* New: In Cumulus, first versions of the ClockTree and Chip plugins.
Clock Tree plugin:
- It is strongly advised to use have 4 metal routing layers for the
tree to work. Otherwise, problems can arise with the detailed
routing (fully obstructed terminals).
- H-Tree can only be build (for now) for design with a form factor
between 0.5 an 2.
- The tree is created at the block top-level and only the leafs are
trans-hierarchically created on the instances/models. The new
cell with a clock tree, along with all it's sub-models is created
with a "_clocked" suffix.
- Leaf cells are connected through a simple Minimum Steiner Tree.
- Shorts are avoided by a systematic shift of the wires according
to their kind. No wire must pre-exist. When used as a sub-module
of "chip" the wires cannot be moved. When created on a block,
the wires can be loaded in the detailed router as manual global
router.
Chip Plugin:
- Perform the pad placement and corona creation. Replacement at
last of the clunky code from Wu Yifei.
- Relies on a Python configuration file '<design>_chip.py' with
a "chip" dictionnary.
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