This paper analyzes the potential performance of a high-level language (HLL) microprocessor architecture for special- purpose real-time applications. Our approach is based on mapping of HLL constructs into microcode, a concept called vertical migration. An analytical execution-time model of the reduced vertical-migration architecture is developed. It is applied to two different workload models: one corresponding to statement mixes, and the other showing some HLL kernel routines. Performance evaluation results are compared to different forms of the reduced vertical-migration architecture, and in various application domains. We underline in this paper the, basic relationships among microprocessor architecture, GaAs technology, and real-time applications.