Altera Cyclone IV - Page 426

3–28 Chapter 3: Cyclone IV Dynamic Reconfiguration
Dynamic Reconfiguration Modes
Cyclone IV Device Handbook, November 2011 Altera Corporation
Volume 2
Clocking/Interface Options
The following describes the Clocking/Interface options available in Cyclone IV GX
devices. The core clocking setup describes the transceiver core clocks that are the
write and read clocks of the Transmit Phase Compensation FIFO and the Receive
Phase Compensation FIFO, respectively. Core clocking is classified as transmitter core
clocking and receiver core clocking.
Table 3–6 lists the supported clocking interface settings for channel reconfiguration
mode in Cyclone IV GX devices.
Transmitter core clocking refers to the clock that is used to write the parallel data from
the FPGA fabric into the Transmit Phase Compensation FIFO. You can use one of the
following clocks to write into the Transmit Phase Compensation FIFO:
■ tx_coreclk —you can use a clock of the same frequency as tx_clkout from the
FPGA fabric to provide the write clock to the Transmit Phase Compensation FIFO.
If you use
tx_coreclk , it overrides the tx_clkout options in the ALTGX
MegaWizard Plug-In Manager.
■ tx_clkout —the Quartus II software automatically routes tx_clkout to the FPGA
fabric and back into the Transmit Phase Compensation FIFO.
Table 3–6. Dynamic Reconfiguration Clocking Interface Settings in Channel Reconfiguration
Mode
ALTGX Setting Description
Dynamic Reconfiguration Channel Internal and Interface Settings
How should the receivers be
clocked?
Select one of the available options:
■ Share a single transmitter core clock between receivers
■ Use the respective channel transmitter core clocks
■ Use the respective channel receiver core clocks
How should the transmitters be
clocked?
Select one of the available options:
■ Share a single transmitter core clock between transmitters
■ Use the respective channel transmitter core clocks