werni2a / openallegroparser Goto Github PK

In OrCAD we can export the design into a XML which directly shows us which information is stored in the binary file and probably also how it is stored. Maybe Extracta can do the same for layouts. A short introduction how to use the tool is provided in [1]. Further, [1] states that there is a Linux version of the tool. Can this one be downloaded somewhere or why would Cadence distribute a Linux tool on an Windows machine?

[1] BoardSurfers: Translating Allegro Database to Readable Format Using 'Extracta'

I used the board linked in the following issue to decode some board informations: OpenBoardView/OpenBoardView#126

In my case, I started with the lowest level of information (e.g. known tracks), thus I hardcoded "known" positions in the file to extract records as I think they might fit. I think for such binary-blobs that's the better approach, as it allows you to expand your knowlege step-wise. If you know how a record look like you can find the first one, and then the index to that record,..

This is just a dump of information I decoded some months ago, hope it helps 😃

Main Findings

• The file is little-endian
  • degrees are stored as 4 byte little endian integers in thousands of degrees (e.g. 180° = 180000)
  • coordinates are stored as 4 byte little endian integers, first comes x and then y. Sorry, I forgot in which unit they were (but you should find this out using the kaitai file and a board-viewer)
• I found some general "magic-byte" sequence which seemed to be the same on all files I looked on so far

Kaitai File

meta:
  id: allegro
  title: Allegro board file
  file-extension: brd
  endian: le
  encoding: UTF-8

# Findings (27.04.2021)
# Degree:
#  le 4 byte 180° = 180000
# Position x|y
#  le 4 byte | le 4 byte
# How found out: search for 180, 1800, 18000 until a high number of matches is found

# those numbers are the same on all allegro files I saw so far:
seq:
  - size: 3
  - id: magic
    contents: [0x00, 0x03, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x09, 0x00, 0x00, 0x00]
  - size: 44
  - id: zeroes1
    contents: [0x00, 0x00, 0x00, 0x00]
  - size: 60
  - id: zeroes2
    contents: [0x00, 0x00, 0x00, 0x00]
  - size: 36
  - id: zeroes3
    contents: [0x00, 0x00, 0x00, 0x00]
  - size: 28
  - id: zeroes4
    contents: [0x00, 0x00, 0x00, 0x00]
  - size: 28
  - id: zeroes5
    contents: [0x00, 0x00, 0x00, 0x00]
  - size: 12
  - id: string1
    type: str
    size: 60
  - size: 24
  - id: zeroes6
    contents: [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]

instances:
  # file: 77G.MMW.automotive.radar-PCBF-V01-20180115-1520.brd
  # downloaded from https://github.com/OpenBoardView/OpenBoardView/issues/126
  
  # track_segment1: x=-18100 y=219000
  # pos: 0x25f284
  tracks_unknown:
    io: _root._io
    pos: 0x25f130  # hardcoded for now, only valid for this board
    type: tracks

  vias_unknown:
    io: _root._io
    pos: 0x2ea550  # hardcoded for now, only valid for this board
    type: vias

  # pad: 0x0032A990 - -233337 | 149000 | Pin2 | CAN_L

types:
  tracks:
    seq:
      - id: tracks
        type: track_seg
        repeat-expr: 20  # just show some vias to validate record
        repeat: expr

  vias:
    seq:
      - id: vias
        type: via_seg
        repeat-expr: 20  # just show some vias to validate record
        repeat: expr

  test:
    seq:
      - id: type_question_or_layer
        type: u4
      - id: data
        size: 32+4

  # TODO: offsets are wrong at some point
  track_seg:  # track_seg?
    seq:
      - id: type_question_or_layer  # no idea what this is, perhaps we can extract the record type -> size from it?
        type: u4
      - size: 4*4
      - id: width  # TODO: sometimes zero?
        type: s4
      - id: start
        type: point
      - id: end
        type: point


  # TODO: offsets are wrong at some point
  via_seg:
    seq:
      - id: position
        type: point
      - size: 4*5
      - id: rotation
        type: s4
      - size: 4*9

  point:
    seq:
      - id: x
        type: s4
      - id: y
        type: s4

• Figure out how to build the library and build an CLI application with main.cpp in one run.
• Figure out how to link the unit tests against the dynamic library

I am trying to follow the instructions in README.md. Under the Build header, it asks me to run:

cmake -B build -S . -DCMAKE_TOOLCHAIN_FILE=../vcpkg/scripts/buildsystems/vcpkg.cmake

but I don't see the file vcpkg.cmake in my repository. (And also the command seems to reference the parent folder above the repository.)

Tests that should be implemented into the CI.

Feel free to contribute some test files. A few points to note are listed in the following.

• If you vary a parameter e.g. an enum try to keep the rest of the parameters the same as for other variations of the same parameter. This simplifies finding the offset, when comparing two files byte-by-byte.

• Do not use 0.0 or other values that might occur elsewhere in the file for tests. Otherwise we might misinterpret some values and the test does not detect this.

• Units (enum)

• Decimal places (unsigned in range [0, 4])

• Start

  • Padstack usage (enum)

• Drill

  • Slot
    • Slot type (enum)
    • X size (unsigned)
    • Y size (unsigned)
      • X tolerance
        • +
        • -
      • Y tolerance
        • +
        • -
  • Drill hole
    • Hole type (enum)
    • Finished diameter (unsigned)
    • + Tolerance (unsigned)
    • - Tolerance (unsigned)
    • Drill tool size (string)
    • Non-standard drill (enum)
  • Hole plating
    • Hole/slot plating (enum)
  • Define the drill rows and columns
    • Number of drill rows (unsigned)
    • Number of drill columns (unsigned)
    • Clearance between columns (unsigned)
    • Clearance between rows (unsigned)
    • Drills are staggered (bool)

• Secondary Drill

  • Backdrill (bool)
    • Diameter (unsigned)
      • Backdrill drill symbol
        • Type of drill figure (enum)
        • Characters (string with <= 3 characters)
        • Drill figure width (unsigned)
        • Drill figure height (unsigned)
  • Counter bore/sink (bool)
    • Bore type (enum)
    • Diameter (unsigned)
    • + Tolerance (unsigned)
    • - Tolerance (unsigned)
    • Depth (unsigned)

• Drill Symbol

  • Define a drill symbol
    • Type of drill figure (enum)
    • Characters (string with <= 3 characters)
    • Drill figure width (unsigned)
    • Drill figure height (unsigned)

• Drill Offset

  • Offset from padstack origin to hole
    • Offset x (int)
    • Offset y (int)

• Design Layers

  • ...

• Mask Layers

  • ...

• Options

  • Suppress unconnected internal pads; legacy artwork (bool)
  • Lock layer span (bool)
  • Poly via (bool)