Through addressing circuitry, a sampling circuit can choose a unique
internal node/signal on an encapsulated/packaged chip to be output to one
or more drivers. The chosen signals available at the target node are
directed either through a select circuit to an output pin, or directly to
an output pin. In a preferred mode, decode circuits used to select a
unique node are serially connected, allowing for a large number of
signals to be made available for analyzing without a large impact on
circuit layout.