Symbol Library References dialog separates multi-unit symbols

[Evan Shultz]

See the screenshot in the second comment.

In the 7th row, Q2A and Q2B are shown as separate symbols. In fact, they are different units of a single part. I would think that one would always want all units in sync, and thus the entire symbol (not each unit) should be listed here (so just Q2). I don't see any facility to select individual units,so the entire symbol is updated at once, which just means showing each unit only lengthens the elements in the cell and adds visual clutter.

Naturally, I could be wrong. And it's a minor comment.

Note that this from the Raspberry Pi HAT template.

Application: kicad
Version: (5.1.2)-1, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.61.1 OpenSSL/1.1.1 (WinSSL) zlib/1.2.11 brotli/1.0.6 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.5) nghttp2/1.34.0
Platform: Windows 8 (build 9200), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8)
    Boost: 1.68.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.61.1
    Compiler: GCC 8.2.0 with C++ ABI 1013

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=OFF
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

[Wayne Stambaugh (stambaughw)]

We should drop the individual unit references and just add a single reference for the entire symbol.

[Ian McInerney (imcinerney)]

@Wayne, I don't think it is that simple. If the user just places the symbol from the library with the units and annotates, then what you suggest is fine. However, if the user were to then change one of the units to be from a different part and doesn't update the annotation, what you suggest would not work anymore.

For instance:
1) Open the pic_programmer example
2) Open "Edit symbol library links" and note that all of U2's parts are for 74LS125
3) Open the properties of U2B, and edit the library reference to be unit B of 74LVC125
4) Open the library links dialog again and see that now U2B is in a different row while U2A/C/D stayed in the same one

[Wayne Stambaugh (stambaughw)]

@Ian, you are correct. However, your example creates an ambiguous schematic. U2B cannot be a different part that U2A/C/D. I think the ERC will flag this. If not, it should. There is no way to know the user's intent in this case. Did they really want to use a different component or is this a new component and they forgot to update the reference? I don't want the schematic editor to make assumptions about the users design. It should only warn the user when something is amiss. I'm not sure we want to run an ERC to check for errors every time we launch the symbol table editor.

[KiCad Janitor (kicad-janitor)]

Fixed in revision 85eed87b2882ddfa9d27bf4a52e91d22be9f14f7
https://git.launchpad.net/kicad/patch/?id=85eed87b2882ddfa9d27bf4a52e91d22be9f14f7

[Evan Shultz (evan-shultz)]

Maybe I haven't thought though some caveat, but things look OK to me in a recent nightly. Screenshot for reference.

Application: Eeschema
Version: (5.1.0-1584-gc85d1fa00), release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.61.1 OpenSSL/1.1.1 (WinSSL) zlib/1.2.11 brotli/1.0.6 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.5) nghttp2/1.34.0
Platform: Windows 8 (build 9200), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8)
    Boost: 1.68.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.61.1
    Compiler: GCC 8.2.0 with C++ ABI 1013

Build settings:
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=OFF
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON