Adressenerzeugungsschaltung für eine zweidimensionale Kodierungstabelle bei einem Huffman Code

摘要

Circuit for generating the address in a look-up table used for converting two values x and y, corresponding respectively to two events A and B, into one variable length code. Each combination (x,y) corresponds to one address in the table. An escape code instead of a codeword from the table is used if x+log2(y)>P or if y+log2(x)>P (codes with low occurence probability). The circuit comprises:

coincidence detectors (1a-1g) which detects if at least one of the input x or y takes a value between x and S (S is the biggest integer satisfying S+log2(S) Use: entropy coding of two-dimensional datas like television picture or wind direction/wind velocity.