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[WARNING]: All internal macros will not be connected to power.

Open mithro opened this issue 3 years ago • 5 comments

In the MPW-6 walkthrough at 23:24 a bunch of warnings are shown in the output which say;

[WARNING]: Skipping Tap/Decap Insertion.
[WARNING]: All internal macros will not be connected to power.
[WARNING]: All internal macros will not be connected to power.
[WARNING]: All internal macros will not be connected to power.

See also image below; image

@mattvenn then says "I don't know really what those messages mean but it's not true at least in most cases I've seen".

This is bad -- one of the following things is happening;

  • The warning is being incorrectly reported when it shouldn't be.
  • The warning actually means something and is important.

The fact the warning is reported 3 times is also very suspect.

mithro avatar Jun 02 '22 00:06 mithro

https://skywater-pdk.slack.com/archives/C017HPHCMEY/p1653806889160399

mattvenn avatar Jun 02 '22 15:06 mattvenn

https://skywater-pdk.slack.com/archives/C016G7Z8GDR/p1640693345183700

mattvenn avatar Jun 02 '22 15:06 mattvenn

In the MPW-6 walkthrough at 23:24 a bunch of warnings are shown in the output which say;

[WARNING]: Skipping Tap/Decap Insertion.
[WARNING]: All internal macros will not be connected to power.
[WARNING]: All internal macros will not be connected to power.
[WARNING]: All internal macros will not be connected to power.

See also image below; image

@mattvenn then says "I don't know really what those messages mean but it's not true at least in most cases I've seen".

This is bad -- one of the following things is happening;

  • The warning is being incorrectly reported when it shouldn't be.
  • The warning actually means something and is important.

The fact the warning is reported 3 times is also very suspect.

Caravel user area PDN has two Digital and two analog voltage networks, each fed from either left or right side of Caravel harness. Most of design macros are connected with only one network, a choice made by using VDD_NETS and GND_NETS in macro-related config.tcl. Obviously, macros are not connected with rest of power networks, thus have exactly three sets of warnings.

tamood avatar Jun 03 '22 15:06 tamood

So, either; (a) the macros shouldn't be connected to the extra power rails and thus everything is fine (b) the macros should be connected to these extra power rails and thus should be an error

mithro avatar Jun 03 '22 16:06 mithro

So, either; (a) the macros shouldn't be connected to the extra power rails and thus everything is fine (b) the macros should be connected to these extra power rails and thus should be an error

The answer is (a). Moreover it looks like that this ambiguity has been taken care of in https://github.com/The-OpenROAD-Project/OpenLane/pull/1059.

tamood avatar Jun 06 '22 06:06 tamood