[GSoC] Common Verilog Generation API and Implementation in temp-sense-gen

docs/source/common-python-api.rst

@@ -0,0 +1,90 @@
+Common Python API
+=================
+
+.. contents:: Contents
+    :local:
+
+Introduction
+------------
+
+OpenFASoC generators have a Python script that runs the generator flow (See `Generators <generators.html>`_ for more information). Many of the steps in the Python script are common across generators.
+
+A common Python module is exported in ``openfasoc/generators/common/``to reduce code duplication and simplify the creation of new generators. This module exports various functions and constants which may be used in generators.
+
+Importing
+---------
+Since the common Python module is in the ``openfasoc/generators/common/`` directory, which is a parent directory, the path to this directory must be added using ``sys.path.append()``.
+
+.. code-block:: python
+
+    import sys
+    sys.path.append(
+        # This is the relative path to the `openfasoc/generators/common/` directory.
+        os.path.join(os.path.dirname(__file__), '..', '..')
+    )
+
+Once the directory is added to the path, the exported modules can be imported using the standard Python import syntax.
+
+.. code-block:: python
+
+    from common.verilog_generation import generate_verilog
+
+See `Exported Modules`_ for a list of exported modules and their respective functions and constants.
+
+Exported Modules
+----------------
+The top level module ``common`` exports the following submodules.
+
+1. Verilog Generation (``common.verilog_generation``)
+#####################################################
+This module exports functions and constants used in the Verilog generation step. See `Temperature Sensor Generator <flow-tempsense.html#verilog-generation>`_ for more about Verilog generation.
+
+This module uses the `Mako <https://www.makotemplates.org/>`_ templating library to convert source Verilog templates into final Verilog files used in the OpenROAD flow.
+
+Functions
+^^^^^^^^^
+1. ``generate_verilog(parameters: dict, src_dir: str, out_dir: str) -> None``
+
+    Reads source Verilog files from ``src_dir`` and generates output Verilog files for synthesis in the OpenROAD flow. The source files are `Mako <https://makotemplates.org>`_ templates.
+
+    The ``parameters`` argument is a dictionary of all the parameters used in the source Verilog Mako templates. Use the ``${parameter}}`` syntax in the source files to insert parameters. For example, the number of inverters in the `Temperature Sensor Generator <flow-tempsense.html>`_ is a parameter.
+
+    This function maintains the source directory (``src_dir``) structure in the output directory (``out_dir``). i.e., source files from a subdirectory of the ``src_dir`` will be generated in a subdirectory in ``out_dir`` with the same name.
+
+    Arguments:
+        - ``src_dir`` (str): Path to the directory with the source Verilog templates. (default: ``src/``)
+        - ``out_dir`` (str): Path to the directory in which the output will be generated. (default: ``flow/design/src/``)
+        - ``parameters`` (dict): Dictionary of all the parameters used in the `Mako templates <https://makotemplates.org>`_.
+
+    Example:
+        .. code-block:: python
+
+            generate_verilog(
+                # Generates the output in flow/design/src/
+                out_dir=os.path.join('flow', 'design', 'src', 'tempsense'),
+                # Sets the parameters used in the design
+                parameters={
+                    "ninv": 6,
+                    "nhead": 3,
+                    "design_name": "tempsenseInst_error",
+                }
+            )
+
+        See the generators' Python files in ``tools/`` for more examples.
+
+    This function also appends (can be directly used in the source Verilog files) the following Mako `defs <https://docs.makotemplates.org/en/latest/defs.html>`_:
+        - ``cell(name)``
+
+            This def returns the name of a standard cell for a given platform. Currently, it only supports the sky130 platform. The naming scheme for sky130 is ``${cell_prefix}${name}${cell_suffix}``.
+
+            Here ``name`` is an argument passed to the ``cell()`` def, and ``cell_prefix`` and ``cell_suffix`` are set in the ``parameters`` argument passed to the ``generate_verilog()`` function.
+
+            For example, an inverter cell can be inserted using the syntax ``${cell('inv')}``. If the prefix is ``sky130_fd_sc_hd__`` (sky130hd) and the suffix is ``_1``, the cell will be replaced with ``sky130_fd_sc_hd__inv_1``. The same statement will be replaced with ``sky130_fd_sc_hs__inv_1`` for the sky130hs platform.
+
+            Use the constant ``COMMON_PLATFORMS_PREFIX_MAP`` for mapping a sky130 platform to its platform.
+
+Constants
+^^^^^^^^^
+1. ``COMMON_PLATFORMS_PREFIX_MAP``
+
+    This is a dictionary of common platforms (currently sky130) and their cell naming prefixes. See the ``cell()`` def in the ``generate_verilog()`` function for more information on how to use it.

docs/source/flow-tempsense.rst

@@ -45,20 +45,23 @@ Verilog generation
 Running ``make sky130hd_temp`` (temp for "temperature sensor") executes the `temp-sense-gen.py <https://github.com/idea-fasoc/OpenFASOC/blob/main/openfasoc/generators/temp-sense-gen/tools/temp-sense-gen.py>`_ script from temp-sense-gen/tools/. This file takes the input specifications from `test.json <https://github.com/idea-fasoc/OpenFASOC/blob/main/openfasoc/generators/temp-sense-gen/test.json>`_ and outputs Verilog files containing the description of the circuit.
 
