1NERO(1) Alliance - nero User's Manual NERO(1)
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6 nero - Negotiating Router
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9 nero [ -h ] [ -v ] [ -V ] [ -c ] [ -2 ] [ -3 ] [ -4 ] [ -5 ] [
10 -6 ] [ -L ] [ -G ]
11 [ --help ] [ --verbose ] [ --very-verbose ] [ --core-dump ] [
12 --local ] [ --global ]
13 [ -p placement ] netlist layout
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16 nero is a simple router suited for small academic designs. Currently it
17 can process designs of size up to 4K gates.
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19 GLOBAL ROUTING
20 A design is considered as big if it contains nets which half perimeter
21 is greater than 800 lambdas. Global routing is used on big designs.
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23 In nero, "global routing" means that the longuests nets are completely
24 routed in a first step with only routing layers numbers 3 & 4. Then the
25 smaller nets are routed with all avalaibles layers. This implies that
26 when global routing is used, the number of routing layers is forced to
27 at least 4. In each step, the nets are routed from the shortest to the
28 longuest with the same routing algorithm.
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31 nero mandatory arguments :
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33 · netlist : the name of the design, without any extention. Please note
34 that unless a -p placement option is given, the file holding the
35 placement is expected to have the same name as the netlist file
36 (short of the extention).
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38 · layout : the name of the resulting routed layout. Be careful of not
39 giving the same name as the netlist, in this case the initial place‐
40 ment will be silently overwritten.
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42 nero optionnals arguments :
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44 · -h, --help : print help.
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46 · -v, --verbose : be verbose.
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48 · -V, --very-verbose : be unbearably verbose.
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50 · -c, --core-dump : do not prevent the generation of core dumps in case
51 of a crash. Mostly used during the development stage.
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53 · -2, -3, -4, -5, -6 : set the numbers of layers used for routing. The
54 default for small designs is 2 and 4 for big ones. When global rout‐
55 ing took place, the router will uses at least 4 routing layers.
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57 · -L, --local : turn off the global routing stage, whatever the size of
58 the design. Be warned that this will enormously slow down the rout‐
59 ing process.
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61 · -G, --global : turn on the global routing regardless of the size of
62 the design.
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64 · -p placement, --place placement : specify a name for the placement
65 file different from the netlist name.
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68 Route the netlist amd2901_core.vst, using the placement file
69 amd2901_core_p.ap and store the result in amd2901_core_r.
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71 $ export MBK_IN_LO=vst
72 $ export MBK_IN_PH=ap
73 $ export MBK_OUT_PH=ap
74 $ nero -V --place amd2901_core_p amd2901_core amd2901_core_r
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79 MBK_IN_LO(1), MBK_OUT_LO(1), MBK_IN_PH(1), MBK_OUT_PH(1), ocp(1),
80 ocr(1), druc(1), cougar(1)
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84ASIM/LIP6 13 October 2002 NERO(1)