Embodiments relate generally to network hardware, network software and methods for network management and testing. The shape variation on interconnects is converted to variations in resistor-capacitor parasitics. In one embodiment, it is determined that the processor has flushed an internal cache of the processor to the system memory before placing the processor in the non-snoopable state. After the carriage has moved to a scan line, the reference point can be located according to the intersection points between the mark scanned and the scan line accompanied by the predefined function set of the mark.