Timing:

# Switching activity of the digital circuit:

We deal with metal layers and accordingly we calculate the timing. Before going into it lets see how the waveform changes wrt the circuit.

Resistance of any metal piece depends on the resistivity of the metal layer, length of the metal layers and the area of the metal layer.

Resistance = Resistivity of the metal layer * (length of metal piece /Area of the metal piece)

Capacitance is always defined in between the metal layers, and depends on the permittivity between the metal layers, area of the metal layer which is in parallel and distance between the metal layers.

Capacitance = Permittivity * (Area of the parallel plate/Distance between the metal layers)

Let’s look into the metal routing and how extraction results into. The below picture says how the extraction tool looks when it sees metal layers.

Let’s take one example on how the circuit results into practically. The input of this circuit is Vin and output is Vout. The relation between input and output is depends upon the R and C present in the path.