Configuration Handbook - Kamami.pl

Configuration FeaturesStratix III devices support decompression in the FPP (when using aMAX II device/microprocessor + flash), fast AS, and PS configurationschemes. The Stratix III decompression feature is not available in the FPP(when using enhanced configuration device) and JTAG configurationschemes.1 When using FPP mode, the intelligent host must provide a DCLKthat is 4× the data rate. Therefore, the configuration data must bevalid for four DCLK cycles.The decompression feature supported by Stratix III devices is differentfrom the decompression feature in enhanced configuration devices(EPC16, EPC8, and EPC4), although they both use the same compressionalgorithm. The data decompression feature in the enhanced configurationdevices allows them to store compressed data and decompresses thebitstream before transmitting it to the target devices. When usingStratix III devices in FPP mode with enhanced configuration devices, thedecompression feature is available only in the enhanced configurationdevice, not in the Stratix III device.In PS mode, use the Stratix III decompression feature because sendingcompressed configuration data reduces configuration time.1 Do not use both the Stratix III device and the enhancedconfiguration device decompression feature simultaneously.The compression algorithm is not intended to be recursive andcould expand the configuration file instead of compressing itfurther.When you enable compression, the Quartus II software generatesconfiguration files with compressed configuration data. This compressedfile reduces the storage requirements in the configuration device or flashmemory, and decreases the time needed to transmit the bitstream to theStratix III device. The time required by a Stratix III device to decompressa configuration file is less than the time needed to transmit theconfiguration data to the device.There are two ways to enable compression for Stratix III bitstreams:before design compilation (in the Compiler Settings menu) and afterdesign compilation (in the Convert Programming Files window).To enable compression in the project's Compiler Settings menu,1. Select Device under the Assignments menu to bring up the Settingswindow.11–6 Altera CorporationStratix III Device Handbook, Volume 1 May 2007