Altera Corporation
3–15
October 2007
Stratix II GX Device Handbook, Volume 2
Stratix II GX Dynamic Reconfiguration
(eight channels) by dynamic reconfiguration. This is needed because
based on this setting, the Quartus II software chooses the bus width
of the signal
reconfig_fromgxb
in addition to the width of the
analog control signals. In this case, the design needs 3-bits wide
signals so the controller can control a total of three transceiver blocks
(five channels in two transceiver blocks and three channels into one
transceiver block).
To make it simple, choose the channel number based on a rounded-up
channel number to the nearest transceiver block multiple. In this case, it
is eight channels required and since no merging is allowed, eight
channels require three transceiver blocks. The three transceiver blocks
round up to a transceiver block multiple channel number of 12 (3 × 4 =
12). Refer to the “
1. What is the number of channels controlled by the
controller?
” option in
“Dynamic Reconfiguration Controller Interface”
on page 3–5
for more information about this setting.
■
Select the necessary analog control signals to write in and read out
for V
OD
and equalization from all the options available in the
MegaWizard. Also note the analog control signal widths are for 12
channels since the above channel setting is 12. Control signals for
unused channels 5 to 7 and channel 11 can be tied to logic low
(zero/ground). In this design scenario, the V
OD
signal
(
tx_vodctrl
) width is 36 bits (12 channel ×
tx_vodctrl[2:0]
=
tx_vodctrl[35:0]
). Tie
tx_vodctrl[35:33]
and
tx_vodctrl[23:15]
to ground. Use similar methods for the
equalization setting.
ALT2GXB Instances and ALT2GXB_RECONFIG Instance
Connections:
■
Connect the
reconfig_fromgxb
signal from the ALT2GXB
instance to the same signal in the ALT2GXB_RECONFIG instance.
The lowest starting channel number transceiver block is connected to
the lowest significant bit and so on. In this case, the configuration
instance with five channels of the ALT2GXB instance has a starting
channel of zero, which has the signal
reconfig_fromgxb[1:0]
which should be connected to
reconfig_fromgxb[1:0]
of the
ALT2GXB_RECONFIG instance. The other three channel instances
of ALT2GXB, with a starting channel of eight, has the signal
reconfig_fromgxb
which should be connected to
ALT2GXB_RECONFIG
reconfig_fromgxb[2]
. Refer to
Figure 3–3
for more information.
■
Connect the
reconfig_togxb
signal from the
ALT2GXB_RECONFIG instance to the same signal on the ALT2GXB
instance.
Содержание Stratix II GX
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