Altera Corporation
3–91
October 2007
Stratix II GX Device Handbook, Volume 2
Stratix II GX Dynamic Reconfiguration
Figure 3–40. Input Reference Clock Connections to the Transceiver Channel
Note to
Figure 3–40
:
(1)
These clocks can be provided from IQ lines, global clock networks, or dedicated local
refclks
.
1
Figure 3–40
shows the same input reference clocks connected to
both the TX PLLs and RX PLLs. If you enable the
Channel and
CMU PLL Reconfiguration
option for a full-duplex
configuration, you cannot provide separate reference clocks to
the TX PLLs and RX PLLs.
When you use the global clock line to provide input reference clocks, be
aware of the following restrictions and implications:
■
The hardware allows only one global clock input for the two TX PLLs
in a transceiver block (refer to
Figure 3–39
).
■
In a receiver-only channel configuration, the RX PLL of each channel
in a transceiver block can be clocked by an independent global clock
line. But, if you connect different clock input pins to the RX PLL in
each channel, you cannot reuse the MIFs between these two
channels. This constraint is explained further in
“Input Reference
Clock Requirements for Reusing MIFs” on page 3–94
.
■
Each global clock line consumes a local route input output (LRIO)
resource. Since each transceiver block has a fixed LRIO resource,
using the global clock line may restrict the number of clocks you can
provide to the transceiver channels in your design.
pll_inclk_rx_cruclk[4:0]
(1)
4
3
2
1
0
Clock Multiplier Unit
Full Duplex Transceiver Channel
TX CHANNEL
RX CHANNEL
TXPLL0
TXPLL1
clock
MUX
clock
MUX
Logical
TX PLL
Select
Local
Divider
D Analog
Logic
RX PLL
D Analog
Logic
clock
MUX
Содержание Stratix II GX
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