EP2S180F1020C4 Datasheet, PDF (279/768 Pages) Altera Corporation – Stratix II Device Handbook, Volume 1

PLLs in Stratix II and Stratix II GX Devices
Table 1–7. Stratix II and Stratix II GX Enhanced PLL Pins (Part 3 of 3) Note (1)
Pin
VCC_PLL12_OUT
Description
External clock output V_CCIO power for PLL12_OUT0p, PLL12_OUT0n,
PLL12_OUT1p, PLL12_OUT1n and PLL12_OUT2p, PLL12_OUT2n outputs
from PLL 12.
Note to Table 1–7:
(1) The negative leg pins (CLKn, PLL_FBn, and PLL_OUTn) are only required with differential signaling.
Fast PLLs
Stratix II devices contain up to eight fast PLLs and Stratix II GX devices
contain up to four fast PLLs. Fast PLLs have high-speed differential I/O
interface capability along with general-purpose features.
Fast PLL Hardware Overview
Figure 1–7 shows a diagram of the fast PLL.
Figure 1–7. Stratix II and Stratix II GX Fast PLL Block Diagram
Global or
regional clock (2)
Clock (1)
Switchover
Circuitry
Clock
4
÷n
Input
Global or
regional clock (2)
Shaded Portions of the
PLL are Reconfigurable
Phase
Frequency
Detector
PFD
Charge
Pump
VCO Phase Selection
Selectable at each PLL
Output Port
Post-Scale
Counters
Loop
Filter
VCO
(5) ₈
÷k
÷m
÷c0
÷c1
÷c2
4
÷c3
diffioclk0 (3)
loaden0 (4)
diffioclk1 (3)
loaden1 (4)
4
Global clocks
8
Regional clocks
8
to DPA block
Notes to Figure 1–7:
(1) Stratix II and Stratix II GX fast PLLs only support manual clock switchover.
(2) The global or regional clock input can be driven by an output from another PLL, a pin-driven dedicated global or
regional clock, or through a clock control block provided the clock control block is fed by an output from another
PLL or a pin-driven dedicated global or regional clock. An internally generated global signal cannot drive the PLL.
(3) In high-speed differential I/O support mode, this high-speed PLL clock feeds the SERDES. Stratix II devices only
support one rate of data transfer per fast PLL in high-speed differential I/O support mode.
(4) This signal is a high-speed differential I/O support SERDES control signal.
(5) If the design enables this ÷2 counter, then the device can use a VCO frequency range of 150 to 520 MHz.
Altera Corporation
July 2009
1–15
Stratix II Device Handbook, Volume 2