IBM Intel Xeon E7430 44E4470 Data Sheet

Product codes
44E4470
Page of 136
Electrical Specifications
20
Intel® Xeon® Processor 7400 Series Datasheet
2.5
Reserved, Unused, or Test Signals
All Reserved signals must remain unconnected. Connection of these signals to V
CC
, V
TT
V
SS
, or to any other signal (including each other) can result in component malfunction 
or incompatibility with future processors. See 
 for a pin listing of the processor 
and the location of all Reserved signals.
For reliable operation, always connect unused inputs or bidirectional signals to an 
appropriate signal level. Unused active high inputs, should be connected through a 
resistor to ground (V
SS
). Unused outputs can be left unconnected; however, this may 
interfere with some TAP functions, complicate debug probing, and prevent boundary 
scan testing. A resistor must be used when tying bidirectional signals to power or 
ground. When tying any signal to power or ground, a resistor will also allow for system 
testability. Resistor values should be within ± 20% of the impedance of the baseboard 
trace for FSB signals, unless otherwise noticed in the appropriate platform design 
guidelines. For unused AGTL+ input or I/O signals, use pull-up resistors of the same 
value as the on-die termination resistors (R
TT
). For details see 
TAP, Asynchronous GTL+ inputs, and Asynchronous GTL+ outputs do not include on-die 
termination. Inputs and utilized outputs must be terminated on the baseboard. Unused 
outputs may be terminated on the baseboard or left unconnected. Note that leaving 
unused outputs unterminated may interfere with some TAP functions, complicate debug 
probing, and prevent boundary scan testing. Signal termination for these signal types 
is discussed in the appropriate platform design guidelines.
For each processor socket, connect the TESTIN1 and TESTIN2 signals together, then 
terminate the net with a 51 Ω resistor to V
TT
.
The TESTHI signals may use individual pull-up resistors or be grouped together as 
detailed below. 
• TESTHI[1:0] - can be grouped together with a single pull-up to V
TT
2.6
Front Side Bus Signal Groups
The FSB signals have been combined into groups by buffer type. AGTL+ input signals 
have differential input buffers, which use GTLREF_DATA_MID, GTLREF_DATA_END, 
GTLREF_ADD_MID, and GTLREF_ADD_END as reference levels. In this document, the 
term “AGTL+ Input” refers to the AGTL+ input group as well as the AGTL+ I/O group 
when receiving. Similarly, “AGTL+ Output” refers to the AGTL+ output group as well as 
the AGTL+ I/O group when driving. AGTL+ asynchronous outputs can become active 
anytime and include an active PMOS pull-up transistor to assist during the first clock of 
a low-to-high voltage transition. 
With the implementation of a source synchronous data bus comes the need to specify 
two sets of timing parameters. One set is for common clock signals whose timings are 
specified with respect to rising edge of BCLK0 (ADS#, HIT#, HITM#, etc.) and the 
second set is for the source synchronous signals which are relative to their respective 
strobe lines (data and address) as well as rising edge of BCLK0. Asynchronous signals 
are still present (A20M#, IGNNE#, etc.) and can become active at any time during the 
clock cycle. 
 identifies which signals are common clock, source synchronous 
and asynchronous.