gilgamsh / lefdef-python

Python iterface for Cadence LEF/DEF parser.

LEFDEF Python

This repository provides a Python interface to parse LEF (Library Exchange Format) and DEF (Design Exchange Format) files.

Install

You can install library using pip

pip install lefdef

Usage

To use the LEF reader, you can follow the example provided in the test.py file:

from lefdef import C_LefReader
from lefdef import C_DefReader

lef_reader = C_LefReader()
_lef = lef_reader.read("/path/to/lef/file.lef")
_lef.print()

def_reader = C_DefReader()
_def = def_reader.read("/path/to/def/file.def")
_def.print()

It will read and print all information that have been read.

Data structure

• LEF/DEF Reader: A Python classes C_LefReader and C_DefReader that allows reading LEF/DEF files and extracting the design data.

• LEF Data Structures:

  • C_Lef - top level container of lef file

    • c_macros - a list of all macros in lef file
    • c_num_macros - the number of macros in lef (use this to iterate over c_macros)

  • C_Lef_Macro - container for MACRO statement

    • c_name - the name of macro
    • c_class - the value of CLASS statement
    • c_source - the value of SOURCE statement
    • c_site_name - the value of SITE statemen
    • c_origin_x - the postion of macro by x axis
    • c_origin_y -the postion of macro by y axis
    • c_size_x -the width of macro
    • c_size_y - the height of macro
    • c_foreign_name - the name of foreign
    • c_foreign_x - the foreing's position by x axis
    • c_foreign_y - the foreing's position by y axis
    • c_pins - a list of macro's pins
    • c_num_pins - the number of pins (use this to iterate over c_pins)

  • C_Lef_Obstruction - container for OBS statement

    • c_rects - the obstruction's geometry
    • c_num_rects - the number of rectangles in obstruction (use this to iterate over c_rects)

  • C_Lef_Pin - container for PIN statement

    • c_name - the pin's name
    • c_direction - the value of DIRECTION statement
    • c_use - the value of USE statement
    • c_shape - the value of SHAPE statement
    • c_ports - a list pf pin's ports
    • c_num_ports - the number of porst in pin (use this to iterate over c_ports)

  • C_Lef_Port - container for PORT statement

    • c_rects - the port's geometry
    • c_num_rects - the number of rectangles in port (use this to iterate over c_rects)

  • C_Lef_Rect - container for LAYER statement

    • c_layer - the layer name
    • c_xl - the x value of lef top corner
    • c_yl - the y value of lef top corner
    • c_xh - the x value of right bottom corner
    • c_yh - the y value of right bottom corner

LEF Example

from lefdef import C_LefReader

lef_reader = C_LefReader()
lef = lef_reader.read("/path/to/lef/file.lef")

for i in range(lef.c_num_macros):
    class_ = lef.c_macros[i].c_class
    source = lef.c_macros[i].c_source
    site_name = lef.c_macros[i].c_site_name
    origin_x = lef.c_macros[i].c_origin_x
    origin_y = lef.c_macros[i].c_origin_y
    foreign_name = lef.c_macros[i].c_foreign_name
    foreign_x = lef.c_macros[i].c_foreign_x
    foreign_y = lef.c_macros[i].c_foreign_y
    foreign_orient = lef.c_macros[i].c_foreign_orient
    pins = lef.c_macros[i].c_pins
    obs = lef.c_macros[i].c_obs

    # Access pins
    for j in range(lef.c_macros[i].c_num_pins):
        name = pins[j].c_name
        direction = pins[j].c_direction
        use = pins[j].c_use
        shape = pins[j].c_shape
        ports = pins[j].c_ports

        # Access pins's ports
        for k in range(pins[j].c_num_ports):
            rects = ports[k].c_rects

            # Access ports's rectangles
            for l in range(ports[k].c_num_rects):
                layer = rects[l].c_layer
                xl = rects[l].c_xl
                yl = rects[l].c_yl
                xh = rects[l].c_xh
                yh = rects[l].c_yh

    # Access obs's rectangles
    for j in range(obs.c_num_rects):
        layer = obs.rects[j].c_layer
        xl = obs.rects[j].c_xl
        yl = obs.rects[j].c_yl
        xh = obs.rects[j].c_xh
        yh = obs.rects[j].c_yh

