DCT MATRIX ARITHMETIC CIRCUIT

摘要

PURPOSE:To reduce the number of multipliers and adders and to reduce the gate scale of an arithmetic circuit. CONSTITUTION:A DTC converstion coefficient is stored in a coefficient ROM part 1 and a multiplication part 2 multiplies input data by the DCT conversion coefficient. An addition part 3 adds a multiplication result with a previous operation result selected in a selector 5 and a result is held in plural registers 4. At that time, a control part 6 selects the inputs of the plural registers 4 and selects the output of the selector 5. A processing for sequentially multiplying and adding to one piece of input data by the plural DCT conversion coefficients from the coefficient ROM part 1 and for sequentially updating the plural registers 4 by the operation result is executed for the number of elements times in the row-direction of a DCT matrix. The request of the row-direction of the ECT matrix is obtained and the operation is executed for the number of the elements times of the column-direction of the DCT matrix. Then, all the elements in the row-direcion and the column-direction of the DCT matrix are obtained.