Signs is a tool for logic synthesis and gate level simulation. Signs's project main features include synthesis of RTL-style VHDL circuit descriptions and a dynamic graphical netlist viewer.
Supported formats include VHDL, ISCAS, and limited support for BLIF, Verilog, and EDIF netlists. Various true value and fault simulators and a combinational ATPG are included for circuit testing.
Aside from GUI mode, Signs has a pure command line mode and is fully scriptable in JavaScript and Ruby.
Here are some key features of "Signs":
· Written in Java, therefore platform-independent
· Aims to be VHDL93 compliant, at the moment a VHDL Subset is supported
· (Limited) support for non-synthesizable VHDL code, useful for testbenches
· Synthesis of RTL-style sequential VHDL process descriptions according to IEEE Std 1076.6
· Dynamic graphical netlist viewer supporting annotations (signal/gate names, signal values provided by simulators, faults)
· VHDL netlist output to file
· Input and output of netlists in ISCAS benchmark format
· Gate level true value simulators: event-based (any circuit), bit-parallel (combinational circuits only)
· Fault simulators: PPSFP, simple single faultsim
· Input and output of pattern lists in WGL format
· ATPG for combinational circuits: Implication-Graph based, PODEM
· Limited support for Verilog and EDIF netlists
· Fully scriptable in Rhino: JavaScript for Java and JRuby
· Pure command-line mode available besides GUI mode
· Integrated environment including source code and netlist structure tree views, build system, compilers and editors with syntax highlighting
What's New in This Release:
· While the release focus is clearly on bugfixes, there are also some feature improvements, such as enhanced test bench support and improved netlist and simulator views.
· The VHDL compiler has support for subprograms now and elaboration of big designs is much faster because of improved context handling.
· Internally, the intermediate representation layer was cleaned up, so intermediate objects form a proper tree now.