• DEF Data Structures:

  • C_Def - top level container of def file

    • c_die_area_width - a list of x points of die area
    • c_die_area_height - a list of y points of die arae
    • c_num_points - the number of points of die arae (use this to iterate over c_die_area_width and c_die_area_height)
    • c_g_cell_grid_x - a list of gCellGrid by x axis
    • c_num_g_cell_grid_x - the number of gCellGrid by x axis (use this to iterate over c_num_g_cell_grid_x)
    • c_g_cell_grid_y - a list of gCellGrid by y axis
    • c_num_g_cell_grid_y - the number of gCellGrid by y axis (use this to iterate over c_num_g_cell_grid_x)
    • c_pins - a list of def's pins
    • c_num_pins - the number of pins (use this to iterate over c_pins)
    • c_nets - a list of def's nets
    • c_num_nets - the number of nets (use this to iterate over c_nets)
    • c_rows - a list of def's rows
    • c_num_rows - the number of rows (use this to iterate over c_rows)
    • c_tracks_x - a list of def's tracks by x axis
    • c_num_tracks_x - the number of tracks by x axis (use this to iterate over c_tracks_x)
    • c_tracks_y - a list of def's tracks by y axis
    • c_num_tracks_y- the number of tracks by y axis (use this to iterate over c_tracks_y)

  • C_Def_Net - container for net in NETS statement

    • c_name - the net's name
    • c_instances - a list of names of components in this net
    • c_pins - a list of names of pins in this net, list length is equal to c_instances's length
    • c_num_pins - the number of pins in this net

  • C_Def_Pin - container of pin in PINS statement

    • c_name - the pin name
    • c_net - the pin's net name
    • c_use - the value of USE statement
    • c_status - the value of STATUS statement
    • c_direction - the value of DIRECTOIN statement
    • c_orient - the pin's orientation
    • c_rects - the pin's geometry
    • c_num_rects - a number of rectangles (use this to iterate over c_rects)
    • c_ports - a list of pin's ports
    • c_num_ports - a number of ports (use this to iterate over c_ports)

  • C_Def_Component - container of standart cell in COMPONENTS statement

    • c_id - the component name in the design
    • c_name - the name of a model defined in the library
    • c_status - the value of STATUS statement
    • c_source - the value of SOURCE statement
    • c_oirent - the component's orientation
    • c_x - the location by x axis
    • c_y - the location by y axis

  • C_Def_GCellGrid - container of GCELLGRID statement

    • c_offest - the location of the first row/column
    • c_num - the number of rows/columns
    • c_step - the spacing between rows/columns

  • C_Def_Track - container of TRACK statement

    • c_layer - the routing layer used for the tracks
    • c_offest - location of the first track (column/row)
    • c_num - the number of tracks to create for the grid by x or y axis
    • c_step - he spacing between the tracks (column/row)

  • C_Def_Row - container of ROW statement

    • c_name - the row's name
    • c_macro - the value of SITE statement
    • c_x - the location of the first site in the row by x axsis
    • c_y - the location of the first site in the row by y axsis
    • c_num_x - a repeating set of sites that create the row by x axsis
    • c_num_y - a repeating set of sites that create the row by y axsis
    • c_step_x - the spacing between sites in vertical rows
    • c_step_y - the spacing between sites in horizontal rows

  • C_Def_Port - container for PORT statement

    • c_rects - the port's geometry
    • c_num_rects - the number of rectangles in port (use this to iterate over c_rects)

  • C_Lef_Rect - container for LAYER statement

    • c_layer - the layer name
    • c_xl - the x value of lef top corner
    • c_yl - the y value of lef top corner
    • c_xh - the x value of right bottom corner
    • c_yh - the y value of right bottom corner

