| yosys -import | 
 | plugin -i sdc | 
 | # Import the commands from the plugins to the tcl interpreter | 
 | yosys -import | 
 |  | 
 | read_verilog pll.v | 
 | read_verilog -specify -lib -D_EXPLICIT_CARRY +/xilinx/cells_sim.v | 
 | read_verilog -lib +/xilinx/cells_xtra.v | 
 | hierarchy -check -auto-top | 
 |  | 
 | # Start flow after library reading | 
 | synth_xilinx -vpr -flatten -abc9 -nosrl -nodsp -iopad -run prepare:check | 
 |  | 
 | # Read the design timing constraints | 
 | read_sdc $::env(INPUT_SDC_FILE) | 
 |  | 
 | # Propagate the clocks | 
 | propagate_clocks | 
 |  | 
 | # Write out the SDC file after the clock propagation step | 
 | write_sdc $::env(OUTPUT_SDC_FILE) |