extract_counter - Extract GreenPak4 counter cells

    extract_counter [options] [selection]

This pass converts non-resettable or async resettable down counters to
counter cells. Use a target-specific 'techmap' map file to convert those cells
to the actual target cells.

    -maxwidth N
        Only extract counters up to N bits wide

    -pout X,Y,...
        Only allow parallel output from the counter to the listed cell types
        (if not specified, parallel outputs are not restricted)