摘要 |
A variable length decoder for decoding an input digital data stream which includes a plurality of variable length code words which are coded in accordance with any of a plurality of different coding standards. The variable length decoder includes an input circuit which receives the input digital data stream and produces a decoding window that includes a leading word aligned bit stream, and a decoding circuit which is configurable into any selected one of a plurality of different decoding configurations, depending upon which coding standard the input digital data stream is coded in accordance with, the decoding circuit being coupled to the leading word aligned bit stream for decoding the length and value of each code word in the input digital data stream. The variable length decoder further includes a programmable controller for controlling the operation of the variable length decoder in accordance with any of a plurality of different decoding protocols, depending upon the coding standard employed in coding the input digital data stream. The programmable controller determines which coding standard was employed in coding the input digital data stream, and then automatically configures the decoding circuit into the decoding configuration which is appropriate for decoding the input digital data stream, based upon this determination. The variable length decoder also includes a code word value memory which is used for decoding the values of the code words in the input digital data stream.
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