说明：  This project features a full-hardware sound compressor using the well known algorithm: IMA ADPCM. The core acts as a slave WISHBONE device. The output is perfectly compatible with any sound player with the IMA ADPCM codec (included by default in every Windows). Includes a testbench that takes an uncompressed PCM 16 bits Mono WAV file and outputs an IMA ADPCM compressed WAV file. Compression ratio is fixed for IMA-ADPCM, being 4:1. PLEASE NOTICE THAT THIS CORE IS LICENSED UNDER http://creativecommons.org/licenses/by-nc-sa/3.0/ (Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported). That means you may use it only for NON-COMMERCIAL purposes.