Intel X5460 AT80574KJ087N Data Sheet

Product codes
AT80574KJ087N
Page of 118
Quad-Core Intel® Xeon® Processor 5400 Series Electrical Specifications
24
2.8
CMOS Asynchronous and Open Drain 
Asynchronous Signals
Legacy input signals such as A20M#, IGNNE#, INIT#, SMI#, and STPCLK# utilize 
CMOS input buffers. Legacy output signals such as FERR#/PBE#, IERR#, PROCHOT#, 
and THERMTRIP# utilize open drain output buffers. All of the CMOS and Open Drain 
signals are required to be asserted/deasserted for at least eight BCLKs in order for the 
processor to recognize the proper signal state. See 
 for the DC 
specifications. Se
 for additional timing requirements for entering and 
leaving the low power states.
2.9
Test Access Port (TAP) Connection
Due to the voltage levels supported by other components in the Test Access Port (TAP) 
logic, it is recommended that the processor(s) be first in the TAP chain followed by any 
other components within the system. A translation buffer should be used to connect to 
the rest of the chain unless one of the other components is capable of accepting an 
input of the appropriate voltage. Similar considerations must be made for TCK, TDO, 
TMS, and TRST#. Two copies of each signal may be required with each driving a 
different voltage level. 
2.10
Platform Environmental Control Interface (PECI) 
DC Specifications
PECI is an Intel proprietary one-wire interface that provides a communication channel 
between Intel processors and chipset components to external thermal monitoring 
devices. The Quad-Core Intel® Xeon® Processor 5400 Series contains Digital Thermal 
Sensor (DTS) sprinkled both inside and outside the cores in a die. These sensors are 
implemented as analog-to-digital converters calibrated at the factory for reasonable 
accuracy to provide a digital representation of relative processor temperature. PECI 
provides an interface to relay the highest DTS temperature within a die to external 
devices for thermal/fan speed control. More detailed information may be found in the 
Platform Environment Control Interface (PECI) Specification.
2.10.1
DC Characteristics
The PECI interface operates at a nominal voltage set by V
TT
. The set of DC electrical 
specifications shown in 
 is used with devices normally operating from a V
TT
 
interface supply. V
TT
 nominal levels will vary between processor families. All PECI 
devices will operate at the V
TT
 level determined by the processor installed in the 
system. For specific nominal V
TT
 levels, refer to the appropriate processor EMTS.