EP4CE30F29C7N Datasheet, PDF (386/488 Pages) Altera Corporation – Cyclone IV Device Handbook, Volume 1

2–12
Chapter 2: Cyclone IV Reset Control and Power Down
Transceiver Reset Sequences
Receiver Only Channel—Receiver CDR in Manual Lock Mode
This configuration contains only a receiver channel. If you create a Receiver Only
instance in the ALTGX MegaWizard Plug-In Manager with receiver CDR in manual
lock mode, use the reset sequence shown in Figure 2–7.
Figure 2–7. Sample Reset Sequence of Receiver Only Channel—Receiver CDR in Manual Lock Mode
Reset Signals
2
rx_analogreset
4
rx_digitalreset
CDR Control Signals
rx_locktorefclk
rx_locktodata
t_{LTR_LTD_Manual} (1)
t_{LTD_Manual} (2)
3
3
Output Status Signals
busy (3)
Two parallel clock cycles
1
rx_pll_locked
Notes to Figure 2–7:
(1) For t_{LTR_LTD_Manual} duration, refer to the Cyclone IV Device Datasheet chapter.
(2) For t_{LTD_Manual} duration, refer to the Cyclone IV Device Datasheet chapter.
(3) The busy signal is asserted and deasserted only during initial power up when offset cancellation occurs. In subsequent reset sequences, the busy
signal is asserted and deasserted only if there is a read or write operation to the ALTGX_RECONFIG megafunction.
As shown in Figure 2–7, perform the following reset procedure for the receiver CDR
in manual lock mode:
1. After power up, wait for the busy signal to be asserted.
2. Keep the rx_digitalreset and rx_locktorefclk signals asserted and the
rx_locktodata signal deasserted during this time period.
3. After deassertion of the busy signal (marker 1), wait for two parallel clock cycles to
deassert the rx_analogreset signal (marker 2). After rx_analogreset deassert,
rx_pll_locked will assert.
4. Wait for at least t_{LTR_LTD_Manual}, then deassert the rx_locktorefclk signal. At the
same time, assert the rx_locktodata signal (marker 3).
5. Deassert rx_digitalreset at least t_{LTD_Manual} (the time between markers 3
and 4) after asserting the rx_locktodata signal. At this point, the
receiver is ready to receive data.
Cyclone IV Device Handbook,
Volume 2
May 2013 Altera Corporation