 .. note::
-  temp-sense-gen.py calls other modules from temp-sense-gen/tools/ during execution. For example, `readparamgen.py <https://github.com/idea-fasoc/OpenFASOC/blob/main/openfasoc/generators/temp-sense-gen/tools/readparamgen.py>`_ is in charge of reading test.json, checking for correct user input and choosing the correct circuit elements.
+  temp-sense-gen.py calls other modules from temp-sense-gen/tools/ and generators/common/ during execution. For example, `readparamgen.py <https://github.com/idea-fasoc/OpenFASOC/blob/main/openfasoc/generators/temp-sense-gen/tools/readparamgen.py>`_ is in charge of reading test.json, checking for correct user input and choosing the correct circuit elements.
 
-The generator starts from a Verilog template of the temperature sensor circuit, located in `temp-sense-gen/src/ <https://github.com/idea-fasoc/OpenFASOC/tree/main/openfasoc/generators/temp-sense-gen/src>`_. The ``.v`` template files have lines marked with ``@@``, which are replaced according to the specifications.
+The generator starts from a Verilog template of the temperature sensor circuit, located in `temp-sense-gen/src/ <https://github.com/idea-fasoc/OpenFASOC/tree/main/openfasoc/generators/temp-sense-gen/src>`_. The ``.v`` templates follow `Mako <https://makotemplates.org>`_ syntax. For example, ``${param}`` is replaced with the value of the parameter ``param``.
 
-Example: `counter_generic.v line 31 <https://github.com/idea-fasoc/OpenFASOC/blob/main/openfasoc/generators/temp-sense-gen/src/counter_generic.v#L31>`_ is replaced during Verilog generation.
+See `Common Python API <common-python-api.html#verilog-generation-common-verilog-generation>`_ for more information.
+
+Example: In `counter.v line 31 <https://github.com/idea-fasoc/OpenFASOC/blob/main/openfasoc/generators/temp-sense-gen/src/counter.v#L32>`_, ``${cell('buf')}`` with the buffer cell which is ``sky130_fd_sc_hd__buf_1`` for sky130hd.
 
 .. code-block:: verilog
-  :emphasize-lines: 3
+  :emphasize-lines: 4
   :linenos:
   :lineno-start: 29
 
   assign done_sens = WAKE_pre &&  doneb;
-	assign done_ref = WAKE && doneb;
-  @@ @np Buf_DONE(.A(done_pre), .nbout(DONE));
+  assign done_ref = WAKE && doneb;
+
+  ${cell('buf')} Buf_DONE(.A(done_pre), .X(DONE));
 
   always @ (*) begin
     case (done_pre)
@@ -87,15 +90,15 @@ OpenROAD Flow takes a design from the temp-sense-gen/flow/design/ directory and
       └── design
           ├── sky130hd
           │   └── tempsense
-          │       ├── config.mk             <--
+          │       ├── config.mk          <--
           │       └── constraint.sdc
           └── src
               └── tempsense
-                  ├── counter.v             <--
-                  ├── TEMP_ANALOG_hv.nl.v   <--
-                  ├── TEMP_ANALOG_lv.nl.v   <--
-                  ├── TEMP_AUTO_def.v       <--
-                  └── tempsenseInst_error.v <--
+                  ├── counter.v          <--
+                  ├── TEMP_ANALOG_hv.v   <--
+                  ├── TEMP_ANALOG_lv.v   <--
+                  ├── TEMP_AUTO_def.v    <--
+                  └── tempsenseInst.v    <--
 
 For more information on OpenROAD Flow, check their `docs <https://openroad.readthedocs.io/en/latest/user/GettingStarted.html>`_.
 

