Parameter Tab - 2.1 English

The following is an image of the Parameter tab in the Compression mode:

The following is an image of the Parameter tab in the Decompression mode:

Compression/Decompression Mode

Select either Compression/Decompression mode.

File Compression Standard

Choose the suitable File Compression Standard from the drop-down options. Possible options for this parameter are:

• Compression mode: GZIP, ZLIB
• Decompression mode: GZIP, ZLIB, and 'GZIP and ZLIB'.

When GZIP option is selected, CRC32 checksum calculation module gets used, whereas if ZLIB option is selected, Adler checksum calculation module gets used. 'GZIP and ZLIB' can be selected to support both the standards simultaneously which uses both CRC32 and Adler checksum calculation modules to validate the checksum present in the compressed file.

History Window Size

For the Compression mode, it is fixed to 32768. For the Decompression mode, select the suitable History Window Size from the drop-down options. Possible options for this parameter are 32768, 16384, 8192, 4096. Use the same or higher History Window Size that the input file is compressed with. If you do not know the size used in compressing the file, use the default value of 32768.

Input Data Width

For the Compression mode, the input data width is fixed to 256. For the Decompression mode, choose the suitable Input Data Width from the drop-down options. Possible options for this parameter are 512, 256, 128, 64, 32. We recommend using the default 128-bit input data width option for optimal resource and performance.

Enable Output FIFO

Applicable only for the Compression mode. Select this option to enable backpressure support for Compression IP. Also, enabling this option will have a resource impact of up to 8 additional BRAMs.

Enable Shortest Distance for LZ77

Applicable only for the Compression mode. Enable this option to select the shortest distance value during LZ77 compression to have better compression ratio.