| 摘要 |
PURPOSE:To reduce the degree of dependence upon software and also to decrease the number of processing steps in order to increase the processing speed of an addition/subtraction device for decimal numbers, by providing a logic arithmetic circuit and using an operator calculated by said arithmetic circuit to perform the operation of absolute values of two numbers. CONSTITUTION:Two numbers are stored in registers 21 and 2$2d respectively and the codes of these numbers are supplied to a logic arithmetic circuit 1 from the digit positions accordant with these code types together with an operator showing the addition or subtraction via code selecting circuits 51 and 52 and code checking circuits 61 and 62. The circuit 1 performs a logic operation to obtain a desired operator from the codes showing the plus and minus of two numbers to undergo operations and said operator. While the absolute value excluding the code parts of those two numbers stored in registers 21 and 22 is sent to a decimal number arithmetic circuit 4. The circuit 4 performs an operation with the operator received from the circuit 1 under the control of an arithmetic indication means 3. If the number (a) obtained by the operation is negative, the obtained plus and minus codes are inverted to obtain a desired arithmetic result.
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