HC4GX15 Datasheet, PDF (132/668 Pages) Altera Corporation – HardCopy IV Device Handbook

8–22
Chapter 8: High-Speed Differential I/O Interfaces and DPA in HardCopy IV Devices
Guidelines for DPA-Disabled Differential Channels
Figure 8–22. Invalid Placement of DPA-Disabled Differential I/Os Due to Interleaving of Channels
Driven by the Corner and Center Left and Right PLLs
Corner
Left/Right PLL
Reference
CLK
DPA-disabled
Diff I/O
DPA-disabled
Diff I/O
DPA-disabled
Diff I/O
DPA-disabled
Diff I/O
DPA-disabled
Diff I/O
DPA-disabled
Diff I/O
DPA-disabled
Diff I/O
DPA-disabled
Diff I/O
DPA-disabled
Diff I/O
DPA-disabled
Diff I/O
Reference
CLK
Center
Left/Right PLL _-
Using Both Center Left/Right PLLs
You can use both center left and right PLLs simultaneously to drive DPA-disabled
channels on upper and lower differential banks, as shown in Figure 8–23. Unlike
DPA-enabled channels, the center left and right PLLs can drive cross-banks. For
example, the upper center left or right PLL can drive the lower differential bank while
the lower center left or right PLL is driving the upper differential bank and vice versa,
as shown in Figure 8–24.
HardCopy IV Device Handbook, Volume 1
© January 2010 Altera Corporation