HC4GX15 Datasheet, PDF (518/668 Pages) Altera Corporation – HardCopy IV Device Handbook

2–60
Chapter 2: HardCopy IV GX Dynamic Reconfiguration
PMA Controls Reconfiguration
Figure 2–25 shows the read transaction waveform. It assumes that the transmit V_OD
settings written in channels 1 and 2 prior to the read transaction are 3'b001 and 3'b010,
respectively.
Figure 2–25. Method 2—Read Transaction Waveform
reconfig_clk
read
busy
data_valid
rx_tx_duplex_sel [1:0] (1)
2’b00
2’b10
tx_vodctrl [5:0]
6’b000000
6’bXXXXXX
6’b010001
Note to Figure 2–25:
(1) Consider that you want to read from only the transmitter portion of all the channels.
1 Simultaneous write and read transactions are not allowed.
Use the Same Control Signal for All Channels Option Disabled
When the Use the same control signal for all channels option is disabled, the PMA
control ports for write transaction are separate for each channel.
PMA Control Ports Used in a Write Transaction:
■ tx_vodctrl is 3 bits per channel
■ tx_preemp_0t, tx_preemp_1t, and tx_preemp_2t are 5 bits per channel
■ rx_eqdcgain is 3 bits per channel
■ rx_eqctrl is 4 bits per channel
For example, if you have two channels, tx_vodctrl is 6 bits wide
(tx_vodctrl[2:0] corresponds to channel 1 and tx_vodctrl[5:3] corresponds
to channel 2).
HardCopy IV Device Handbook, Volume 3
© June 2009 Altera Corporation