Altera Stratix GX Transceiver - Manual (Page 248)

9–22 Altera Corporation
Stratix GX Transceiver User Guide January 2005
Recommended Resets
Figure 9–9. Receiver Reset Sequence Waveform
Design Example 1
This design example shows inclk as the transmit PLL input reference
clock and the transmit parallel clock, rx_cruclk as the receive CRU
input reference clock, and rx_coreclk as the receive parallel clock.
This design example has following constraints:
■ If your design requirements are different from the examples, use the
flow charts and waveforms for each configuration as design
guidelines.
■ The design example requires a reset controller that generates a
sync_reset
(synchronous reset) for the entire system.
■ The design example has an async_reset (a power down in GXB
terms) and digital resets for transmit and receive. All user input
digital resets must be at least four cycles long.
■ This design example does not cover all the digital reset scenarios in
a system that resets the digital logic of the GXB.
■ In this example, whenever the rx_freqlocked signal toggles the
rxdigitalreset
, the receiver’s digital circuit is reset. However,
you can make changes to the design to avoid this if, for example, you
want to debug your design without the core being reset.
■ If you plan to use REFCLKB pins in your design, see Appendix C,
REFCLKB Pin Constraints for information about the effects of analog
resets (pll_arest, rx_analogreset).
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Stable Recovered Clock
1 2
3
4
rx_analogreset
rx_digitalreset
rx_freqlocked
Output Status
Reset Signals
Trx_freqlock2phaselock