1. A data processing device comprising: a semiconductor chip; an electronic processor on-chip; an on-chip condition sensor connected to said electronic processor for analysis of the operations thereof, including means for recognizing the occurrence of a predetermined condition during real time operation of said electronic processor and means responsive to the recognition of said predetermined condition for applying a control input to said electronic processor during said real time operation thereof; and a serial scan circuit connected to said on-chip condition sensor for inputting to said on-chip condition sensor control information which causes said on-chip sensor to assume a selected one of a plurality of sensing configurations; wherein said on-chip sensor includes a plurality of sensor circuits responsive to particular internal conditions of said electronic processor and sensor circuit selection circuitry.