A first scan data is received at a first scan chain and a representation of the first scan data is subsequently provided from the first scan chain to a second scan chain to test the second scan chain in response to a first value at a first bond pad. In one embodiment, the die package comprises a redistribution layer interconnecting two or more dies disposed on a substrate, typically a semiconductor wafer, the redistribution layer including a first trace connecting a bond pad of each of two dies, and a second trace connecting one of the bond pads of the two dies to a ball pad. Thereby, an internal moment of a shadow mask structure can be decreased, and thus, displacement of the shadow mask in the axial direction is suppressed even when the shadow mask is expanded by heat generated by impact of electron beams, and q-value deviation is suppressed as well. At least one marker is positioned proximate to the intended path, for transmitting a rotating dipole field to expose a portion of the intended path to the field for reception by the receiver. A second filter responsive to an output of the first filter, the second filter including M tap weight coefficients, wherein N is greater than M.