If two 4 bit numbers are being added in the Adder/Subtractor unit e.g. X and Y. Then according to my text book it is written that the Add/Sub Unit is built in a way that the add/sub signal (which chooses whether to add/subtract) is XOR with Y (the position where the number that is to be complemented is entered). But what if the user wants to enters { -5-3 }.How will the add/sub unit work then? Should the X input be also XOR with another signal similar to add/sub?(adsbygoogle = window.adsbygoogle || []).push({});

-Thanks

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# Adder and Subtractor Unit

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