EP2S180F1020C4 Datasheet, PDF (747/768 Pages) Altera Corporation – Stratix II Device Handbook, Volume 1

High-Speed Board Layout Guidelines
Stratix^® II and Stratix GX devices provide programmable pre-emphasis to
compensate for variable lengths of transmission media. You can set the
pre-emphasis to between 5 and 25%, depending on the value of the
output differential voltage (V_OD) in the Stratix GX device. Table 11–2
shows the available Stratix GX programmable pre-emphasis settings.
Table 11–2. Programmable Pre-Emphasis with Stratix GX Devices
V_OD
400
480
600
800
960
1,000
1,200
1,400
1,440
1,500
1,600
5
420
504
630
840
1,008
1,050
1,260
1,470
1,512
1,575
-
Pre-emphasis Setting (%)
10
440
528
660
880
1,056
1,100
1,320
1,540
1,584
-
-
15
460
552
690
920
1,104
1,150
1,380
-
-
-
-
20
480
576
720
960
1,152
1,200
1,440
-
-
-
-
25
500
600
750
1,000
1,200
1,250
1,500
-
-
-
-
Routing
Schemes for
Minimizing
Crosstalk &
Maintaining
Signal Integrity
Crosstalk is the unwanted coupling of signals between parallel traces.
Proper routing and layer stack-up through microstrip and stripline
layouts can minimize crosstalk.
To reduce crosstalk in dual-stripline layouts that have two signal layers
next to each other, route all traces perpendicular, increase the distance
between the two signal layers, and minimize the distance between the
signal layer and the adjacent reference plane (see Figure 11–11).
Altera Corporation
May 2007
11–11
Stratix II Device Handbook, Volume 2