| 摘要 |
PURPOSE:To reduce the circuit scale and operating time of an accumulator by initializing in advance the content of a register in addition data for rounding calculation. CONSTITUTION:The sum of input data chains DI(n) is obtained by a series of arithmetic operations. However, addition data R (R=2<m>) for rounding calculation are set in a register 2 in advance under the control of an initialization circuit 6. Namely, Q(0)=R. The total sum of the input data chains DI(n) is found to an output Q(N) from the series of arithmetic operations, but rounding calculation can be realized when the calculated result DO is outputted after the result is shifted rightward by means of a shifter 5 and bits lower than the 2<m> figure are discarded from the result, because the sum of the input data chains DI(n) has been added to the data R (R=2<m>) for rounding calculation. Therefore, no adder is required for the rounding calculation and, accordingly, the calculating time can be reduced. |
