* New: In Etesian::Configuration add new parameters for antenna
effect management:
* "etesian.diodeName" : the name of the diode cell.
* "etesian.antennaMaxwl" : maximum length above which antenna
effect can occur. Must be the maximum for all the normal
routing layers.
* "etesian.antennaInsertThreshold" : during the placement steps,
threshold for linear disruption at which we will look for
the RSMT and insert diodes.
* New: In EtesianEngine::antennaProtect(), at a designated point
in the placement iteratives step, when the spreading starts to
be significant enough estimate the RSMT length and add a diode
if need be. The diode will be put side by side with the driver
cell. This is done by enlarging the driver cell of the diode
width.
* New: In EtesianEngine::_updatePlacement(), in the final stage,
modify the netlist to connect the diode. The diode will be
put on the side of the cell closest to the driver. This may
alow to make the connexion directly in METAL1 in the future.
* Change: In etesian/Placement.cpp, make the whole placement
structure a persistent attribute of the EtesianEngine so
it can be used afterwards.
Add a post-placement diode insertion feature. Finally
unused as they are added on the fly during placement.
In the Area, add data about the diode tie in the TieLut.
* Change: Add EtesianEnginea::clearColoquinte(), to keep the
post-placement structure while purging the Coloquinte one.
* Change: In cumulus/plugins.block.block, keep the Etesian engine
until the whole P&R is done, so we potentially can exploit
the post-placement datas.
* Bug: In cumulus/plugins.chip.power.GoCb(), for the METAL1 power
and ground wires coming from the standard cell, it was assumed
they where made of Horizontal segments, this is not the case
in FlexLib... So force to consider the plane as Horizontal when
we are processing that plane.
Better solution should be to use Horizontals...