PPT Slide
4 – Combinational Logic Design Examples
Combinational logic design process
- formalize problem: encodings, truth-table, equations
- choose implementation technology (ROM, PAL, PLA, discrete gates)
- implement by following the design procedure for that technology
Binary number representation
- positive numbers the same
- difference is in how negative numbers are represented
- 2s complement easiest to handle
- one representation for zero
- slightly complicated complementation
- simple addition
Circuits for binary addition
- basic half-adder and full-adder
- carry lookahead logic
- carry-select
ALU Design
- specification, implementation