|
Logic redundancy occurs in a digital gate network containing circuitry that does not affect the static logic function. There are several reasons why logic redundancy may exist. One reason is that it may have been added deliberately to suppress transient glitches (thus causing a race condition) in the output signals by having two or more product terms overlap with a third one. Consider the following equation: : The third product term is a redundant consensus term. If switches from 1 to 0 while and , remains 1. During the transition of signal in logic gates, both the first and second term may be 0 momentarily. The third term prevents a glitch since its value of 1 in this case is not affected by the transition of signal . Another reason for logic redundancy is poor design practices which unintentionally result in logically redundantly terms. This causes an unnecessary increase in network complexity, and possibly hampering the ability to test manufactured designs using traditional test methods (single stuck-at fault models). (Note: testing might be possible using IDDQ models.) ==Removing logic redundancy== Logic redundancy is, in general, not desired. Redundancy, by definition, requires extra parts (in this case: logical terms) which raises the cost of implementation (either actual cost of physical parts or CPU time to process). Logic redundancy can be removed by several well-known techniques, such as Karnaugh maps, the Quine–McCluskey algorithm, and the heuristic computer method. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「logic redundancy」の詳細全文を読む スポンサード リンク
|