Flows

SiliconCompiler flows are created by configuring the ['flowgraph', ...] parameters within the schema. To simplify reuse of complex flows, the project includes standardized interfaces for bundling flowgraph settings as reusable named modules.

Similar to other types of SiliconCompiler modules, flows are loaded by passing a siliconcompiler.Flow object into the use() function before a run is started. siliconcompiler.Flow objects typically use the node() and edge() functions to configure a “flowgraph” which represents a hierarchical collection of tasks to execute.

setup(chip)

A SiliconCompiler flowgraph consists of a set of connected nodes and edges, where a node is an executable tool performing some (“task”), and an edge is the connection between those tasks. The first task in the flowgraph must be named ‘import’.

flow.node(flow, 'import', <import_tool>, 'import')
flow.node(flow, <next_step>, <next_tool>, <next_task>)
flow.edge(flow, 'import', <next_step>)

In addition, the setup needs to define the compilation mode.

flow.set('option', 'mode', 'asic')

Flows that support SiliconCompiler metric functions (minimum, maximum, summary) should also set appropriate metric weights and goals for correct behavior.

for metric in ('errors','drvs','holdwns','setupwns','holdtns','setuptns'):
  flow.set('flowgraph', flow, step, index, 'goal', metric, 0)
for metric in ('cellarea', 'peakpower', 'standbypower'):
  flow.set('flowgraph', flow, step, index, 'weight', metric, 1.0)

For a complete working example, see the asicflow and fpgaflow source code.

make_docs()

The make_docs() function is used by the projects auto-doc generation. The function should include a descriptive docstring and a call to the setup function that populates the appropriate schema settings.

def make_docs(chip):
  '''
  A configurable ASIC compilation flow.
  '''

  setup(chip)
  return chip

Flow Modules

The table below shows the function interfaces for setting up Flow objects.

Function	Description	Arg	Returns	Used by	Required
setup	Flow setup function	Chip	siliconcompiler.Flow	use()	yes
make_docs	Doc generator	Chip	siliconcompiler.Flow	sphinx	no

A complete set of supported open flows can be found in Flows.