Altera Corporation
3–43
October 2007
Stratix II GX Device Handbook, Volume 2
Stratix II GX Dynamic Reconfiguration
To generate a MIF for the SONET/SDH protocol, set the SONET/SDH as
the main configuration in the ALT2GXB instance and GIGE as the
alternate protocol. This means SONET/SDH OC48 is achieved by the
main PLL and the alternate PLL/input reference clock configuration is
GIGE. Set the
Logical Reference index
option to
1
(since you have set the
logical reference index to
0
for the GIGE instance).
In the SONET/SDH MIF, the clock MUX select value is set to
0
to choose
the clock from the SONET/SDH TX PLL
Figure 3–21. MUX Setting - GIGE and SONET/SDH Mode, Logical Reference Clock Index = 1
When two modes are configured to switch from one to another using two
TX PLLs, you have to carefully select the logical reference index. In this
case, make sure the logical reference index that is set in one MIF is a
complement in the second MIF.
Steps
6
is discussed in
“Core Clocking” on page 3–45
.
CMU Block
TX Channel
Clocking
Block
TX Channel
RX Channel
0
1
TX High Speed Clocks
TX PLL 1
(SONET)
TX PLL 2
(GIGE)
pll_inclk
(77.76MHz)
pll_inclk_alt
(125 MHz)
625 MHz
1244.16 MHz
rx_cruclk_alt
(125 MHz)
rx_cruclk
(77.76 MHz)
MuxSelect=0
MuxSelect =0
0
1
Clock to CDR
local refclk