How to create manual routes

[titan73]

Are there commands to create manual routes? Typically to route critical net or power/ground nets of a macro.

[maliberty]

Not really. There are the raw odb APIs. There is a very basic sroute for power nets though typically macro power is handled by pdn.

[titan73]

So I should use the API from?
https://github.com/The-OpenROAD-Project/OpenROAD/blob/master/src/odb/include/odb/db.h
There are dbWire, dbSwire and SBox. What is the difference between dbWire and dbSWire?

There is also dbWireEncoder in https://github.com/The-OpenROAD-Project/OpenROAD/blob/master/src/odb/include/odb/dbWireCodec.h.
There are examples in the test. It works but it does not seem we can change the wire width.
Also it's based on dbWire not dbSWire.

[maliberty]

Wire vs SWire is the same distinction as in DEF NET vs SPECIALNET.

[titan73]

Do you mean sroute from pdn?

[maliberty]

yes

[titan73]

Ok thanks.

It seems it's possible to set the width in the wire encoder with a dbTechLayerRule* argument. How can I create one and set its width?

[titan73]

odb::dbTechLayerRule_create $db does not work:

[ERROR GUI-0070] Wrong number of arguments :odb::dbTechLayerRule_create rule layer  argument 2
Wrong number of arguments :odb::dbTechLayerRule_create rule layer  argument 2
    while executing
"odb::dbTechLayerRule_create $db"

The constructor is:
_dbTechLayerRule(_dbDatabase*);

[titan73]

Actually odb::dbTechLayerRule_create requires 2 args: rule and layer. I doesn't work though. I tried this code:

set db      [ord::get_db]
set block   [ord::get_db_block]
set tech    [ord::get_db_tech]
set metal4B [$tech findLayer metal4B]
create_ndr -name WIDTH -width {metal4B 3}
set ndr [$block findNonDefaultRule WIDTH]
set tlr [odb::dbTechLayerRule_create $ndr $metal4B]

but I get NULL:

>>> set tlr [odb::dbTechLayerRule_create $ndr $metal4B]
... 
NULL

Is that normal?

[titan73]

Not clear what it doesn't work but I saw in odb.tcl:

  set rule [$ndr getLayerRule $layer]
  if { $rule == "NULL" } {
    set rule [odb::dbTechLayerRule_create $ndr $layer]
  }

and $ndr getLayerRule $metal4B works.

Here are the code I use:

set db      [ord::get_db]
set block   [ord::get_db_block]
set tech    [ord::get_db_tech]
set metal4B [$tech findLayer metal4B]
set net     [$block findNet GNDA_FTP]
set wire    [odb::dbWire_create $net]

create_ndr -name WIDTH -width {metal4B 3}
set ndr [$block findNonDefaultRule WIDTH]
set width [$ndr getLayerRule $metal4B]

set wire_encoder [odb::dbWireEncoder]
$wire_encoder begin $wire
$wire_encoder newPath $metal4B "ROUTED" $width
$wire_encoder addPoint 200000 200000
$wire_encoder addPoint 150000 200000
$wire_encoder addPoint 150000 150000
$wire_encoder end

However this works only for the preferred direction (vertical):

Is there a way to have the rule works on both directions?