Package Trace Lengths For Pci Signals - Intel IXP28XX Manual

IXP28XX Network Processor
PCI
6.5
Note: It is typically not required to account for the package trace length for PCI interface signals.
Note: If the flight delay of the target PCB is not 180 ps/in then the ratio, (154/180), must be modified
Table 46.
Signal
PCI_ACK64_L
PCI_AD[0]
PCI_AD[1]
PCI_AD[10]
PCI_AD[11]
PCI_AD[12]
PCI_AD[13]
PCI_AD[14]
PCI_AD[15]
PCI_AD[16]
PCI_AD[17]
PCI_AD[18]
PCI_AD[19]
PCI_AD[2]
PCI_AD[20]
PCI_AD[21]
PCI_AD[22]
PCI_AD[23]
PCI_AD[24]
PCI_AD[25]
PCI_AD[26]
PCI_AD[27]
PCI_AD[28]
124
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Package Trace Lengths for PCI Signals

Table 46 provides package trace lengths for PCI signals.
The flight time on the package substrate is 154ps/in which differs from the flight delay of standard
FR4, typical 180ps/in. As a result the package routing lengths in
compensate for the difference in flight delay between the package and the PCB. For example
PCI_ACK64_L has a package length of 0.593 in, and the target PCB has a flight delay of 180ps/in.
In order to adjust the package length to match the PCB flight delay this length must be multiplied
by the ratio of 154/180 or the difference between the package and PCB flight delays. Therefore the
trace package routing length that must be accounted for on the PCB is 0.593*(154/180) or 0.507 in.
accordingly, i.e., the denominator would be changed to reflect the actual flight delay.
Package Trace Lengths for PCI Signals (Sheet 1 of 2)
Metric English
Units Units
(mm) (in)
15.052 0.593 PCI_AD[38]
6.118 0.241 PCI_AD[39]
7.934 0.312 PCI_AD[4]
11.996 0.472 PCI_AD[40]
16.187 0.637 PCI_AD[41]
2.379 0.094 PCI_AD[42]
10.843 0.427 PCI_AD[43]
13.881 0.546 PCI_AD[44]
13.628 0.537 PCI_AD[45]
8.055 0.317 PCI_AD[46]
11.044 0.435 PCI_AD[47]
3.802 0.150 PCI_AD[48]
7.593 0.299 PCI_AD[49]
14.995 0.590 PCI_AD[5]
12.79 0.504 PCI_AD[50]
10.251 0.404 PCI_AD[51]
10.299 0.405 PCI_AD[52]
5.299 0.209 PCI_AD[53]
1.845 0.073 PCI_AD[54]
17.686 0.696 PCI_AD[55]
7.434 0.293 PCI_AD[56]
2.48 0.098 PCI_AD[57]
12.666 0.499 PCI_AD[58]
Metric English
Signal Units Units
(mm) (in)
8.43 0.332
15.183 0.598
4.626 0.182
5.386 0.212
14.329 0.564
9.768 0.385
10.39 0.409
4.96 0.195
4.537 0.179
2.088 0.082
12.445 0.490
5.838 0.230
11.942 0.470
9.05 0.356
10.852 0.427
10.741 0.423
1.893 0.075
11.913 0.469
5.843 0.230
7.053 0.278
7.908 0.311
10.645 0.419
2.518 0.099
Table 46 must be adjusted to
Metric
Signal Units
(mm)
PCI_CBE_L[1] 3.597
PCI_CBE_L[2] 1.571
PCI_CBE_L[3] 9.587
PCI_CBE_L[4] 13.866
PCI_CBE_L[5] 3.349
PCI_CBE_L[6] 10.543
PCI_CBE_L[7] 6.818
PCI_CLK 5.22
PCI_DEVSEL_L 8.571
PCI_FRAME_L 4.673
PCI_GNT_L[0] 14.405
PCI_GNT_L[1] 13.908
PCI_IDSEL 11.147
PCI_INTA_L 12.348
PCI_INTB_L 7.397
PCI_IRDY_L 5.826
PCI_M66EN 1.72
PCI_PAR 13.373
PCI_PAR64 5.838
PCI_PERR_L 2.9
PCI_REQ_L[0] 3.644
PCI_REQ_L[1] 9.697
PCI_REQ64_L 1.72
Hardware Design Guide
English
Units
(in)
0.142
0.062
0.377
0.546
0.132
0.415
0.268
0.206
0.337
0.184
0.567
0.548
0.439
0.486
0.291
0.229
0.068
0.526
0.230
0.114
0.143
0.382
0.068