What does the dashed line between diodes in a CMOS protection network mean?
The dashed line means that the diode is actually distributed across the resistor structure. The resistor is made using a doped region in the silicon, and there is an inherent PN junction between this doped region and the underlying silicon that contains it. So there is really just one diode, not two, but it is neither before nor after the resistor...it is part of the physical resistor structure itself.