Abstract: A look-up table (LUT) is arranged as a plurality of rows each indexed by an index value and storing at least a coefficient for each index value for use in processing digital data. The LUT contains repeated sections in which m coefficients stored for successive index values form a cycle. The number m is not an integer power of 2. For example the LUT may be used when converting a digital count to a gain in dB, in which case m may be 6 or 12, the coefficients representing dB or fractional-dB steps in gain. The LUT contains n additional blank rows inserted after every repeated section of m rows storing the cycle of m coefficients, n being 1 or more and (m+n) being an integer power of two (such as 8 or 16). By feeding an initial index value through encoding logic which takes account of the additional rows, it can be ensured that these are never indexed. Thus, a sparse-coded LUT is provided.

Abstract: A look-up table (LUT) is arranged as a plurality of rows each indexed by an index value and storing at least a coefficient for each index value for use in processing digital data. The LUT contains repeated sections in which m coefficients stored for successive index values form a cycle. The number m is not an integer power of 2. For example the LUT may be used when converting a digital count to a gain in dB, in which case m may be 6 or 12, the coefficients representing dB or fractional-dB steps in gain. The LUT contains n additional blank rows inserted after every repeated section of m rows storing the cycle of m coefficients, n being 1 or more and (m+n) being an integer power of two (such as 8 or 16). By feeding an initial index value through encoding logic which takes account of the additional rows, it can be ensured that these are never indexed. Thus, a sparse-coded LUT is provided.