rail sourcing the VDDIO voltage regulator
during power-up sequencing. The capacity required is system specific and should allocate 7 amps
per processor in the power budget. The following is an example of a supply current capacity
calculation assuming a 5 V suspend rail and 3 W rest of system power for a single-processor
system. Other platform-specific factors such as power supply or regulator efficiencies should also
be considered.
per processor in the power budget. The following is an example of a supply current capacity
calculation assuming a 5 V suspend rail and 3 W rest of system power for a single-processor
system. Other platform-specific factors such as power supply or regulator efficiencies should also
be considered.
•
Rest of system (non-processor) power = 3 W
•
Processor power = 7 A/processor * 1 processor * 1.8 V = 12.6 W
•
Source rail capacity = (rest of system power + processor power) / source rail voltage; (3 W +
12.6 W) / 5 V = 3.12 A
12.6 W) / 5 V = 3.12 A
Fix Planned
Yes