docs/source/index.rst

@@ -32,6 +32,7 @@ If you are willing to contribute, please visit the :doc:`developers-guide` secti
 
    getting-started
    generators
+   common-python-api
    tapeouts
    examples
    developers-guide

openfasoc/generators/common/__init__.py

@@ -0,0 +1,10 @@
+"""A common module used in OpenFASOC generators.
+
+This module exports functions used in OpenFASOC generators. The following submodules and functions are exported.
+
+- `common.verilog_generation`
+	1. `generate_verilog(parameters: dict, src_dir: str, out_dir: str) -> None`: Used to generate synthesizable Verilog files (for OpenROAD flow) from source Mako-based Verilog templates.
+	2. `COMMON_PLATFORMS_PREFIX_MAP` (dict): This is a dictionary of common platforms (currently sky130) and their cell naming prefixes.
+
+See individual function documentation for more information on a particular function.
+"""

openfasoc/generators/common/verilog_generation.py

@@ -0,0 +1,102 @@
+from mako.template import Template
+from os import path, makedirs, listdir
+
+# TODO: Find a better way to import common used defs in the future.
+__COMMON_MAKO_DEFS = '''
+<%def name="cell(name)">${cell_prefix}${name}${cell_suffix}</%def>
+'''
+
+def _mako_defs_preprocessor(input: str) -> str:
+	"""A Mako preprocessor that appens commonly used defs to the template.
+
+	Mako templates have a preprocessor argument. See https://docs.makotemplates.org/en/latest/usage.html#mako.template.Template.params.preprocessor.
+	This preprocessor adds defs commonly used in Verilog files to the template.
+	TODO: Find a better way to import common used defs in the future.
+	"""
+	return __COMMON_MAKO_DEFS + input
+
+def _generate_file(input_path: str, output_path: str, parameters: dict) -> None:
+	"""Generates a single output Verilog file from its Mako template.
+
+	Arguments:
+	- `input_path` (str): Path to the input file (Mako template) with the extension.
+	- `output_path` (str): Path to the output file location with the extension.
+	- `parameters` (dict): Dictionary of all the parameters used in the Mako template.
+	"""
+
+	# TODO: Find a better way to import common used defs in the future.
+	template = Template(filename=input_path, preprocessor=_mako_defs_preprocessor)
+
+	out_file = open(output_path, "w")
+	out_file.write(template.render(**parameters))
+
+def _generate_subdirectory(src_dir: str, out_dir: str, parameters: dict) -> None:
+	"""Generates the output Verilog files of a single subdirectory of Mako templates.
+
+	Reads Mako templates from a subdirectory (`src_dir`), generates the output files in the output directory (`out_dir`), and maintains the directory structure. i.e., templates from a subdirectory of the `src_dir` will be generated in a subdirectory in `out_dir` with the same name.
+
+	This function recursively calls itself for subdirectories.
+
+	Arguments:
+	- `src_dir` (str): Path to the source directory with Mako templates.
+	- `out_dir` (str): Path to the output directory.
+	- `parameters` (dict): Dictionary of all the parameters used in the Mako template.
+	"""
+	# generate the output directory if it doesn't exist
+	if not path.exists(out_dir):
+		makedirs(out_dir)
+
+	for filename in listdir(src_dir):
+		input_filepath = path.join(src_dir, filename)
+		output_filepath = path.join(out_dir, filename)
+
+		if path.isdir(input_filepath):
+			# if the path is a subdirectory, recursively call the function
+			_generate_subdirectory(
+				input_filepath,
+				output_filepath,
+				parameters
+			)
+		else:
+			# if the path is a fine, generate the output
+			_generate_file(
+				input_filepath,
+				output_filepath,
+				parameters
+			)
+
+def generate_verilog(
+	parameters: dict,
+	src_dir: str = "src",
+	out_dir: str = path.join("flow", "design", "src")
+) -> None:
+	"""Generates output Verilog files from source Mako templates.
+
+	Reads source Verilog files from `src_dir` and generates output Verilog files for synthesis in the OpenROAD flow.
+	The source files are Mako templates. See https://makotemplates.org for syntax and documentation.
+
+	This function maintains the source directory (`src_dir`) structure in the output directory (`out_dir`). i.e., source files from a subdirectory of the `src_dir` will be generated in a subdirectory in `out_dir` with the same name.
+
+	Arguments:
+	- `parameters` (dict): Dictionary of all the parameters used in the Mako templates. See https://makotemplates.org for documentation.
+	- `src_dir` (str): Path to the directory with the source Verilog templates.
+	- `out_dir` (str): Path to the directory in which the output will be generated.
+	"""
+	_generate_subdirectory(src_dir, out_dir, parameters)
+
+# A dictionary of commonly used platforms and the prefix used in their cell naming
+# Currently includes only sky130 platform prefixes
+COMMON_PLATFORMS_PREFIX_MAP = {
+	"sky130hd": "sky130_fd_sc_hd__",
+	"sky130hs": "sky130_fd_sc_hs__",
+	"sky130hvl": "sky130_fd_sc_hvl__",
+	"sky130osu12Ths": "sky130_osu_sc_12T_hs__",
+	"sky130osu12Tms": "sky130_osu_sc_12T_ms__",
+	"sky130osu12Tls": "sky130_osu_sc_12T_ls__",
+	"sky130osu15Ths": "sky130_osu_sc_15T_hs__",
+	"sky130osu15Tms": "sky130_osu_sc_15T_ms__",
+	"sky130osu15Tls": "sky130_osu_sc_15T_ls__",
+	"sky130osu18Ths": "sky130_osu_sc_18T_hs__",
+	"sky130osu18Tms": "sky130_osu_sc_18T_ms__",
+	"sky130osu18Tls": "sky130_osu_sc_18T_ls__"
+}

