Suppose you are in the process of creating a PCB using ARES. While routing Tracks, You often come across situations where you have to modify the circuit connections to Add/Remove some components or modify existing connections.
This can be done in two ways
1. Netlist Clearing method
Here you have to draw new connections without any reference circuit Netlist .
Step 1: Clear the Current Netlist
Go to File>>Clear Netlist
Step 2: Manually edit the connections.
Note: By doing so ARES will not have any idea about the connections so will be unable to warn you about incorrect connections. So this method is not recommended.
2. Import Modified Netlist Method
I am explaining this method using an example circuit which i used to demonstrate the Arduino shield tutorial.
Suppose you have created a layout "Example.LYT" using the circuit connections defined by the ISIS file "Example.DSN".
Download Example.LYT
Download Example.DSN
Here is a screen shot of current layout
Now we are supposed to make the following corrections to this circuit.
1. Add a capacitor between VCC & GND.
2. Connect PIN 2 of Demo Chip to PIN 8 of Digital I/O port 1 instead of PIN 6
Instead of starting from scratch you can use the following method to modify the existing layout.
Step 1: Open ISIS & Modify the circuit.
>>Open .DSN file of the circuit to be modified in ISIS.
>>Make the necessary changes in circuit.
>>Save the changes
Here is the screen shots before and after modifications
| Before |
| After |
| Netlist compiler options |
Output option must be files(s) & Format should be SDF. Leave other settings to default. Hit OK to bring up the Compile Netlist window.
Note: Save Netlist with a new File name.
Step 2:Open ARES & Load the modified Netlist
>>Open Example.LYT
>>From Menu Open File->Load Netlist
>>Open the .SDF file you saved in last Step
New Netlist is loaded and can see the changes made by the new Netlist in this screenshot .
>>Delete invalid connections shown as an yellow line, place new components and draw the modified tracks.
Final circuit will look like this.
Wooho its Done!!!!!
