US 5,028,922 A · Multiplexed encoder and decoder with address mark generation/check and precompensation circuits

Abstract

A two-level multiplexed encoder/decoder based on a novel technique of code table compression is disclosed. By means of comparing various code conversion tables such as well-known tables for use in NRZ-MRM, NRZ-RLL conversion schemes, separate code word condition sets are obtained. In accordance with the code word condition sets thus obtained, a two-level multiplexed encode and decode logic can be easily constructed. The code word condition sets representing the compressed code relations are sensed in the first level and are used further to set up the operation of a connected network of a multiplexed logic circuit in the second level. The AM generation/check and precompensation circuit necessary for the encoder and decoder are incorporated as an integral part. This method is applicable when more than two code tables are needed to be integrated in a single encoder/decoder.

Claims15

Dependent claims

An encoder/decoder apparatus for encoding data which is to be encoded prior to insertion in a channel and for decoding encoded data received from said channel, said apparatus comprising:

means for generating a code selection signal specifying one of a plurality of compressed code tables;
an encoder comprising:
encoder code word test means for detecting in said data to be encoded any one of a plurality of code word conditions comprising a first set of code word conditions;
encoder code table multiplexer means for generating an encoded bit stream from the code word conditions of said first set detected in said data by said code word test means in accordance with the one compressed code table specified by said code selection signal;
a decoder comprising:
decoder code word test means for detecting in said encoded data any one of a plurality of code word conditions comprising a second set of code word conditions,
code table multiplexer means for generating a decoded bit stream from the code word conditions of said second set detected in said encoded data by said decoder code word test means in accordance with the one compressed code table specified by said code selection signal.

4 more elements

A method for encoding data which is to be transmitted through a channel, comprising:

generating a code selection signal specifying one of a plurality of compressed code tables;
first detecting in said data which is to be encoded any one of a plurality of code word conditions comprising a first set of code word conditions;
first producing an encoded bit stream from the code word conditions of said first set detected in said data by said first detecting step in accordance with said one compressed code table specified by said code selection signal of said generating step;
and
transmitting said encoded bit stream through said channel;
said method further comprising the following steps for decoding data received from said channel;
receiving a bit stream from said channel;
second detecting in the bit stream received from said channel any one of a plurality of code word conditions comprising a second set of code word conditions;
second producing a decoded bit stream from said code word conditions of said second set detected by said second detecting step in accordance with said one compressed code table specified by said code selection signal of said generating step.

6 more elements

Dependencies are inferred from the claim text.

Multiplexed encoder and decoder with address mark generation/check and precompensation circuits

Life of this patent

Multiplexed encoder and decoder with address mark generation/check and precompensation circuits

Life of this patent

Abstract

Claims15