EP4CE30F29C7N Datasheet, PDF (415/488 Pages) Altera Corporation – Cyclone IV Device Handbook, Volume 1

Chapter 3: Cyclone IV Dynamic Reconfiguration
Dynamic Reconfiguration Modes
3–17
PMA Control Ports Used in a Read Transaction
■ tx_vodctrl_out is 3 bits per channel
■ tx_preemp_out is 5 bits per channel
■ rx_eqdcgain_out is 2 bits per channel
■ rx_eqctrl_out is 4 bits per channel
For example, assume the number of channels controlled by the dynamic
reconfiguration controller is two, tx_vodctrl_out is 6 bits wide.
Write Transaction
The value you set at the selected PMA control ports is written to all the transceiver
channels connected to the ALTGX_RECONFIG instance.
For example, assume you have enabled tx_vodctrl in the ALTGX_RECONFIG
MegaWizard Plug-In Manager to reconfigure the V_OD of the transceiver channels. To
complete a write transaction to reconfigure the V_OD, perform the following steps:
1. Before you initiate a write transaction, set the selected PMA control ports to the
desired settings (for example, tx_vodctrl = 3'b001).
2. Set the rx_tx_duplex_sel port to 2'b10 so that only the transmit PMA controls are
written to the transceiver channel.
3. Ensure that the busy signal is low before you start a write transaction.
4. Assert the write_all signal for one reconfig_clk clock cycle. This initiates the
write transaction.
5. The busy output status signal is asserted high to indicate that the dynamic
reconfiguration controller is busy writing the PMA control values. When the write
transaction has completed, the busy signal goes low.
Figure 3–6 shows the write transaction for Method 2.
Figure 3–6. Write Transaction Waveform—Use the same control signal for all the channels Option
reconfig_clk
write_all
rx_tx_duplex_sel [1:0] (1)
busy
2'b00
2'b10
tx_vodctrl [2:0]
3'b111
3'b001
Note to Figure 3–6:
(1) In this waveform example, you want to write to only the transmitter portion of the channel.
November 2011 Altera Corporation
Cyclone IV Device Handbook,
Volume 2