Before starting the schematic design let’s celebrate the fact that the most commonly used following shortcuts in our daily life are also valid for Electric VLSI.
Now we would build a resistive divider circuit.
Go to the schematic view of the Resistive_divider cell.
Select the N-Well resistor Node and then copy the same by pressing Ctrl+C.
Next click somewhere in the drawing area to deselect the Node. Press Ctrl+V and then left-click the mouse to paste the copied Node.
Next select the bottom resistor Node and use the menu item Edit –> Rotate –> 90 Degrees Counterclockwise (or just simply Ctrl+J) to get the following.
Move the newly created resistor apart from the earlier one so that the horizontal Node is above the vertical Node. Now you can connect both the resistors by using wire.
Wire Connection
Press Ctrl+G to highlight the grid on the screen if it is not already.
Next select the top Nodes right port, which makes this port active and thus ready of a wire connection.
Move the mouse cursor till above the vertical Node and RIGHT click the mouse to add and end the wire over there.
Next move the mouse cursor over the top port of the vertical resistor Node and RIGHT click the mouse button.
Part of Resistive_divider circuit showing the wire connection can be seen in the figure in right.
Press F5 to check the DRC error.
If you put your cursor over the corner in the wire, you will see a Pin. Sometime multiple Pins get introduced to wires unintentionally. A common error in a schematic is having unnecessary Pins.
Unnecessary Pins can be removed by going to the menu item Edit -> Cleanup Cell -> Cleanup Pins Everywhere.
Next add a couple more wires to complete the resistive divider circuit.
Remember to left click for selecting a port on a Node and right click to add the wire.
Label the Wires
We could add symbols for ground and a voltage source from the component menu but instead let’s simply label the wires in the schematic, which would be useful for SPICE simulation.
Select an Arc and press Ctrl+I to edit the properties of the Arc or simply just double-click on the Arc.
Label the Arcs as seen in the figure in right. Note that the bottom Arc is label gnd (a universal name for ground in SPICE; use lowercase).
You can move the level names up or down so that it will not be overlapped on the wire for a better aesthetic look.
Press F5 to check the DRC error.