Abstract: Based on hardware/software codesign, a new kind of system level simulation, emulation and debugging method（called SSED） is proposed, which can be conveniently used in processor design. This method can be described as follows: set up execution environment according to real world applications;translate C program into assembly program, execution code and input vector which is used in simulation and emulation; debug VHDL program with assembler program under a kind of time model; analyze the execution results. The design and implementation of Jbcore16 processor indicates that SSED can increase verification efficience and accelerate processor design and implementation speed.