SYNOPSIS

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

DESCRIPTION

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.

OPTIONS

-a

Uses "Asp" as encoding algorithm.

-j

Uses "Jedi" as encoding algorithm.

-m

Uses "Mustang" as encoding algorithm.

-u

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.

-o

Uses the one hot encoding algorithm.

-r

Uses distinct random numbers for state encoding.

-C

Checks the transition's consistency.

-D

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

-E

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.

-O

With this option syf places registers on the outputs.

-P

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.

-R

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.

-S

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

-V

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

EXAMPLE

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