NAME

       nero - Negotiating Router

SYNOPSIS

       nero [ -h ]  [ -v ]  [ -V ]  [ -c ]  [ -2 ]  [ -3 ]  [ -4 ]  [ -5 ]  [ -6 ]  [ -L ]  [ -G ]
        [ --help ]  [ --verbose ]  [ --very-verbose ]  [ --core-dump ]  [ --local ]  [ --global ]
        [ -p placement ]  netlist layout

DESCRIPTION

       nero is a simple router suited for small academic designs. Currently it can process designs of size up to
       4K gates.

   GLOBAL ROUTING
       A  design  is  considered  as  big  if it contains nets which half perimeter is greater than 800 lambdas.
       Global routing is used on big designs.

       In nero, "global routing" means that the longuests nets are completly routed in a first  step  with  only
       routing  layers  numbers 3 & 4. Then the smaller nets are routed with all avalaibles layers. This implies
       that when global routing is used, the number of routing layers is forced to at least 4.   In  each  step,
       the nets are routed from the shortest to the longuest with the same routing algorithm.

INVOCATION

       nero mandatory arguments :

       • netlist : the name of the design, whithout any extention. Please note that unless a -p placement option
         is  given,  the file holding the placement is expected to have the same name as the netlist file (short
         of the extention).

       • layout : the name of the resulting routed layout. Be careful  of  not  giving  the  same  name  as  the
         netlist, in this case the initial placement will be silently overwritten.

       nero optionnals arguments :

       • -h, --help : print help.

       • -v, --verbose : be verbose.

       • -V, --very-verbose : be unbearably verbose.

       • -c,  --core-dump :  do not prevent the generation of core dumps in case of a crash.  Mostly used during
         the development stage.

       • -2, -3, -4, -5, -6 : set the numbers of layers used for routing. The default for small designs is 2 and
         4 for big ones. When global routing took place, the router will uses at least 4 routing layers.

       • -L, --local : turn off the global routing stage, whatever the size of the design.  Be warned that  this
         will enormously slow down the routing process.

       • -G, --global : turn on the global routing regardless of the size of the design.

       • -p  placement,  --place  placement :  specify  a name for the placement file different from the netlist
         name.

EXAMPLE

       Route the netlist amd2901_core.vst, using the placement file amd2901_core_p.ap and store  the  result  in
       amd2901_core_r.

       $ export MBK_IN_LO=vst
       $ export MBK_IN_PH=ap
       $ export MBK_OUT_PH=ap
       $ nero -V --place amd2901_core_p amd2901_core amd2901_core_r

SEE ALSO

       MBK_IN_LO(1), MBK_OUT_LO(1), MBK_IN_PH(1), MBK_OUT_PH(1), ocp(1), ocr(1), druc(1), cougar(1)

ASIM/LIP6                                        13 October 2002                                         NERO(1)