Altera Stratix GX Transceiver - Manual (Page 43)

Altera Corporation 2–25
January 2005 Stratix GX Transceiver User Guide
Stratix GX Analog Description
Figure 2–17. MegaWizard Plug-In Manager - ALTGXB (Page 5 of 7) - Receiver (3) Notes (1) – (3)
Notes to Figure 2–17 :
(1) Optional input signal that forces the CRU to lock to the reference clock. This disables the auto switch- over mode
that switches the CRU to lock-to-data mode. If both rx_locktorefclk and rx_locktodata are asserted, then
rx_locktodata
takes precedence.
(2) Optional input signal that forces the CRU to lock to the incoming data. If both rx_locktorefclk and
rx_locktodata
are asserted, rx_locktodata takes precedence.
(3) Optional output signal that indicates when the CRU is locked to the incoming data stream. The lock indication is
based on the following conditions:
a. The CRU PLL is within the prescribed PPM frequency threshold setting (125 PPM, 250 PPM, 500 PPM, 1,000 PPM)
of the CRU reference clock.
b. The reference clock and CRU PLL output are phase matched (~ phases are within 0.08 UI).