check - check for obvious problems in the design

    check [options] [selection]

This pass identifies the following problems in the current design:

  - combinatorial loops
  - two or more conflicting drivers for one wire
  - used wires that do not have a driver

Options:

    -noinit
        also check for wires which have the 'init' attribute set

    -initdrv
        also check for wires that have the 'init' attribute set and are not
        driven by an FF cell type

    -mapped
        also check for internal cells that have not been mapped to cells of the
        target architecture

    -allow-tbuf
        modify the -mapped behavior to still allow $_TBUF_ cells

    -assert
        produce a runtime error if any problems are found in the current design