EP2C20F256C8N Datasheet, PDF (369/470 Pages) Altera Corporation – Cyclone II Device Handbook, Volume 1

Configuring Cyclone II Devices
If the configuration bitstream size exceeds the capacity of a serial
configuration device, you must select a larger configuration device
and/or enable the compression feature. When configuring multiple
devices, the size of the bitstream is the sum of the individual devices'
configuration bitstreams.
Configuring Multiple Cyclone II Devices with the Same Design
Certain designs require you to configure multiple Cyclone II devices with
the same design through a configuration bitstream or SOF. You can do
this through one of two methods, as described in this section. For both
methods, the serial configuration devices cannot be cascaded or chained
together.
Multiple SOFs
In the first method, two copies of the SOF file are stored in the serial
configuration device. Use the first copy to configure the master Cyclone II
device and the second copy to configure all remaining slave devices
concurrently. In this setup, the master Cyclone II device is in AS mode,
and the slave Cyclone II devices are in PS mode (MSEL=01). See
Figure 13–5.
To configure four identical Cyclone II devices with the same SOF file,
connect the three slave devices for concurrent configuration as shown in
Figure 13–5. The nCEO pin from the master device drives the nCE input
pins on all three slave devices. Connect the configuration device’s DATA
and DCLK pins to the Cyclone II device’s DATA and DCLK pins in parallel.
During the first configuration cycle, the master device reads its
configuration data from the serial configuration device while holding
nCEO high. After completing its configuration cycle, the master drives
nCE low and transmits the second copy of the configuration data to all
three slave devices, configuring them simultaneously.
The advantage of using the setup in Figure 13–5 is that you can have a
different SOF file for the Cyclone II master device. However, all the
Cyclone II slave devices must be configured with the same SOF file. The
SOF files in this configuration method can be either compressed or
uncompressed.
1
You can still use this method if the master and slave Cyclone II
devices use the same SOF.
Altera Corporation
February 2007
13–15
Cyclone II Device Handbook, Volume 1