Altera Cyclone IV Device Handbook page 385

Chapter 2: Cyclone IV Reset Control and Power Down
Transceiver Reset Sequences
Transmitter Only Channel
This configuration contains only a transmitter channel. If you create a Transmitter
Only instance in the ALTGX MegaWizard Plug-In Manager, use the same reset
sequence shown in
Receiver Only Channel—Receiver CDR in Automatic Lock Mode
This configuration contains only a receiver channel. If you create a Receiver Only
instance in the ALTGX MegaWizard Plug-In Manager with the receiver CDR in
automatic lock mode, use the reset sequence shown in
Figure 2–6. Sample Reset Sequence of Receiver Only Channel—Receiver CDR in Automatic Lock Mode
Reset Signals
rx_analogreset
rx_digitalreset
Output Status Signals
busy (2)
rx_freqlocked
Notes to Figure 2–6:
(1) For t duration, refer to the
LTD_Auto
(2) 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
CDR automatic lock mode:
1. After power up, wait for the busy signal to be deasserted.
2. Keep the rx_digitalreset and rx_analogreset signals asserted during this time
period.
3. After the busy signal is deasserted, wait for another two parallel clock cycles, then
deassert the rx_analogreset signal.
4. Wait for the rx_freqlocked signal to go high.
5. When rx_freqlocked goes high (marker 3), from that point onwards, wait for
at least t
point, the receiver is ready to receive data.
September 2014 Altera Corporation
Figure 2–3 on page
2
Two parallel clock cycles
1
Cyclone IV Device Datasheet chapter.
Figure 2–6, perform the following reset procedure for the receiver in
, then de-assert the rx_digitalreset signal (marker 4). At this
LTD_Auto
2–7.
Figure 2–6.
4
3
t (1)
LTD_Auto
2–11
Cyclone IV Device Handbook,
Volume 2