Design methodology for small Real-Time capable embedded systems

Microprocessor-or microcontroller-based embedded systems scale from highend systems, based on 32-or 64-bit arehiteetures including a real-time operating system, down to the low-end using 8-or even 4-bit microcontroller. While the first class shows similar calculation capabilities like PCs or even workstations, the latter is found in approximately more than 90% of all applications. Though this number of low-end systems is substantially high, 'classical' computer science has always focused on the high-end side due to their intrinsic system aspect. In contrast this paper addresses the development of real-time capable low-cnd embedded systems introducing a design methodology. Application requirements are first classified, then implemented using different approaches and afterwards integrated. This methodology assures that, if worstcase execution times as the upper runtime limit fit for each specific part, the complete system will work in real-time.