Example I: A combinational system
A simple calendar subsystem
- The logic computes the number of days in a month
- Used to control a wrist-watch LCD display
- Inputs: month, leap year flag
- Outputs: number of days in the month
In software terms
- A function whose output depends only on its input (parameters)
- Does not depend on system state or previous outputs of the function
- To be implemented in hardware:
- Data must be encoded in digital form
- Behavior (procedure) must be expressed as logic