Design Considerations; Figure 33. Processor Topology; Table 12. Processor Package Lengths - Intel Pentium 4 Design Manual

System Bus Routing
Common Clock
Common clock signals should be routed to a minimum pin to pin motherboard length of 6 inches
and a maximum motherboard length of 10 inches.

Figure 33. Processor Topology

5.3.1.2

Design Considerations

Intel has found that the following recommendations aid in the routing of the processor, given the
example stack-up shown in Figure 9.
•
Line width is 7.0 mil.
•
Trace to trace spacing is 13.0 mil (except in component breakout where spacing is
constrained where 5 mil spacing is acceptable)

Table 12. Processor Package Lengths

Net Name
Address Group 0
ADSTB#[0]
A#[03]
A#[04]
A#[05]
A#[06]
A#[07]
A#[08]
A#[09]
A#[10]
A#[11]
A#[12]
A#[13]
A#[14]
66
Processor
Pad
Package trace
Motherboard PCB trace
® ®
Intel Pentium
478-pin Package Length (inches)
0.201
0.344
0.249
0.139
0.394
0.279
0.130
0.369
0.323
0.230
0.382
0.396
0.335
® ®
Intel Pentium 4 Processor / Intel
Length L1
4 Processor in Intel
512-KB L2 Cache on 0.13 Micron
Process Package Length (inches)
®
850 Chipset Family Platform Design Guide
850 MCH
Pad
® ®
Pentium 4 Processor with
0.219
0.393
0.281
0.170
0.436
0.330
0.157
0.374
0.330
0.261
0.407
0.420
0.362
R