syf.1alc - Man Page

Finite State Machine synthesizer.


syf -a|j|m|u|o|r [-CDEOPRSTV] input_name [output_name]


syf is a Finite State Machine synthesizer. syf allows a fast generation of VHDL Data Flow description (see vbe(5)) from a VHDL Finite State Machine description (see fsm(5)). The input FSM specification can use an internal STACK. Both MOORE and MEALEY FSMs can be synthesized, with output registers if desired. For a MOORE FSM, a timing-optimized implementation that emulates a ROM with microsequencer is possible. A scan-path for the state registers can also be implemented.

Environment Variables


indicates the path to the read/write directory for the session.



Uses "Asp" as encoding algorithm.


Uses "Jedi" as encoding algorithm.


Uses "Mustang" as encoding algorithm.


Uses an encoding given by user through <input_name>.enc file. In this file, a line started by a # character is a comment. A valid line contains one state name followed by its hexadecimal code.


Uses the one hot encoding algorithm.


Uses distinct random numbers for state encoding.


Checks the transition's consistency.


With this option syf doesn't optimize unused, i.e Don't Care, codes.


Saves the encoding result in the <output_name>.enc. This file has the same syntax as <input_name>.enc file which is used by -u option.


With this option syf places registers on the outputs.


Implements a scan-path for the state registers, stack registers and possibly output registers. Scan-path mechanism is directely included in states decoder. Users should use scapin(5) for a correct insertion of a scan-path in a netlist. Please check fsm(5) for information about scan-path descriptions.


This option is only available for MOORE FSM. With this option, syf emulate s a ROM with micro-sequencer implementation : there is no combinatorial logic between the state registers and the FSM outputs. This can be mandatory for external timing constraints. See fsm(5) and grog(1) for more on ROM descriptions.


With this option syf doesn't take into account the cost of the transitions to compute an encoding.


Verbose mode on. Each step of the FSM synthesis is displayed on the standard output, along with some statistics.


Environment variables:

setenv MBK_WORK_LIB /alliance/tutorials/dlxm

syf is called as follow (the dlx_ctrl.fsm is already created in /alliance/tutorials/dlxm) :

syf -sE dlx_ctrl

Two files will be generated, a states encoding file dlx_ctrls.enc and a VHDL data flow file /alliance/tutorials/dlxm/dlx_ctrls.vbe

See Also

fsm(5), vbe(5), vhdl(5), boom(1), boog(1), loon(1), scapin(1), asimut(1), proof(1), MBK_WORK_LIB(1).

Referenced By


October 1, 1997 ASIM/LIP6 CAO-VLSI Reference Manual