Hi all,

I try also an explanation:

A state machine is a machine, which calculate the next state as a function of the current state and some inputs.
If the state was represented by 8 bit then 256 different states can be entered. These 8 bits can be used direct as 8 outputs or feed into a decoder.

Also some special state machines conceivable:
On a counter the next state only depends from the current state, the inputs are dont care.
On a logic gate only the inputs used and the current state was ignored.

An easy representation is a 27C512 EPROM with a D-FF (57) to feed back the 8 data outputs to 8 address inputs. The other 8 adress inputs are inputs of the state machine. Any pulse on the clock input of the D-FF cause entering the next state.
Then you must only program for every address input the desired next state.

A simple example of a state machine is a washing machine.
There are some states (off, fill water, washing, heating, pump water, ..) and the inputs are a program switch, fill sensors, temperature sensors.
E.g. if the current state was "heating on" and the temperature input was "temperature to low" so the next state was also "heating on", otherwise "heating off".
The pulse frequency to enter the next state was generated from a timer.


Peter