Digital storage element with dual behavior

摘要

A digital storage element comprises a master transparent latch that receives functional data from a data input port and scan data from a scan input port and a slave transparent latch coupled to the master transparent latch. The slave transparent latch comprises dedicated functional data and scan data output ports. The master and slave transparent latches have opposite transparent polarities when in a functional mode and have the same polarities (e.g., positive level sense) when in a scan mode. The transparent polarity of a transparent latch defines the state of a clock to that latch for which the transparent latch is transparent.