openfasoc/generators/temp-sense-gen/Makefile

@@ -69,6 +69,7 @@ clean:
 	rm -f error_within_x.csv golden_error_opt.csv search_result.csv
 	rm -rf work
 	rm -rf tools/*.pyc tools/__pycache__/
+	rm -rf flow/design/src/tempsense
 	cd flow && make clean_all
 	cd simulations && rm -rf run
 

openfasoc/generators/temp-sense-gen/flow/design/src/.gitignore

@@ -0,0 +1 @@
+tempsense/

openfasoc/generators/temp-sense-gen/src/TEMP_ANALOG_hv.v

@@ -26,8 +26,11 @@ counter async_counter_0(
 );
 
 (* keep *)
-@@ @nf a_header_@nh(.VIN(VIN));
-SLC
-@@ @no a_buffer_0 (.A(lc_0), .nbout(lc_out));
+% for i in range(nhead):
+${header_cell} a_header_${i}(.VIN(VIN));
+% endfor
+// SLC
+${slc_cell} a_lc_0(.IN(out), .INB(outb), .VOUT(lc_0));
+${cell('buf')} a_buffer_0 (.A(lc_0), .X(lc_out));
 
 endmodule

openfasoc/generators/temp-sense-gen/src/TEMP_ANALOG_lv.v

@@ -3,16 +3,25 @@ module TEMP_ANALOG_lv (EN, OUT, OUTB);
 // inout in_vin;
  output OUT, OUTB;
  wire  n;
-@@ wire n@nn;
+
+% for i in range(ninv + 1):
+wire n${i + 1};
+% endfor
+
 wire nx1, nx2, nx3, nb1, nb2;
-@@ @na a_nand_0 ( .A(EN), .B(n@n0), .Y(n1));
-@@ @nb a_inv_@ni ( .A(n@n1), .Y(n@n2));
-@@ @ng a_inv_m1 ( .A(n@n3), .Y(nx1));
-@@ @nk a_inv_m2 ( .A(n@n4), .Y(nx2));
-@@ @nm a_inv_m3 ( .A(nx2), .Y(nx3));
-@@ @np a_buf_3 ( .A(nx3), .nbout(nb2));
-@@ @nc a_buf_0 ( .A(nx1), .nbout(nb1));
-@@ @nd a_buf_1 ( .A(nb1), .nbout(OUT));
-@@ @ne a_buf_2 ( .A(nb2), .nbout(OUTB));
+
+${cell('nand2')} a_nand_0 ( .A(EN), .B(n${ninv + 1}), .Y(n1));
+
+% for i in range(ninv):
+${cell('inv')} a_inv_${i} ( .A(n${i + 1}), .Y(n${i + 2}));
+% endfor
+
+${cell('inv')} a_inv_m1 ( .A(n${ninv + 1}), .Y(nx1));
+${cell('inv')} a_inv_m2 ( .A(n${ninv + 1}), .Y(nx2));
+${cell('inv')} a_inv_m3 ( .A(nx2), .Y(nx3));
+${cell('buf')} a_buf_3 ( .A(nx3), .X(nb2));
+${cell('buf')} a_buf_0 ( .A(nx1), .X(nb1));
+${cell('buf')} a_buf_1 ( .A(nb1), .X(OUT));
+${cell('buf')} a_buf_2 ( .A(nb2), .X(OUTB));
 
 endmodule

openfasoc/generators/temp-sense-gen/src/counter_generic.v → openfasoc/generators/temp-sense-gen/src/counter.v

@@ -28,7 +28,8 @@ module counter#
 	assign done_ref = WAKE && doneb;
 //	BUFH_X4M_A9TR	Buf_DONE(.A(done_pre), .Y(DONE));
 //	BUF_X0P4N_A10P5PP84TR_C14	Buf_DONE(.A(done_pre), .Y(DONE));
-@@ @np Buf_DONE(.A(done_pre), .nbout(DONE));
+
+	${cell('buf')} Buf_DONE(.A(done_pre), .X(DONE));
 	//assign RESET_CLK_REF = ~q1;
 
 	always @ (*) begin

openfasoc/generators/temp-sense-gen/src/tempsenseInst.v

@@ -1,4 +1,4 @@
-module tempsenseInst_error
+module ${design_name}
 (
 	input CLK_REF,
 	input RESET_COUNTERn,