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| -rw-r--r-- | README.md | 67 |
1 files changed, 19 insertions, 48 deletions
@@ -130,18 +130,15 @@ commands and ``help <command>`` to print details on the specified command: yosys> help help -reading the design using the Verilog frontend: +reading and elaborating the design using the Verilog frontend: - yosys> read_verilog tests/simple/fiedler-cooley.v + yosys> read -sv tests/simple/fiedler-cooley.v + yosys> hierarchy -top up3down5 writing the design to the console in Yosys's internal format: yosys> write_ilang -elaborate design hierarchy: - - yosys> hierarchy - convert processes (``always`` blocks) to netlist elements and perform some simple optimizations: @@ -163,51 +160,26 @@ write design netlist to a new Verilog file: yosys> write_verilog synth.v -a similar synthesis can be performed using yosys command line options only: - - $ ./yosys -o synth.v -p hierarchy -p proc -p opt \ - -p techmap -p opt tests/simple/fiedler-cooley.v - or using a simple synthesis script: $ cat synth.ys - read_verilog tests/simple/fiedler-cooley.v - hierarchy; proc; opt; techmap; opt + read -sv tests/simple/fiedler-cooley.v + hierarchy -top up3down5 + proc; opt; techmap; opt write_verilog synth.v $ ./yosys synth.ys -It is also possible to only have the synthesis commands but not the read/write -commands in the synthesis script: - - $ cat synth.ys - hierarchy; proc; opt; techmap; opt - - $ ./yosys -o synth.v tests/simple/fiedler-cooley.v synth.ys - -The following very basic synthesis script should work well with all designs: - - # check design hierarchy - hierarchy - - # translate processes (always blocks) - proc; opt - - # detect and optimize FSM encodings - fsm; opt - - # implement memories (arrays) - memory; opt - - # convert to gate logic - techmap; opt - If ABC is enabled in the Yosys build configuration and a cell library is given in the liberty file ``mycells.lib``, the following synthesis script will synthesize for the given cell library: + # read design + read -sv tests/simple/fiedler-cooley.v + hierarchy -top up3down5 + # the high-level stuff - hierarchy; proc; fsm; opt; memory; opt + proc; fsm; opt; memory; opt # mapping to internal cell library techmap; opt @@ -222,7 +194,8 @@ synthesize for the given cell library: clean If you do not have a liberty file but want to test this synthesis script, -you can use the file ``examples/cmos/cmos_cells.lib`` from the yosys sources. +you can use the file ``examples/cmos/cmos_cells.lib`` from the yosys sources +as simple example. Liberty file downloads for and information about free and open ASIC standard cell libraries can be found here: @@ -231,20 +204,18 @@ cell libraries can be found here: - http://www.vlsitechnology.org/synopsys/vsclib013.lib The command ``synth`` provides a good default synthesis script (see -``help synth``). If possible a synthesis script should borrow from ``synth``. -For example: +``help synth``): - # the high-level stuff - hierarchy - synth -run coarse + read -sv tests/simple/fiedler-cooley.v + synth -top up3down5 - # mapping to internal cells - techmap; opt -fast + # mapping to target cells dfflibmap -liberty mycells.lib abc -liberty mycells.lib clean -Yosys is under construction. A more detailed documentation will follow. +The command ``prep`` provides a good default word-level synthesis script, as +used in SMT-based formal verification. Unsupported Verilog-2005 Features |