Cyclone II Architecture
PLLs
Cyclone II PLLs provide general-purpose clocking as well as support for
the following features:
■
■
■
■
■
■
■
■
■
■
Clock multiplication and division
Phase shifting
Programmable duty cycle
Up to three internal clock outputs
One dedicated external clock output
Clock outputs for differential I/O support
Manual clock switchover
Gated lock signal
Three different clock feedback modes
Control signals
Cyclone II devices contain either two or four PLLs. Table 2–3 shows the
PLLs available for each Cyclone II device.
Table 2–3. Cyclone II Device PLL Availability
Device
PLL1
PLL2
PLL3
PLL4
EP2C5
v
v
v
v
v
v
v
v
v
v
v
v
v
v
EP2C8
EP2C15
EP2C20
EP2C35
EP2C50
EP2C70
v
v
v
v
v
v
v
v
v
v
Altera Corporation
February 2007
2–25
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
