Multifunctional components are components that contain multiple different function blocks. For example, component 74HC7075 contains two inverters, two NAND gates with two inputs and two D-type flip-flops. It is possible to represent this component with a single symbol representing the entire component but, in many cases, it is more convenient to be able to draw individual gates separately so that each gate can be positioned independently of the others at any point in the schematic.
To define multifunctional components
An entire page must be dedicated to a single multifunctional component, bringing together all the symbols that represent it. Perform the following operations:
In the Page properties dialog you have to activate the Symbols » The page describes a single component option.
You have to define many different symbols (and therefore with a different part number) for each function block in the component. Where possible, other alternative symbols such as IEEE symbols can be defined. All alternative symbols must have the same part number. All symbols must be defined on the same page. For example, for component 74HC7075:
-
Inverter symbol plus alternative IEEE symbol. Symbols
e 
. Part number #1.
This symbol is multi-part and defines sections 1 and 2 of the component. -
Two input NAND port symbol plus the alternative IEEE symbol. Symbols
e 
. Part number #2.
This symbol defines section 3 of the component. -
Flip-Flop symbol plus the alternative IEEE symbol. Symbols
e 
. Part number #3.
This symbol is multi-part and defines sections 4 and 5 of the component. -
Two input NAND port symbol plus the alternative IEEE symbol. Symbols
e 
. Part number #4.
This symbol defines section 6 of the component.
-
Set the page name to match the symbol name. The name of the symbol to be specified in the library component card corresponds to the page name.
 Note: |
|---|
The order of the function blocks is determined by the part number assigned to the frame enclosing the symbol. |
The Pins of a Multi-Part Symbol
If a symbol is used to represent several parts of the same functional block then for each pin, present in the symbol, you must specify, separating them with commas, the numbers and the names that the pin assumes relative to each part.
For example, the following values must be specified for the INVERTER section of the 74HC75 component:
| Pin | Number | Name |
|---|---|---|
Input A INV |
1,22 |
1A,2A |
Output Y INV |
23,2 |
1Y,2Y |
To highlight the part number
In order to graphically differentiate the different parts of a multifunctional component, you can add a text object in the graphic symbol that includes the field code "Part Reference" or "Part Index". When the symbol is placed in the schematic, the field code is replaced by the section index.
Also define the symbol of the entire component
In addition to symbols representing only a single function block of the component,
you can also define a symbol (
and 
) to represent the entire component.
For this symbol, the option Full symbol must be enabled in the properties dialog of the frame object.
The part number #1 can be used for the whole component symbol.
Hide power pins
If you want to hide the power pins of a component, enable the Hidden pin option in the Pin object properties dialog box. When the netlist is created, all hidden pins are automatically connected to other hidden pins with the same name and to connections with the same name. The Hidden pin option only takes effect if the pin is included in a symbol. The free pins on a symbol definition page are always visible even if the option is active.
Also define the power pin symbol
If the component has power pins, you can define a symbol 
containing only power pins.
The symbol for the power supply pins only, can be useful in the schematic drawing to position the power supply pins of the integrated circuits separately from the individual gates.
The symbol for power supply pins only must have the part number equal to zero and the Power category.
Example of a page for defining the symbol for component 74HC75
