Abstract: The design of a 32-bit embedded RISC microprocessor NRS4000 is described, which is compatible with Intel 80960KA at instruction set level. The microprocessor with a 512K-byte instruction cache, a 5-stage pipeline, and a large register file, is implemented in the scale of 300K equivalent gates. In section l, the overview of NRS4oOO is given.In section 2, the data path of NRS4000 is proposed and the design method of control path is confirmed. In section 3, a control path design scheme on the core RISC micro-operations is presented, which simplifies the control path design of NRS4000, supplies the flexibility and extendibility in its control path design, and also makes it possible to develop the more fine parallelism further. In section 4, a high performance 5-stage pipeline is designed. To coordinate the dependencies between instructions executed in 5-stage pipeline, an effective resolution using hardware and software techniques is shown. In section 5, the logical design of NRS4000 is given. ln section 6, the VHDL description and simulation are introduced. In section 7, some conclusions are given. The top-down design of a self-made patent microprocessor using the high-level synthesis is an effective way under present clrcumstances.