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updates to README

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nayiri-k
2022-09-14 17:36:18 -07:00
parent 237146577e
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docs/VLSI/Sky130-OpenROAD-Tutorial.rst
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@@ -89,8 +89,15 @@ First, set ``technology.sky130.<sky130A, sky130_nda, openram_lib>`` to the absol
for details about the PDK setup.
example-openroad.yml
^^^^^^^^^^^^^^^^^^^^
This contains the Hammer configuration for the OpenROAD tool flow.
It selects tools for synthesis (Yosys), place and route (OpenROAD), DRC (Magic), and LVS (NetGen).
For the remaining commands, we will need to specify this file as the tool configuration to hammer via the ``TOOLS_CONF`` Makefile variable.
Generating SRAMs
----------------
^^^^^^^^^^^^^^^^
To map the generic memory macros in the generarted Verilog to the SRAMs in your technology process, run the following command:
.. code-block:: shell
@@ -98,7 +105,7 @@ To map the generic memory macros in the generarted Verilog to the SRAMs in your
make srams tech_name=sky130 CONFIG=TinyRocketConfig
Generating Verilog
------------------
^^^^^^^^^^^^^^^^^^
To elaborate the ``TinyRocketConfig`` from Chisel to Verilog, run:
.. code-block:: shell
@@ -108,7 +115,7 @@ To elaborate the ``TinyRocketConfig`` from Chisel to Verilog, run:
The ``CONFIG=TinyRocketConfig`` selects the target generator config in the same manner as the rest of the Chipyard framework. This elaborates a stripped-down Rocket Chip in the interest of minimizing tool runtime. The resulting verilog is located in ``./generated-src/chipyard.TestHarness.TinyRocketConfig/chipyard.TestHarness.TinyRocketConfig.top.v``.
Note that in the generated Verilog, there are generic memory macros for the various memory components (dcache, icache, tag array, PTW).
This is the same Verilog that is generated for RTL simulations in the ``~chipyard/sims/verilator`` directory, see ` :ref:`Simulation/Software-RTL-Simulation:sw-rtl-sim-intro` for directions on how to run these simulations.
This is the same Verilog that is generated for RTL simulations in the ``~chipyard/sims/verilator`` directory, see :ref:`Simulation/Software-RTL-Simulation:Software RTL Simulation` for directions on how to run these simulations.
Building the Design
^^^^^^^^^^^^^^^^^^^
@@ -116,14 +123,11 @@ To set up all prerequisites for the build system to push the design and SRAM mac
.. code-block:: shell
make buildfile tech_name=sky130 CONFIG=TinyRocketConfig
make buildfile tech_name=sky130 TOOLS_CONF=example-openroad.yml CONFIG=TinyRocketConfig
For the curious, ``make buildfile`` generates a set of Make targets in ``build/hammer.d``. It needs to be re-run if environment variables are changed. It is recommended that you edit these variables directly in the Makefile rather than exporting them to your shell environment.
example-openroad.yml
^^^^^^^^^^^^^^^^^^^^
This contains the Hammer configuration for the OpenROAD tool flow. It selects tools for the SRAM "compiler" (already specified in ``example-sky130.yml``), synthesis (Yosys), place and route (OpenROAD), DRC (Magic), and LVS (NetGen). For the remaining commands, we will need to specify this file as the tool configuration to hammer via the ``TOOLS_CONF`` Makefile variable.
The command ``make buildfile`` generates a set of Make targets in ``build/hammer.d``.
It needs to be re-run if environment variables are changed.
It is recommended that you edit these variables directly in the Makefile rather than exporting them to your shell environment.
Synthesis
@@ -131,7 +135,7 @@ Synthesis
.. code-block:: shell
make syn tech_name=sky130 TOOLS_CONF=example-openroad.yml CONFIG=TinyRocketConfig
make syn tech_name=sky130 CONFIG=TinyRocketConfig
Post-synthesis logs and collateral are in ``build/syn-rundir``.
@@ -141,7 +145,7 @@ Place-and-Route
^^^^^^^^^^^^^^^
.. code-block:: shell
make par tech_name=sky130 TOOLS_CONF=example-openroad.yml CONFIG=TinyRocketConfig
make par tech_name=sky130 CONFIG=TinyRocketConfig
After completion, the final database can be opened in an interactive OpenROAD session.
@@ -167,8 +171,38 @@ To run DRC & LVS:
.. code-block:: shell
make drc tech_name=sky130 TOOLS_CONF=example-openroad.yml CONFIG=TinyRocketConfig
make lvs tech_name=sky130 TOOLS_CONF=example-openroad.yml CONFIG=TinyRocketConfig
make drc tech_name=sky130 CONFIG=TinyRocketConfig
make lvs tech_name=sky130 CONFIG=TinyRocketConfig
Some DRC errors are expected from this PDK, especially with regards to the SRAMs, as explained in the
`Sky130 Hammer plugin README <https://github.com/ucb-bar/hammer/blob/master/src/hammer-vlsi/technology/sky130/README.md>`__.
VLSI Flow Control
-----------------
The Hammer tool plugins for each action (e.g. ``syn``, ``par``) support multiple steps (e.g. ``macro_placement``, ``global_route``).
Hammer saves the design database before and after each step in ``build/par-rundir/<pre or post>_<step name>``.
The Hammer flow supports being able to start/stop before/after any of these steps.
See the `Hammer documentation on Flow Control <https://docs.hammer-eda.org/en/latest/Hammer-Use/Flow-Control.html>`__ for a full list and description of the options.
The ``Makefile`` in the ``vlsi`` directory passes this extra information via the ``HAMMER_EXTRA_ARGS`` variable.
This variable can also be used to specify additional YAML configurations that may have changed or been omitted from the inital build.
The below examples use the ``redo-par`` Make target to re-run only place-and-route. ``redo-`` may be prepended to any of the VLSI flow actions to re-run only that action.
.. code-block:: shell
# the following two statements are equivalent because the
# extraction step immediately precedes the write_design step
make redo-par HAMMER_EXTRA_ARGS="--start_after_step extraction"
make redo-par HAMMER_EXTRA_ARGS="--start_before_step write_design"
# example of re-running only floorplanning to test out a new floorplan configuration
make redo-par HAMMER_EXTRA_ARGS="--only_step floorplan_design -p example-sky130.yml"
Documentation
-------------
For more information about Hammer's underlying implementation, visit the `Hammer documentation website <https://docs.hammer-eda.org/en/latest/index.html>`__.
For details about the plugins used in this tutorial, check out the `OpenROAD tool plugin repo + README <https://github.com/ucb-bar/hammer/tree/master/src/hammer-vlsi/par/openroad>`__
and `Sky130 tech plugin repo + README <https://github.com/ucb-bar/hammer/tree/master/src/hammer-vlsi/technology/sky130>`__.