Altera Corporation
3–75
October 2007
Stratix II GX Device Handbook, Volume 2
Stratix II GX Dynamic Reconfiguration
4.
Select the
Channel internals
and
Use alternate reference clock
options. Selecting these options enable the second PLL for the
SONET/SDH OC48 mode. A second PLL is needed because of the
difference in the required input clock frequency and data rate
between the GIGE and SONET/SDH OC48 modes (refer to rows 6
and 7 in
Table 3–5
).
5.
Set the
What is the protocol to be reconfigured?
option to
SONET/SDH
.
6.
Set the
sub protocol
option to
OC48
(see
Figure 3–31
).
7.
Select the
input clock frequency
and
alternate transmitter PLL
bandwidth mode
options based on the requirements. The allowed
reference clock input frequencies for SONET/SDH OC48 are
specified in row 7 of
Table 3–5
.
8.
For the
What is the logical reference index?
option, select
1
or
0
.
The Quartus II software uses the logical reference index to select the
PLL clock outputs for the transmit and receive channels when
configured to SONET/SDH OC48 protocol. The MUX values
selected for the GIGE and SONET/SDH OC48 modes should be
different.
1
For example, if you select
1
for the
What is the logical reference
index?
option for the SONET/SDH OC48 mode, you should
select
0
for GIGE mode. If you select the same values for the two
modes, the transceiver behavior after reconfiguration becomes
unpredictable.
9.
Select the
Channel interface
option. Selecting
Channel interface
creates the data interface signals
tx_datainfull
and
rx_dataoutfull
that are comprised of control and data signals.
This selection is required because of the differences in the PLD
interface width between the GIGE and SONET/SDH modes (row 1
in
Table 3–5
). The description of individual bits of
tx_datainfull
and
rx_datainfull
are provided in
“Channel Interface” on
page 3–53
.
10. In the
Reconfig2
tab, under the
How should the receivers be
clocked?
option, check the
Use the respective channel core clocks
option. Selecting this option creates the
rx_clkout
port. Select this
option because of the clocking differences between the two modes
(row 5 of
Table 3–5
). Therefore, the PLD logic can clock the receive
output of the ALT2GXB with
rx_clkout
for SONET/SDH mode
and
tx_clkout
for the GIGE mode.