


GLROUTE(1ICD)		     7/29/87		    GLROUTE(1ICD)



NNNNAAAAMMMMEEEE
     glroute - automatic/interactive global routing program

SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
     ggggllllrrrroooouuuutttteeee [----iiiiccccpppp3333ffffwwwwaaaassssPPPPmmmm] [----gggg graphics] [----dddd device_name] [----nnnn
     iterations] [----VVVV vdd_name] [----GGGG gnd_name] [----oooo outp_name]
     flp_cell_name [cir_cell_name]

OOOOPPPPTTTTIIIIOOOONNNNSSSS
     If the circuit cell name is not specified, the same name is
     used as the floorplan cell name.

     One of the following options can be specified:

     ----iiii   Interactive mode.

     ----gggg   The name of a graphics terminal.  The following graph-
	  ics terminals are supported:
	  apollo_15_color, hp2397, hp98700, hpgp, rast10.  If
	  this option is not specified, the graphics terminal is
	  obtained from the environment variable TERM.

     ----dddd   The name of the output device.

     ----nnnn   The number of compaction iterations desired (default
	  0).  If this option is used, the placement will be
	  modified locally according to the routing space needed.
	  If -c option is set, -n option will not work.

     ----cccc   Read routing channels from the database.  No channels
	  are generated in the _g_l_r_o_u_t_e.  Use this option if chan-
	  nels are entered manually in _i_p_p.

     ----pppp   Normally the power and ground nets are routed using a
	  special strategy to guarantee that they do not cross
	  each other.  Power terminals on the left and bottom
	  sides and ground terminals on the right and top sides
	  on the instances are ignored.  However, if the -p
	  option is used, the power and ground nets are routed as
	  ordinary nets.

     ----PPPP   Also route power supply terminals on the bottom and
	  left side of the cells and ground terminals on the top
	  and right side of the cells.	However these terminals
	  are not guaranteed to be routed in metal.

     ----mmmm   Prevent multiple connection of the same power terminal.
	  This option implies the use of the '-f' option.

     ----3333   Three layer routing option.  Use this option when per-
	  forming three layer routing (metal1, metal2 and poly).




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GLROUTE(1ICD)		     7/29/87		    GLROUTE(1ICD)



     ----VVVV   The power net name (default no VDD).

     ----GGGG   The ground net name (default no GND).

     ----ffff   Using feedthroughs if needed.  When this option is
	  specified, the netlist of the cell instances are read
	  in.  Internally connected terminals are used to shorten
	  the global wiring length.  If two nets are connected
	  via internally connected terminals, they are merged
	  into one net.

     ----wwww   Using wirethroughs if needed.  Similarly to the
	  feedthroughs, however, the internally connected termi-
	  nals do not belong to any net in the father cell.
	  Every net may use these terminals, if they can shorten
	  the wiring length.

     ----ssss   Print routing statistics after routing.

     ----aaaa   Area optimization option.  The cost function in the
	  routing channels are optimized.  It will take more CPU
	  time, because a pre-routing is carried out.

     ----oooo   New output floorplan cell name (default is the input
	  floorplan cell name).

DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
     _G_l_r_o_u_t_e is a program that globally routes interconnections
     (nets) between the terminals of the given cell and the ter-
     minals on its son cells.  The program can operate in an
     automatic mode or an interactive mode (when the -i or -g
     option is specified) It is used after the placement program
     _i_p_p and before the detailed routing program _s_e_q_u.

     The global router consists of three major parts: compaction,
     global routing and channel generation and ordering.

     At the compaction phase the blocks are moved locally in
     order to create the proper channel segment sizes.	At this
     phase the global routing routine is used as a channel esti-
     mator.  This step can be iterated several times by an user
     specified number.	In this way more accurate (realistic)
     channel structure can be generated.

     At the global routing phase, the nets are assigned to chan-
     nel segments, including the power supply nets.

     After the global routing decisions are made to group certain
     channel segments into channels and a proper channel routing
     order is generated.

     Nets with no or one terminal are ignored.	Terminals must be



2		   The Nelsis IC Design System






GLROUTE(1ICD)		     7/29/87		    GLROUTE(1ICD)



     at the boundaries of the floorplan cell and the instances,
     otherwise they are ignored.  Terminals at the corners of an
     instance are routed from the left or right side.

     The "Route_rules" file is read by the global router.  Nor-
     mally it is installed under the "~cacd/lib/process" direc-
     tory.  However, users can overrule it by putting an own
     "Route_rules" file in the working directory.

     Special net widths can be set in the "net_attr" file in the
     project directory, for example "net2 20" means that net net2
     must be routed with width 20.  Current consumption for a
     power terminal on a cell can be set in the "cell_attr" file
     in the project directory, for example "cell3 term5 25" means
     that terminal 'term5' on the cell with the cell name "cell3"
     requires 25 mA current.

EEEEXXXXAAAAMMMMPPPPLLLLEEEE
     % glroute -V vdd -G vss -o out_cell cell cir_cell
	  It means globally route the cell with floorplan cell
	  name "cell" circuit cell name "cir_cell".  The output
	  floorplan cell will be called "out_cell".  Net "vdd" is
	  the power net name and net "vss" is the ground net
	  name.

AAAAUUUUTTTTHHHHOOOORRRR
     H. Cai

FFFFIIIILLLLEEEESSSS
     Technology files:
     proj_dir/Route_rules      or
     IIIICCCCDDDDPPPPAAAATTTTHHHH/lib/process/_p_r_o_c_e_s_s__n_a_m_e/Route_rules

     proj_dir/floorplan/_c_e_l_l/info (in/output file)
     proj_dir/floorplan/_c_e_l_l/mc   (in/output file)
     proj_dir/floorplan/_c_e_l_l/term (in/output file)
     proj_dir/floorplan/_c_e_l_l/chan (in/output file)
     proj_dir/circuit/_c_e_l_l/net	  (input file)
     proj_dir/layout/_c_e_l_l/info	  (input file)
     proj_dir/layout/_c_e_l_l/term	  (input file)
     net_attr
     cell_attr

LLLLIIIIMMMMIIIITTTTAAAATTTTIIIIOOOONNNNSSSS
     At this moment only placement with slicing structures can be
     handled.  This means that the cells must be partitioned by
     straight lines.  If the placement is not a slicing struc-
     ture, it must be modified manually using interactive func-
     tions.

SSSSEEEEEEEE AAAALLLLSSSSOOOO
     H. Cai and P. Groeneveld, "Delft Placement and Routing



		   The Nelsis IC Design System			3






GLROUTE(1ICD)		     7/29/87		    GLROUTE(1ICD)



     System User's Manual", 1988, Delft University of Technology.
     gcr(1ICD), ipp(1ICD), route_rules(3ICD), sequ(1ICD).





















































4		   The Nelsis IC Design System



