
3.7 LOGIC LEVEL INCOMPATIBILITY: COMPLEMENTATION 95
fan-in requirements. For reference purposes, the ANSI/IEEE Standard logic symbols for
gates are provided in Appendix C.1.
3.7 LOGIC LEVEL INCOMPATIBILITY: COMPLEMENTATION
The eight conjugate gate symbols in Fig. 3.20b perform one of two logic operations, AND
or OR, regardless of the presence or absence of the active low indicator bubbles that serve
to associate the symbols to the physical gates from which they are derived. However, the
presence or absence of an active low indicator bubble on the input to a given circuit symbol
indicates the activation level of the input, (L) or (H), that is “required” ...