3. Deassert tx_digitalreset after a minimum duration of ttx_digitalreset, and after all the gating conditions
are removed:
pll_powerdown is deasserted
pll_locked is deasserted
Figure 3-6: Reset Sequence Timing Diagram for Transmitter using the User-Coded Reset Controller
during Device Operation
pll_locked
tx_digitalreset
tx_analogreset
pll_powerdown
t
pll_powerdown min 1 μs
t
tx_digitalreset min 20ns
1
2
3
1
t
pll_lock max 10 μs
tx_cal_busy
mgmt_rst_reset
1
Resetting the Receiver with the User-Coded Reset Controller during Device Power-Up
Configuration
Follow this reset sequence to ensure a reliable receiver initialization after the initial power-up.
The numbers in the following figure correspond to the following numbered list, which guides you through
the receiver reset sequence during device power-up.
1. Assert mgmt_rst_reset at power-up to start the calibration IPs. Hold mgmt_rst_reset active
for a minimum of two mgmt_clk_clock cycles. Hold rx_analogreset and rx_digitalreset
active at power-up to hold the receiver in reset. You can deassert them after all the gating conditions are
removed.
2. After the receiver calibration completes, the rx_cal_busy status is de-asserted.
3. Deassert rx_analogreset after a minimum duration of trx_analogreset after rx_cal_busy is deasserted.
4. rx_is_lockedtodata is a status signal from the receiver CDR indicating that the CDR is in the lock
to data (LTD) mode. Ensure rx_is_lockedtodata is asserted and stays asserted for a minimum
duration of tLTD before deasserting rx_digitalreset. If rx_is_lockedtodata is asserted and
toggles, you must wait another additional tLTD duration before deasserting rx_digitalreset.
5. Deassert rx_digitalreset after a minimum duration of tLTD after rx_is_lockedtodata stays
asserted. Ensure rx_analogreset and rx_cal_busy are deasserted before deasserting
rx_digitalreset
.
The receiver is now out of reset and ready for operation.
rx_is_lockedtodata
might toggle when there is no data at the receiver
input.
Note:
Altera Corporation
Transceiver Reset Control in Cyclone V Devices
3-9
Resetting the Receiver with the User-Coded Reset Controller during Device Power-Up Configuration
CV-53003
2013.05.06