SINE/COSINE LOOK-UP TABLE

摘要

PROBLEM TO BE SOLVED: To obtain a look-up table which reduces conversion time by providing a complement circuit, a memory and a switching element which receives plural numeric values from the memory and selectively outputs a numeric value based on a most significant bit. SOLUTION: A look-up table includes a complement circuit 303, a memory array 305 and a switching element 307. The circuit 303 selectively takes a complement about a subset of address bits of plural bits of a certain angle based on the most significant bit of an address of plural bits in order to produce an address signal. The memory is addressed by an address signal and generates two numeric values. The element 307 receives the two numeric values from the memory and selectively outputs a numeric value based on the most significant bit. The look-up table can be included by an integrated circuit device such as a modem which makes an integrated circuit a base.