Researches On Some Key Techniques Of Hardware/Software Co-Design

Hardware/software co-design is a fruitful approach that combines the hardware and software perspectives from the earliest stages of the design process and exploits the synergism of hardware and software through their concurrent design to meet system-level objectives [DM91][GDM97]. With the information technology developing rapidly, the research of hardware/software co-design techniques has become a hot spot of the academe and industry.The faculties at VLSI&System lab (ICS lab) of the Darmstadt Technical University have been researching on the co-design techniques for a decade and have made excellent achievements in the spectrum of modeling, design and validating [DAR00]. Recently they put forward a system-modeling tool CDM and applied it in the design of MP3 player and robot. This paper is based on the cooperative research of some hardware/software co-design techniques with the Darmstadt Technical University, which is supported by the Research & Development Foundation of Shanghai Science and Technology.Hardware/software co-synthesis technique is a key technique in the co-design area. A hardware/software co-synthesis algorithm COSMT is proposed in this paper. Compared with the traditional co-synthesis techniques [BGN97][BN98][RN98₂], this one has following features: 1) COSMT targets at the co-synthesis of the embedded systems which are characteristic with the mixture of hard real-time and soft real-time constraints.2) a slack steal schedule policy [RKA93] based on RMA [CJ73] is adopted to meet the hard and softreal time constraints.3) a hardware connective structure formulation sub-algorithm is proposed. This sub-algorithm can generate hardware topology structure, which meets the real-time constraints, and enhances the system reliability by decreasing the contention of communication events with hard real-time constraints, and reducing the routing complexity of communication events with soft real-time constraints. 4) An approximate Pareto-ranking [BGN97] method is proposed to meet multi objects with different weights in the evolvement sub-algorithm.In the field of hardware/software co-design, it is a difficult problem to transform the design from the abstract description on high level to an implementation on lower level. In this paper, an auto-generating algorithm is developed to convert the design from its abstract high-level model (CDM model) into the framework of the behavior-level SystemC code of components. An experiment indicates that the generated SystemC code can meet the functional requirements, hard real-time constraints and soft real-time constraints.Internal design representation technique is also an important technique of co-design that can support designers to establish the representation model of the internal design and explicitly describe the control flow, data flow and time feature of the design in order to analyze and explore the internal design carefully. In this paper, the author proposes a double transition timed Petri net (DTTPN) and hierarchical DTTPN (HDTTPN), which can not only represent the data flow and control flow separately, but also represent the time features in the same model. With the support of the DTTPN, designers can explore the design in the control and data field simultaneously, and investigate the timing property as well.As the above researches show, the author has studied the key techniques systematically in the design phases including system architecture design, and component design and implementation. And a series of co-design tools and algorithms are proposed on the basis ofCDM.The hardware/software co-design platform ROCS is an experimental system with the foregoing techniques. With the support of ROCS, designers can specify system with CDM in textual or graphical style, co-synthesis the CDM model into system architecture description, and automatically generate the framework of behavior-level code in SystemC. In this thesis, the system design of ROCS is introduced and the details about the application of the above techniques are presented. Then, an experiment of PDA design...