DEF Example

from lefdef import C_DefReader

def_reader = C_DefReader()
_def = def_reader.read("/path/to/def/file.def")

die_area_width = _def.c_die_area_width
die_area_height = _def.c_die_area_height
g_cell_grid_x = _def.c_g_cell_grid_x
num_g_cell_grid_x = _def.c_num_g_cell_grid_x
g_cell_grid_y = _def.c_g_cell_grid_y
components = _def.c_components
pins = _def.c_pins
nets = _def.c_nets
rows = _def.c_rows
tracks_x = _def.c_tracks_x
tracks_y = _def.c_tracks_y

# Access gCellGrid by x axis
for i in range(_def.c_num_g_cell_grid_x):
    offset_x = g_cell_grid_x[i].c_offset
    num_x = g_cell_grid_x[i].c_num
    step_y = g_cell_grid_x[i].c_step

# Access gCellGrid by y axis
for i in range(_def.c_num_g_cell_grid_y):
    offset_y = g_cell_grid_y[i].c_offset
    num_y = g_cell_grid_y[i].c_num
    step_y = g_cell_grid_y[i].c_step

# Access components
for i in range(_def.c_num_components):
    id = components[i].c_id
    name = components[i].c_name
    status = components[i].c_status
    source = components[i].c_source
    orient = components[i].c_orient
    x = components[i].c_x
    y = components[i].c_y

# Access pins
for i in range(_def.c_num_pins):
    name = pins[i].c_name
    net = pins[i].c_net
    use = pins[i].c_use
    status = pins[i].c_status
    direction = pins[i].c_direction
    orient = pins[i].c_orient
    x = pins[i].c_x
    y = pins[i].c_y
    rects = pins[i].c_rects
    ports = pins[i].c_ports

    # Access pin's rectangles
    for j in range(pins[i].c_num_rects):
        layer = rects[j].c_layer
        xl = rects[j].c_xl
        yl = rects[j].c_yl
        xh = rects[j].c_xh
        yh = rects[j].c_yh

    # Access pin's ports
    for j in range(pins[i].c_num_ports):
        rects = ports[j].c_rects

        # Access ports's rectangles
        for k in range(ports[j].c_num_rects):
            layer = rects[k].c_layer
            xl = rects[k].c_xl
            yl = rects[k].c_yl
            xh = rects[k].c_xh
            yh = rects[k].c_yh

# Access nets
for i in range(_def.c_num_nets):
    name = nets[i].c_name

    for j in range(nets[i].c_num_pins):
        instance = nets[i].c_instances[j]
        pins = nets[i].c_pins[j]

# Access rows
for i in range(_def.c_num_rows):
    name = rows[i].c_name
    macro = rows[i].c_macro
    x = rows[i].c_x
    y = rows[i].c_y
    num_x = rows[i].c_num_x
    num_y = rows[i].c_num_y
    step_x = rows[i].c_step_x
    step_y = rows[i].c_step_y

# Access tracks by x axis
for i in range(_def.c_num_tracks_x):
    layer = tracks_x[i].c_layer
    offset = tracks_x[i].c_offset
    num = tracks_x[i].c_num
    step = tracks_x[i].c_step

# Access tracks by y axis
for i in range(_def.c_num_tracks_y):
    layer = tracks_y[i].c_layer
    offset = tracks_y[i].c_offset
    num = tracks_y[i].c_num
    step = tracks_y[i].c_step

Contributing

We welcome contributions from the community! Whether it's a bug report, new feature, or a correction, your help is greatly appreciated. Here's how you can contribute:

1. Fork the Repository: Start by forking the lefdef-python repository.

2. Clone Your Fork:

   git clone https://github.com/YOUR_USERNAME/lefdef-python.git
   cd lefdef-python

3. Create a New Branch:

   git checkout -b feature/your-feature-name

4. Make Your Changes: Implement your changes, enhancements, or bug fixes.

5. Commit and Push:

   git add .
   git commit -m "Your detailed commit message"
   git push origin feature/your-feature-name

6. Open a Pull Request: Go to the lefdef-python repository on GitHub and click on the "New Pull Request" button. Select your fork and the branch you created to submit a pull request.

7. Wait for Review: Once your pull request is submitted, maintainers will review your changes. Address any feedback to get your changes merged.

Reporting Bugs

If you find a bug or an issue, please create a new issue in the issue tracker describing the problem and providing steps to reproduce it.