connect(layer1, layer2, actionlayer). . . which tells LEdit to connect layer1 to layer2 in the netlist if they overlap each other and both overlap the actionlayer. Note that layer1 or layer2 can be identical to the actionlayer, in which case everytime layer1 and layer2 overlapped, they would be connected.
The second part covers how elements are recognized and extracted. The syntax is as follows:
# The BogusMOS structure device = SUBCKT( RLAYER = BogusMOSgate; Drain = native diffusion, WIDTH; Sink = poly not resistor; Stopper = native diffusion, WIDTH; Bulk = all bulks; MODEL = bogusmos; )In our 'BogusMOS' example, the first thing we notice is the comment with a pound sign at the start helping anyone reading this .ext file.
Next, is the 'device' directive. We define this device as a 'SUBCKT' or sub-circuit, a very general way to describe a circuit element in in spice terminology. A SUBCKT in a spice file can be composed of other spice elements, or be an element itself with no more primitive contents.