HC4GX15 Datasheet, PDF (512/668 Pages) Altera Corporation – HardCopy IV Device Handbook

2–54
Chapter 2: HardCopy IV GX Dynamic Reconfiguration
PMA Controls Reconfiguration
Method 1
Using Method 1, you can dynamically reconfigure the PMA controls of a transceiver
channel by using the logical_channel_address port without affecting the
remaining active channels. You can enable the logical_channel_address_port
port by selecting the Use 'logical_channel_address' port for Analog controls
reconfiguration option in the Analog controls screen, as shown in Figure 2–19 on
page 2–51. This method is applicable only for a design where the dynamic
reconfiguration controller controls more than one channel.
You can additionally reconfigure either the receiver portion, transmitter portion, or
both the receiver and transmitter portions of the transceiver channel by setting the
corresponding value on the rx_tx_duplex_sel[1:0] input port.
Connecting the PMA Control Ports
When using Method 1, the selected PMA control ports remain fixed in width,
regardless of the number of channels controlled by the ALTGX_RECONFIG instance:
■ tx_vodctrl and tx_vodctrl_out are fixed to 3 bits
■ tx_preemp_0t, tx_preemp_1t, tx_preemp_2t, tx_preemp_0t_out,
tx_preemp_1t_out and tx_preemp_2t_out are fixed to 5 bits
■ rx_eqdcgain and rx_eqdcgain_out are fixed to 3 bits
■ rx_eqctrl and rx_eqctrl_out are fixed to 4 bits
Write Transaction
Set the selected PMA control ports to the desired settings (for example, tx_vodctrl
= 3'b000). Set the input port logical_channel_address to the logical channel
address of the transceiver channel whose PMA controls you want to reconfigure. Set
the rx_tx_duplex_sel[1:0] port to 2'b10 so that only the transmit PMA controls
are written to the transceiver channel. Ensure that the busy signal is low before you
start a write transaction. Assert the write_all signal for one reconfig_clk clock
cycle. This initiates the write transaction.
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 2–21 shows the write
transaction waveform.
HardCopy IV Device Handbook, Volume 3
© June 2009 Altera Corporation