2–144
Altera Corporation
Stratix II GX Device Handbook, Volume 2
October 2007
Multiple Protocols and Data Rates in a Transceiver Block
Figure 2–109
is the resultant transceiver block configuration after
combining the above instances. Since the two TXPLLs primary data rates
can be derived from the same reference clock frequency, one reference
clock input is needed. If the reference clock frequency differs, or if the
primary data rates differ (for example, 2.488 Gbps instead of 2 Gbps), two
reference clocks will be needed.
1
If the reference clock is driven from the PLD, only one
connection exists for each transceiver block. Both TXPLLs in a
transceiver block cannot be driven from separate PLD clock
pins. If the reference clock frequencies are the same, it is possible
to drive both TXPLLs in a transceiver block from a single PLD
clock pin (or the dedicated
REFCLK
pin).
Figure 2–109. Resultant Transceiver Block Configuration with Two TXPLLs
Transceiver Block
Ch 1
Data rate: 4 Gbps
TX Loc Div: / 1
Ch 0
Data rate: 4 Gbps
TX Loc Div: / 1
TXPLL 0
Primary Data
rate : 4 Gbps
Ch 3
Data rate : 1 Gbps
TX Loc Div : / 2
Ch 2
Data rate: 2 Gbps
TX Loc Div: / 1
TXPLL 1
Primary Data
rate: 2 Gbps