Altera Corporation
3–1
October 2007
3. Stratix II GX Dynamic
Reconfiguration
Introduction
The Stratix
®
II GX gigabit transceiver block gives you a simplified means
to dynamically reconfigure:
■
Transmit and receive analog settings
■
Transmit data rate in the multiples of 1, 2, and 4
■
One channel at a time
■
Channel and clock multiplier unit (CMU) PLL
■
CMU PLL only
Typically, to achieve the intended bit error rate (BER) for a system, you
will take advantage of the multiple analog settings provided in the
Stratix II GX device. Being able to change the analog settings is a
powerful tool that you can use during link and system debug.
The following analog settings can be dynamically changed:
■
Pre-emphasis settings
■
Equalization settings
■
DC gain settings
■
Voltage output differential (V
OD
) settings
In addition to allowing you to change the equalization settings during
runtime, the dynamic reconfiguration controller provides an option to
dynamically control the adaptive equalization (AEQ) hardware present
in each of the transceiver channels. The AEQ hardware continuously
tunes the receiver equalization settings based on the frequency content of
the incoming signal.
The dynamic data rate switch feature on the transmitter is enabled
through a PLD signal. Depending on the setting of this signal, the
transmitter data rate can be divided in steps of 1, 2, or 4 per channel.
Another important feature is the ability to dynamically reconfigure from
one mode to another mode. This mode reconfiguration may involve
reconfiguring the transceiver data path or data rate or both. You can
reconfigure the transceiver data rate either by switching to the other CMU
PLL or by dynamically reconfiguring the CMU PLL. The former is
enabled in the Quartus
®
II software version 6.1 and later, while the latter
is enabled in the Quartus II software version 7.1 and later.
SIIGX52007-1.1