This article describes how future Single-Chip ECU's can be debugged and calibrated using the new emerging debug standard known as GEPDIS informally named NEXUS.The paper explains why conventional debug and calibration methods no longer work with future ECU architectures. Infineon Technologies and some other leading semiconductor vendors and tool companies have worked on the development of a ‘global embedded processor debug interface standard’ called GEPDIS (1). Throughout this paper will use the GEPDIS short cut. The GEPDIS standard defines and implements a global, open, micro-controller development interface standard for embedded controller applications. The GEPDIS interface can be used for run-time Control, Code Execution and Data Trace, Calibration and Co-processor communication (for use in Rapid Prototyping).