EP3C16F256I7 Altera, EP3C16F256I7 Datasheet - Page 245

• Manufacturer Part Number: EP3C16F256I7
• Description: Cyclone III
• Manufacturer: Altera

Altera Corporation-Preliminary
March 2007
Configuration Data Decompression
Cyclone III devices support configuration data decompression, which
saves configuration memory space and time. This feature allows you to
store compressed configuration data in configuration devices or other
memory and transmit this compressed bitstream to Cyclone III devices.
During configuration, Cyclone III devices decompress the bitstream in
real time and programs its SRAM cells.
1
Cyclone III devices support decompression in the AS and PS
configuration schemes. Decompression is not supported in the AP
configuration scheme, FPP configuration scheme, or in JTAG-based
configuration.
In PS mode, you should use the Cyclone III decompression feature
because sending compressed configuration data reduces configuration
time. You should use the Cyclone III decompression feature during AS
configuration if you need to save configuration memory space in the
serial configuration device.
When you enable compression, the Quartus II software generates
configuration files with compressed configuration data. This compressed
file reduces the storage requirements in the configuration device or flash
memory and decreases the time needed to transmit the bitstream to the
Cyclone III device. The time required by a Cyclone III device to
decompress a configuration file is less than the time needed to transmit
the configuration data to the device.
There two methods for enabling compression for Cyclone III bitstreams
in the Quartus II software:
■
■
To enable compression in the project’s compiler settings, perform the
following steps in the Quartus II software:
1.
2.
3.
Before design compilation (in the Compiler Settings menu)
After design compilation (in the Convert Programming Files
window).
On the Assignment menu, click Device. The Settings dialog box
appears.
Click Device & Pin Options. The Device & Pin Options dialog box
appears.
Click the Configuration tab.
Preliminary data indicates that compression typically reduces
configuration bitstream size by 35 to 55%.
Cyclone III Device Handbook, Volume 1
Configuration Features
10–9