Li Luo

Design and Verification of Multi-clock Domain Synchronizers

Clock domain crossing (CDC) is an important issue in integrated circuit (IC) design and verification. In this paper, We present the design of 5 types of CDC schemes in our developed SOC chip with multi working mode and ten clock domain, deeply describe an approach using assertion-based verification (ABV) to verify proper functionality for CDC signals. Taped sample chip tests show all CDC designs work right, and demonstrate that design and verification method are effective.

Hardware/Software partitioning for heterogeneous multicore SOC using particle swarm optimization and immune clone (PSO-IC ) algorithm

Hardware/Software partitioning is one of the critical steps in Hardware/Software Co-Design flow, and has very important influence on the system performance. Hardware/Software partitioning is also a NP-hard problem. In this paper, we present a new Hardware/Software partitioning algorithm called PSO-IC for heterogeneous multicore SOC, which combines particle swarm optimization (PSO) algorithm and immune clone (IC) algorithm. Comparing with GA and PSO algorithm, the experiment shows that our algorithm can acquire better trade-off between partitioning time and optimization quality. So our algorithm is an effective hardware/software partitioning algorithm.

Unified Protection Model of Application Files and User Files

Computer file is the main target of computer viruses. In order to protect the user files, Users intentions is introduced in this paper, its main idea is that whether meet the users intentions is the sole criterion to determine whether a program contains malicious. In addition, through make some access control rules for application files, the application files can be greatly protected. The paper integrates and expands these two ideas to construct a Unified Protection Model, and proves that the model has good safety properties, which can effectively protect the user files and application files.

A Protection Model of Application Files

Based on the research of technology that through which virus attacks the application, we find that an important reason of the application vulnerable to be attacked is the lack of effective access control to application files. In view of this problem, this paper build a protection model of Application files, combined with system snapshot technology. This model can give the application files real-time protection, effectively defend against virus attacks, and has good safety properties.

An Application Vulnerability Solution

With the development of computer and network technology, the security of application is becoming a key factor of system safety increasingly. So it is necessary to research the vulnerability problem of application. This paper firstly analyzes the vulnerability root of application, that is, operating system does not divide storage space strictly, and system does not implement strict access control to application files and system configuration files that the application relies on. Then, a solution for these problems is proposed, and finally implemented on Windows platform.

An Automatically Capture Method of User's Intention

Limiting the files set that the running program can access is an effective method of defense against file attack, but how to determine of the files set is a big problem. In this paper, we present the automatically capture method of User’s intention (UIAC). With the analysis of human-computer interaction, the system can dynamically and automatically determine the file-access permissions set. We introduce the main principle of UIAC, and give the overall architecture.

An Application Anti-Attack Model

With the development of computer technology and network application, the safety of application has become one of the most important research problems in the field of information security. Firstly, the paper analyzes malicious attack approaches for applications. Secondly, this article proposes an application anti-attack model (AAM), and further presents the formal description of the model. Finally, this paper represents its good security properties and proves them.

Anti-attack Model of Application in Storing State

The safety of application is one of the most important research problems in the field of information security. The paper firstly analyses the nature of application attack, and points out the vulnerabilities of application. Then the paper proposes an anti-attack model of application in storing state based on mandatory access control idea, and the model has good security properties that it can protect application from attacking in real-time. The paper presents a formal definition of the model and proves its security properties. Finally, an implementation solution of the model is given on Windows XP platform.

Design and Realization of an Optimized Memory Access Scheduler

Memory Wall is a bottleneck of enhancing the performance of computer system, and appearance of multiprocessors (CMPs) makes it more. How to reduce Memory Access Latency is a critical issue we have to deal with. Memory controller is difficult to optimize, the controller needs to obey all DRAM timing constraints to provide correct functionality. State-of –the-art DDR2 SDRAM chips often have a large number of timing constraints that must be obeyed when scheduling commands, for instance, over 50 timing constrains. We have made deep research on optimized memory access scheduling. In order to efficiently utilize the bandwidth and reduce the latency, Memory Access Scheduling optimization adapts the characters of DRAM to reschedule the memory access. By studying effective data bar which is generated by Genetic Algorithm, we mine four rules. So we just use these four rules to schedule in Memory Access Controller. The results of experiment show that compared with FR-FCFS (first-ready first-come first-serve) scheduling strategy, the rule based algorithm improves the performance of scheduling and the ideal speedup is near 1.5 times. The best speedup of the test of spec2000 is 1.467, and the worst speedup is 1.078.

A Novel Intelligent Object Storage Controller for High Performance Computing

The development of high performance computing has posed a tremendous demand on storage capacity and I/O performance, storage system has entered the Petabyte era. Application demands drive the change of storage architecture. Object-based storage is becoming the new direction of massive network storage systems. Object-based storage combines the advantages of SAN and NAS, adopts an object-based interface, and offloads some work of traditional file system to intelligent object-based storage devices, so greatly enhance the performance, reliability, and scalability of storage system. On the other hand, because the storage system scale of high performance computing is very large, the amount of storage nodes is very huge, so features such as power, size and weight have been the factors that cannot be neglected. This paper aims at the key component of object-based storage system - object storage controller, and proposes a novel design of object storage controller based on SOC. Measurement results show that the object storage controller designed by us not only optimize the performance of object-based storage system, but also has advantage in the respects of power, size and weight, so its very suit for building the object-based storage system for high performance computing.