Hierarchical sheets in KiCAD

When working with larger design, it is convenient to spread the design across multiple schematic sheet with each schematic sheet containing one major section of design. Also these multiple sheets has to be connected between then. This can be done in multiple way. Here is the summary of it.

Hierarchical Navigation Buttons

Hierarchical Navigation Buttons

Button “4. Hierarchical sheet” is used for creating multiple sheets. From the main sheet press “4. Hierarchical sheet”, enter sheet name and schematic file name to create new Hierarchical sheet.

hierarchical sheet placement

hierarchical sheet placement

Button “7. Navigate between sheet” can be used to navigate between root sheet and sub-sheet.

To connect items within a sheet either wire or bus or “1. Net label (local)” can be used. But not of these can be used for connecting wires between multiple hierarchical sheets.

There are two methods for connecting wires between multiple sheet.

One method is by using “2. Net Label (global)”. Any two pins connected with this thorough the schematic hierarchy are connected. These labels can be two or more of the same net. Disadvantage with this is that, this is not neat way of connecting pins between hierarchy sheets. It is almost like using global variables in an C project. It is quick and fast but as design it is hard to keep track of nets and it is not neat.

Second methods is by using Hierarchical label and Hierarchical pin pair between sheets.

First place the hierarchical label on the sub sheet using “3. Hierarchical Label”, as shown on figure below.

hierarchical label placement

hierarchical label placement

Now go to the root/main sheet and import all the hierarchical label. This can be done by importing Hierarchical label Press Button 5, “5. Import Hierarchical label” and click on the sheet label of sub sheet. This will automatically import all the Hierarchical Labels of the sub sheet as Hierarchical pin, one click at a time. POT_U_D, _POT1_CS and _POT2_CS in above case. This Hierarchical pin can be be configured as input, output, passive etc.

hierarchical pin on main sheet

hierarchical pin on main sheet

Hierarchical pin can be placed manually by using “6. Hierarchical Pin” but this is not convenient compared to method above.

Finally Wire or Local Net Label on main sheet can be used to connect to Hierarchical Pin within main sheet.