[Solved] Can hazards increase switching time and/or number of switchings?

katang Asks: Can hazards increase switching time and/or number of switchings?
In connection with question CMOS gate logic switching time based on input vectors one of the answers mentioned hazards. Although the question was about the switching time, finally I did not find the answer to the question. Say, we have several one-bit adders, chained, and the lower carry out bits provide inputs for the next carry in bits. When adding an all-one number and 1 (and we do not have special handling of carry), the first carry is set with some time delay, causes to recalculate the next bit with some more delay, and so on. In a 64-bit adder, at the end of the chain it can be a considerable delay. Depending on the relation between the transfer-to-the-next-bit to switching-time, the new carry-in inputs may arrive at different times with respect to the arrival of the two summand bits. That is (I expect) it may affect the operation: it may cause not only glitches, but also unwanted switching. I.e., I expect that it may cause increase in switching time, if the changed carry-in appears in an early phase of switching, and may cause additional switching if it arrives in a later phase. What are the timing relations here (I mean wiring delay till the next adder(s) to switching time)? (if we consider this operation as a “computation”, the arrival of any of the input operands starts the computation, and the arrival of the next operand starts the computation again, in parallel with the previous one. In biology, there exists a “refractory” period, which limits parallel operation; in electronics, as far as I know, no similar limitation exists. How then this unwanted parallelization is handled?)

Ten-tools.com may not be responsible for the answers or solutions given to any question asked by the users. All Answers or responses are user generated answers and we do not have proof of its validity or correctness. Please vote for the answer that helped you in order to help others find out which is the most helpful answer. Questions labeled as solved may be solved or may not be solved depending on the type of question and the date posted for some posts may be scheduled to be deleted periodically. Do not hesitate to share your response here to help other visitors like you. Thank you, Ten-tools.