EP4SE360F35I4 Datasheet, PDF (144/432 Pages) Altera Corporation – This section provides a complete overview of all features relating to the Stratix IV device family, which is the most architecturlly advanced

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Chapter 5: Clock Networks and PLLs in Stratix IV Devices
PLLs in Stratix IV Devices
Clock Feedback Modes
Stratix IV PLLs support up to six different clock feedback modes. Each mode allows
clock multiplication and division, phase shifting, and programmable duty cycle.
Table 5–9 lists the clock feedback modes supported by the Stratix IV device PLLs.
Table 5–9. Clock Feedback Mode Availability
Clock Feedback Mode
Availability
Top and Bottom PLLs
Left and Right PLLs
Source-synchronous
Yes
Yes
No-compensation
Yes
Yes
Normal
Yes
Yes
Zero-delay buffer (ZDB)
External feedback ⁽¹⁾
Yes
Yes
Yes
Yes ⁽²⁾
LVDS compensation
No
Yes
Notes to Table 5–9:
(1) The high-bandwidth PLL setting is not supported in external feedback mode.
(2) External feedback mode is supported for single-ended inputs and outputs only on the left and right PLLs.
1 The input and output delays are fully compensated by a PLL only when using the
dedicated clock input pins associated with a given PLL as the clock source. For
example, when using PLL_T1 in normal mode, the clock delays from the input pin to
the PLL clock output-to-destination register are fully compensated, provided the
clock input pin is one of the following two pins: CLK14 and CLK15. Compensated pins
are only in the same I/O bank as the PLL. When an RCLK or GCLK network drives
the PLL, the input and output delays may not be fully compensated in the Quartus II
software. Another example is when you configure PLL_T2 in zero-delay buffer mode
and the PLL input is driven by a dedicated clock input pin, a fully compensated clock
path results in zero-delay between the clock input and one of the output clocks from
the PLL. If the PLL input is instead fed by a non-dedicated input (using the GCLK
network), the output clock may not be perfectly aligned with the input clock.
Stratix IV Device Handbook
Volume 1
September 2012 Altera Corporation