JavaFSM

by Karola Krönert and Ulrich Dallmann

ENGLISH translation by Holger Rehmeier
IPCT, PUCRS, BRASIL (moore tools)


The processing of binary information takes place in digital computers with help of logical circuits.

A network has n inputs  and m outputs:

At the inputs, binary values  x1,x2,..., xn with xi out of {0,1}can be input. At the outputs, binary words are output according to the input-signals y1,y2,..., ym with yi out of {0,1}.

Is the output only refering to its momentarily input, so it is named control-network. Is it also refering to former outputs (repatriation of the outputs), so it is called a control-mechanism. Information can be stored by means of the repatriation.

As direct repatriations are rarely easy to handle even with small control mechanisms (Hazards),  a clock-device is inserted into the repatriation. For a better overview,  the switch-network is divided into two parts: the first part is used for the regulation of the consequence-state (delta-switch-network), the second calculates the edition-values (Lambda-Schaltnetz).

The control-mechanism is designed as follows:

Schaltnetz


 


Delta-switch-network: here, out of the state, in which the machine is now, and the input-condition the following state is calculated. 
Bar-limb: here, the condition in which the machine is now is stored by Flip-Flops. With a clock-signal, the following condition, that has been computed by the delta-network,  becomes the new condition in the delta- and lambda-network. A condition-alteration can only take place with a clock-signal. 
Lambda-network: the current outputs are calculated here. With a Moore-machine, these refer only to the current condition. However with a Mealy-machine, also the inputs are included to the calculations. So, also between two clock-signals alterations can be generated. Mealy-machines are not mightier however, because (apart from a delay) there is always an equivalent Moore-machine. 

 
Moore-Schaltwerk
Mealy-Schaltwerk

 An important description-method for control mechanisms are Finite State Machines. JavaFSM uses these for the design  and offers the possibility, to export defined machines as control mechanisms to VHDL and KISS.


JavaFSMTECHUlrich DallmannKarola Krönert