These are circuits where the output depends solely on the current input. The Digital Electronics syllabus emphasizes: Multiplexers/Demultiplexers: The "traffic cops" of data. Encoders/Decoders:
Flip-flops are the heart of the syllabus. Memorize the excitation tables (What input is required to go from Q=0 to Q=1 for a JK FF?). Bakshi provides a unique "Conversion Table" that is worth memorizing. digital electronics by bakshi and godse pdf
If you are looking for the PDF, you likely need to master the following modules, all of which are exhaustively covered in the text. These are circuits where the output depends solely