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)