Hi, I don’t really know how to use the type of hierarchical labels. Can someone explain to me in what situation I must use input, output , bidirectionnal, tri-state and passive label?
Thanks
I have never used hierarchical sheets. I have now tried (for first time) to place hierarchical label and see how it works.
The question is: Do ERC checks it. I don’t know and will not test it.
If yes then you must use right type of label to satisfy ERC. It should be easy to check which is good.
If no then you are not forced to use this or this type so you can use as looks better for you informing you for example what is signal direction here.
But, once more, it was first time I have seen them.
Oh okay. The thing is I think I understand input and output type of labels but I don’t understand bidirectionnal, passive and tri-state
Do you understand symbol pin types? There are even more types than here.
Pin types are only for ERC to check if there are no invalid connections done.
But with labels I don’t know if it is for ERC or only for what graphic you prefer.
The labels on the sheets mean the same as the labels on symbol pins. The only difference is the labels on the sheets are usually attached to wires leading off the sheet.
I still think they have no meaning for ERC, so it is the same but not exactly the same.
When you place label the radio buttons group used to select its type is named ‘Shape’ and not ‘Electrical type’.
If it should have the same meaning for ERC than the list should be longer (like power-input and so on).
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Not completely to be honest.
Hi @gnahore
This may help:
https://docs.kicad.org/7.0/en/eeschema/eeschema.html#symbols-and-symbol-libraries
Scroll down through this section to find the description and use for each pin “electrical” type.
There is also a section for Hierarchical Sheets Here: https://docs.kicad.org/7.0/en/eeschema/eeschema.html#hierarchical-schematics
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Piotr is right, the type of hierarchical labels is currently not checked in the ERC and therefore it’s only useful as graphical distinction between inputs/outputs.
So you could use any label shape you like, no functional difference.
I was writing about the meaning of the terms, I did not mention ERC. I don’t know if ERC is used with these labels.
EDIT: @mf_ibfeew has solved the ERC problem.
thank you, i think I understood a bit more. The outline shape of labels are purely visual.
About pin electrical type I would need some comfirmation please.
let’s use the symbol below as an example.
Intput type is use so that the stm32 will receives info only
Output type is use so that the stm32 will gives info only
Birectionnal type is use so that the stm32 will receives or gives info
Passive type is for conductors/ components that let the current through
Power input type is use so that the stm32 will be powered (3v3, 5V, GND).
Power ouput type would be use if the stm32 would powered another bloc-fonction.
Am I right?
For the most part yes.
Pin types input / output / bidirectional are more clear if you look at more traditional IC’s such as 74xx series TTL. Bidirectional and Tristate are there used for example for bus transceivers that can handle data in two directions (and can optionally be high impedant to free the bus).
Power Output are things that deliver power to your circuit, such as voltage regulators.
The “passive” pin type is a bit of a “there is no better way to name it”. For example pins of BJT’s and FET’s are also declared as passive.
But in the end, the pin types are only used for the ERC, and the input of ERC is Schematic Editor / File / Schematic Setup / Electrical Rules / Pin Conflicts Map (Shown below). That matrix defines which connections are allowed and which are flagged as warnings or errors by ERC.
Yes, but most important to understand is that all these stuff is only to satisfy ERC and you can run it or not.
The most often forum discussed problem related to pin types is: “ERC shouts at me that there is no power-output pin to supply power-input pins and what I should do about it?”
See:
Hi @gnahore ,
following on Piotr’s comment. Note the wording “on the same net” from the “Getting started” link.
If there is anything between the power flag and a power input pin the ERC will complain because the ERC is not smart.
The same goes for a signal out pin and a signal in pin. If there in a resistor in between, it is no longer one net, so the ERC will complain. This is why so many pins on ICs are labeled “passive”… the ERC doesn’t complain. 
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