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Hitchhiker's Guide to Making a PCB (view source)
Revision as of 08:04, 21 November 2018
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* All sheets have a position in the ''hierarchy'', with one sheet at the top (hence "TopSheet.SchLib") and all other sheets one or more levels below.
* All sheets have a position in the ''hierarchy'', with one sheet at the top (hence "TopSheet.SchLib") and all other sheets one or more levels below.
* Sheets get a place in the hierarchy by being referenced with "sheet symbols" (see [[#Adding Sheets]] below). Any sheet that has a sheet symbol for another sheet gets a copy hierarchically beneath it. This means that your top sheet will have a sheet symbol for each second level sheet, which may each in turn have one or more lower level sheets (though this is uncommon).
* Sheets get a place in the hierarchy by being referenced with ''sheet symbols'' (see [[#Connecting Sheets|Connecting Sheets]] below). Any sheet that has a sheet symbol for another sheet gets a copy hierarchically beneath it. This means that your top sheet will have a sheet symbol for each second level sheet, which may each in turn have one or more lower level sheets (though this is uncommon).
* There is one unique, editable sheet file for each unique sheet in your design, but by duplicating its sheet symbol you can produce a duplicate copy of the circuit it contains in your design. This is useful for PCBs with repeated circuits - for example, ValBal avionics have two identical copies of the same motor driver circuit, one for each of the two motors in the system.
* There is one unique, editable sheet file for each unique sheet in your design, but by duplicating its sheet symbol you can produce a duplicate copy of the circuit it contains in your design. This is useful for PCBs with repeated circuits - for example, ValBal avionics have two identical copies of the same motor driver circuit, one for each of the two motors in the system.
* Unless explicitly connected (see [[#Connecting Sheets]] for how), wires on different sheets are not connected to each other by shared names. This means two wires labeled "SIGNAL1" on two separate sheets - even two copies of the same sheet - are not automatically connected. Importantly, this means that you need to add explicit connections for power and ground between sheets to make sure all sheets are powered.
* Unless explicitly connected (see [[#Connecting Sheets|Connecting Sheets]] for how), wires on different sheets are not connected to each other by shared names. This means two wires labeled "SIGNAL1" on two separate sheets - even two copies of the same sheet - are not automatically connected. '''Importantly, this means that you need to add explicit connections for power and ground between sheets to make sure all sheets are powered.'''
===Adding Sheets===
===Adding Sheets===
===Connecting Sheets===
===Connecting Sheets===
[[File:Ports.png|thumb|200px|right|The four flavors of port. The use of unspecified ports is discouraged]]
After adding a sheet (whether new or reused), you will need to connect it into your design (see [[#Using Multiple Sheets| above]]). To pass wires (i.e. power, ground, and signals of interest) between your sheet and another, your new sheet will need to have ''ports''. Ports are placed using Place → Port. (shortcut {{altium-shortcut| p → r}}). A reused sheet will likely already have ports on it, but make sure they're the ports you want and change them as needed.
===Applying the SSI Schematic Template===
===Applying the SSI Schematic Template===