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Resetting the Transceiver in CDR Manual Lock Mode
Follow this sequence to reset your transceiver when the CDR is in manual lock mode.
The numbers in the following figure correspond to the following numbered list, which guides you through
the steps to put the CDR in manual lock mode.
1. Make sure that the calibration is complete (
rx_cal_busy
is low) and the transceiver goes through the
initial reset sequence. The
rx_digitalreset
and
rx_analogreset
signals should be low. The
rx_is_lockedtoref
is a don't care and can be either high or low. The
rx_is_lockedtodata
and
rx_ready
signals should be high, indicating that the transceiver is out of reset. Alternatively, you
can start directly with the CDR in manual lock mode after the calibration is complete.
2. Assert the
rx_set_locktoref
signal high to switch the CDR to the lock-to-reference mode. The
rx_is_lockedtodata
status signal gets de-asserted. Assert the
rx_digitalreset
signal high
at the same time or after
rx_set_lockedtoref
is asserted if you use the user-controlled reset. When
the Transceiver PHY reset controller is used, the
rx_digitalreset
is automatically asserted.
3. After the
rx_digitalreset
signal gets asserted, the
rx_ready
status signal gets de-asserted.
4. Assert the
rx_set_locktodata
signal high after t
LTR_LTD_manual
to switch the CDR to the lock-to-
data mode. The
rx_is_lockedtodata
status signal gets asserted when it acquires lock to the data.
The
rx_is_lockedtoref
status signal can be a high or low and can be ignored.
5. Deassert the
rx_digitalreset
signal after t
LTD_Manual
.
6. After the
rx_digitalreset
signal is de-asserted, the
rx_ready
status signal gets asserted if you
are using the Transceiver PHY Reset Controller, indicating that the receiver is now ready to receive data
with the CDR in manual mode.
Figure 3-9: Reset Sequence Timing Diagram for Transceiver when CDR is in Manual Lock Mode
rx_digitalreset
rx_set_locktoref
rx_set_locktodata
rx_is_lockedtoref
rx_is_lockedtodata
rx_analogreset
rx_ready
Status Signals
Control Signals
t
LTD_Manual
min 4 μs
1
2
2
4
5
6
3
t
LTR_LTD_manual
min 15 μs
1
1
1
1
2
4
Resetting the Transceiver During Dynamic Reconfiguration
Reset is required for transceiver during dynamic reconfiguration except in the PMA Analog Control
Reconfiguration mode.
In general, follow these guidelines when dynamically reconfiguring the transceiver:
1. Hold the targeted channel and PLL in the reset state before dynamic reconfiguration starts.
Altera Corporation
Transceiver Reset Control in Cyclone V Devices
3-13
Resetting the Transceiver in CDR Manual Lock Mode
CV-53003
2013.05.06