Digital System

A digital system comprises of the following

• datapath - transforms the data as required by a specification
• controller - (control unit, control path) - monitors and controls the datapath signals and controls

Bus

To connect all of the different devices together, we need a data bus; however we need to manage which devices are reading from, and which single (important) devices are writing to a bus - else we will have value corruption.

Output Selection

As all devices will have a continuous output, a multiplexer can be used to determine which device output is routed into the bus

A tristate buffer (hence using one-hot encoding) could also be used

ASM - Algorithmic State Machines

ASMs represent state transitions and generated outputs that may be difficult to represent as state diagrams and state tables.

Named State Box	Decision Box	Conditional Output Box