Games / Command flash cards / OpenROAD flow commands / 3D packaging (3DBlox)

3D packaging (3DBlox)

Each card shows a command to explain. A missed card returns later in the round and starts the schedule over. A card answered correctly moves up the schedule and next appears after 1, 3, 7, then 21 days. Keys 1 to 4 choose an option, h shows a hint, and Enter moves on. A hint keeps the card where it is on the schedule. An ordering card is answered by clicking its items in order, and one wrong click ends it. Time values are in nanoseconds. Progress is stored in this browser.

SourceThese cards follow OpenROAD's own commands, checked against the signatures printed by the tool (OpenROAD 26Q3) and the documentation of the module that implements each one. Each answer links to that module's documentation. Commands differ between versions, and commercial tools use different names entirely. Reference: OpenROAD module documentation (OpenROAD on GitHub).
All 4 cards in this section, with answers
  • read_3dbx stack.3dbx
    Reads a description of a die stack and its chiplets.

    Hint: One file describes several dies and how they sit together.

    The file names the chiplets, their instances, and how they bond. 3Dblox, standardized as IEEE 3537, is a language for describing chiplets and their interconnection in 2.5D and 3D packaging: size, orientation, interfaces, thickness, and interconnect regions. Reading one gives OpenROAD the stack to work on. OpenROAD reference

  • report_3dic_summary
    Prints the stack's structure, counted piece by piece.

    Hint: A structural summary: counts and names, not measurements.

    The counts are of chiplets, top-level chip nets, bond regions, and bump pads, and each chip instance is listed with the chiplet it refers to. It is the sanity check after reading a stack, before anything that depends on it, such as timing across chiplets. OpenROAD reference

  • add_3dblox_alignment_marker_rule -master_a MARK_A -master_b MARK_B -tolerance 0.5
    Requires the paired markers on bonded chiplets to sit within 0.5 microns.

    Hint: Two dies are bonded face to face; something has to line up.

    Bonded dies carry marker cells that must land on top of each other. The rule pairs the two masters and sets the largest centre-to-centre misalignment allowed; -relative_orientations also constrains how one may be turned relative to the other. The checker enforces it. OpenROAD reference

  • check_3dblox
    Checks the stack description that has been read for problems.

    Hint: It takes no arguments, so ask what it must already have to work on.

    The checks cover the loaded description, including the alignment marker rules registered for bonded chiplets. This part of OpenROAD is new and its documentation is thin, so the tool's own messages are the best guide. OpenROAD reference