| 摘要 |
The serial adder/subtracter according to the subject-matter of the invention is constructed by means of an additionally arranged shift circuit 4 in such a manner that the fixed value circuit 1 supplies addition or subtraction result numbers depending on the preceding drive. In this connection, a nines complement circuit is also required because only a nines complement circuit can be used for the required side change of the F inputs. The fixed value circuit 1 supplies addition result numbers when the one-down shift circuit 4 is pre-driven for oblique forwarding and when the side change circuit 3 (nines complement circuit 3) is pre-driven for straight ahead forwarding. The fixed value circuit 1 supplies the subtraction result numbers when the one-down shift circuit 4 is pre-driven for straight ahead forwarding and when the side change circuit 3 (nines complement circuit 3) is pre-driven for side change. <IMAGE>
|
