====== Overlay Cell in Redhawk ======

Step to add overlay cell in RedHawk:

  - ICC: dump overlay power mesh
  - ICC: add overlay power mesh to top
  - ICC: add PG via between top and overlay cell
  - ICC: stream out overlay cell as GDSII
  - gds2def: convert overlay GDSII to DEF
  - RedHawk: use RDL_CELL in RedHawk to include overlay GDSII

===== Dump overlay power mesh =====

<code tcl>

set via_8_vdd [ get_vias -filter "via_layer==VIA8 && net_type==Power && owner_net==VDD" ]
set via_8_vss [ get_vias -filter "via_layer==VIA8 && net_type==Ground && owner_net==VSS" ]
set via_rv_vdd [ get_vias -filter "via_layer==RV && net_type==Power && owner_net==VDD" ]
set via_rv_vss [ get_vias -filter "via_layer==RV && net_type==Ground && owner_net==VSS" ]
set strap_m8_vdd [ get_net_shapes -filter "layer==M8 && net_type==Power  && owner_net==VDD" ]
set strap_m8_vss [ get_net_shapes -filter "layer==M8 && net_type==Ground && owner_net==VSS" ]
set strap_m9_vdd [ get_net_shapes -filter "layer==M9 && net_type==Power  && owner_net==VDD" ]
set strap_m9_vss [ get_net_shapes -filter "layer==M9 && net_type==Ground && owner_net==VSS" ]
set strap_ap_vdd [ get_net_shapes -filter "layer==AP && net_type==Power  && owner_net==VDD" ]
set strap_ap_vss [ get_net_shapes -filter "layer==AP && net_type==Ground && owner_net==VSS" ]

set all_pg_mesh [ add_to_collection $via_8_vss $via_8_vdd ]
set all_pg_mesh [ add_to_collection $all_pg_mesh $via_rv_vss ]
set all_pg_mesh [ add_to_collection $all_pg_mesh $via_rv_vdd ]
set all_pg_mesh [ add_to_collection $all_pg_mesh $strap_m8_vdd ]
set all_pg_mesh [ add_to_collection $all_pg_mesh $strap_m8_vss ]
set all_pg_mesh [ add_to_collection $all_pg_mesh $strap_m9_vss ]
set all_pg_mesh [ add_to_collection $all_pg_mesh $strap_m9_vdd ]
set all_pg_mesh [ add_to_collection $all_pg_mesh $strap_ap_vdd ]
set all_pg_mesh [ add_to_collection $all_pg_mesh $strap_ap_vss ]

write_route -objects $all_pg_mesh -output overlay_pg_mesh.tcl  

</code>

===== Add PG via =====
If DCAP cells are added, this stage will take a long time.

In my design, it cost about 5 hours. So don't kill it.
<code tcl>
create_preroute_vias -from_object_strap -to_object_strap -from_layer M7 -to_layer M8
create_preroute_vias -from_object_macro_io_pin -to_object_strap -from_layer M7 -to_layer M8
</code>

===== Stream Out Overlay GDSII  =====
<code tcl>
set_write_stream_options  \
  -map_layer $streamout_mw_file \
  -child_depth 10000  \
  -keep_data_type \
  -output_filling {fill} \
  -output_pin {geometry text} \
  -output_net [list text plex] \
  -output_geometry_property \
  -output_polygon_pin \
  -compressed \
  -max_name_length 100

write_stream -lib_name $mw_design_lib -format gds -cells overlay_t  overlay_t.gds.gz
</code>

===== Conver GDSII to DEF =====

gds2def Configure file:
<code>
TOP_CELL        overlay_11172011
GDS_MAP_FILE	/tools/fip40.3/lsi40nm_3.0/tsmc_cln40g/shared/apache/gds2def/lsi40_7+2.layermap
GDS_FILE	overlay_20111123.gds.gz
#LEF_FILE	zx211100_overlay_11172011.lef

VDD_NETS {
  VDD {
    VDD
  }
}

GND_NETS {
  VSS {
    VSS
  }
}

# CORE_EXTRACTION_STARTING_LAYER  	M2
# EXTRACTION_STARTING_LAYER       		M3

MEMORY_CELL	auto_detect
CHECK_TRACING	1
</code>

gds2def run command:
<code>
#! /bin/csh -f

icsub -J gds2def -qa -Ip -q priority -R "rusage[mem=20000]" -do " gds2def overlay_gds2def.cfg "
</code>


===== RDL_CELL =====
Use RDL_CELL keyword in redhawk GSR file:
<code>
RDL_CELL {
  lsifcr overlay_11172011 overlay_gds2def/zx211100_overlay_11172011.def
  #LOCATION -27 -27
  LOCATION 0 0 
  NET VDD VDD
  NET VSS VSS
}
</code>