Examples

Chapter 6. Examples

RS-FF Example

The example shows you how easy it is to create a simple flip flop.

The RS Flip Flop consists of two NAND gates. First we select a NAND gate for inserting to the Schematic View.

Click in the Component Supplier at the entry "Boolean" -> "Gates" -> "NAND".

The selected entry is highlighted.

Example RS FF (1)

Now we have to insert the NAND gate.

Move the mouse pointer to the Working View. In this area the mouse pointer converts into a cross cursor. This means KSimus is in "component insert mode". Move the mouse pointer to the position where you want to place the NAND gate. Click the left mouse button to place the new NAND gate.

Example RS FF (2)

KSimus stays in "component insert mode" until you click the right mouse button. Because of this, you are able to place immediately the second NAND gate below the first gate. After placing the second gate press the right mouse to leave the "component insert mode".

Now it is time to connect the components. First connect the output connector of the above NAND gate to one of the input gates of the below NAND gate.

Draw the mouse pointer to the output connector, press the left mouse button - hold it - move the mouse to the input gate and release the mouse button. There is no difference wether you connect the output to the input or reverse.

Example RS FF (3)

After releasing the left mouse button KSimus searches the best route for the wire.

Example RS FF (4)

Now we complete the circuit.

Place two buttons (entry "Boolean" -> "Input" -> "Button") and two LEDs (entry "Boolean" -> "Output" -> "LED"), and connect the components as shown below.

Tip

It is possible to connect to a wire as well as to a connector. It is also possible to connect two wires.

Example RS FF (5)

Now we have to negate the input connector of the NANDs which leads to the buttons.

Move the mouse pointer to the connector and press the right mouse button. Select from the popup menu the entry "Negate connector".

Example RS FF (6)

Do the same with the other NAND gate.

The current circuit has an unstable start condition. The circuit toggles until the user presses one button. This is preventable if we change the reset state of one of the NAND gates. Thereby the flip flop is forced into a stable start condition.

Move the mouse to the lower NAND, press the right mouse button and open the property dialog.

Example RS FF (7)

Set the "Reset State" to "True".

Example RS FF (9)

At least we want to change the title of the buttons.

Move the mouse to the button, press the right mouse button and open the property dialog.

Example RS FF (10)

Change the name to "Set" and press OK.

Example RS FF (11)

Rename the lower button to "Reset" and we are ready.

Now it is time to start the simulation. Press: Execute->start.

Load the example here.

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