Sharif Digital Repository

Energy consumption, area, reliability and predictability are the major concerns in embedded systems. Using scratchpad memories (SPMs) instead of cache memories has an increasing role to satisfy these limitations. SPM as an on-chip SRAM memory is highly vulnerable to soft errors and as it contains the most frequently used blocks of the program, errors in SPM can easily propagate in system leading to erroneous results. This thesis proposes two approaches to protect the SPM against soft errors. The first approach, MM-SPM, proposed to protect the instruction SPM and the second approach, CR-SPM, proposed to protect dynamically mapped data and instructions to the SPM. The main idea behind the... 

Ever increasing applications of embedded systems have motivated the designers to pay special attention to the design requirements of such systems. Among embedded applications, safety-critical systems have high reliability requirements as failures in such systems may endanger human life or result in catastrophic consequences. Embedded processors as the computation cores of embedded systems are very crucial from reliability point of view. This is because; a failure in the processor most probably leads to a system failure. One effective way to protect embedded processors against environmental faults is to use system level fault-tolerant techniques such as Master/Checker (M/C) or Triple Modular... 

In this thesis, we intend to propose low cost SED-tolerant techniques for different compo­ nents of embedded processors core including data path components such as register file and ALU as well as control path components such as control unit. Since the reliability es­ timation is the essential step in design of a fault-tolerant system, we propose fast and accu­ rate analytical soft error rate (SER) estimation techniques in Section 4. The proposed techniques have the ability to measure: 1) the SER of a design; 2) the SER of each indi­ vidual gate and FF, and 3) the SER of a specific path in the design. Using such infor­ mation, designers can selectively protect the vulnerable parts... 

Considering ever expanding applications of embedded systems in all aspects of human life, reliability and fault tolerance of these systems have become vital. To increase the reliability in a microprocessor as the most critical component of an embedded system, one may notice the essential role that is offered by its register bank. In fact the register bank is the most critical subcomponent of an embedded system, greatly affecting the reliability of the overall system. The operation of the embedded system is further critically affected through optimal and efficient usage of power as most systems relay on battery. In this project, to evaluate the availability of register banks various... 

In order to ensure the Immunity of integrated circuits against electromagnetic interference, integrated circuits should go under the sensitivity measurement test. This test consists of radiation or directly injecting electromagnetic interference. Injected disturbances are applied, either to the whole device or to one part of the device under test. Standard 62132 describes the specification of the methods for determining the sensitivity in frequencies between 150 kHz to 1 GHz. To provide a method which is capable of implementing and is controllable, it is necessary to study the standard models, and examine and discuss the strengths and weaknesses of each from the point of performance and... 

Memory organization plays an important role in embedded systems. Among the various component, memories as principle of consumption large amount of energy, are more important in power consumption, real time feature and fault tolerant of system.so that depend on system application, various configuration of memory organization are used…………. Memory organization issues include memory size, memory management methods, hardware management unit, cache, SPM and theirs subject and so on. This thesis discussed important topics related to energy consumption, real time and fault tolerant feature in memory organization and purposed a Configurable Description of Memory Organization for Low-Energy and... 

Ever increasing applications of embedded systems have motivated designers to pay special atten-tion to the design requirements of such systems. Among embedded applications, safety-critical sys-tems have high reliability requirements as failures in such systems may endanger human life or re-sult in catastrophic consequences. Embedded processors as the computation cores of embedded systems are very crucial from reliability point of view. Reducing feature size, power supply voltage and also increasing operating frequency have increased the occurance rate of transient faults in such processors. Built in Self-Test facilities available in many of embedded systems forms about 70% of total cost in... 

Dependability assessment is an important preliminary in the design of dependable systems. Simulation Based Fault Injection (SBFI) is a common way to evaluate system dependability. To achieve high accuracy in SBFI, a large amount number of fault injection is required, which is very time consuming. Many of ideas are implied to solve this disadvantage of SBFI. In this work, we propose a method that uses information of workload execution on the processor to reduce faults to be injected during the SBFI campaign. We concentrate on Single Event Upsets because of its majority and repeating interval. Our proposed method first gathers information about various regions of the processor by probing... 

The wide range of embedded processors and their reliance on nano-scale technologyhave brought them serious concerns on reliability, power consumption, timeliness and cost. Therefore, theseconcernsmust be addressed at the design process withemploying minimum facilities.This thesis proposes a low-cost concurrent error detection method based on control flow checking suitable for embedded processors. Most of the previous control flow checking methods either do not consider the embedded processors concerns, or they are not applicable to processors with on-chip cache memories.The key idea behind the proposed control flow checking method is to embed specific hardware components in the IP core of an... 

In recent years, the use of embedded processors has grown increasingly in wide range of computer systems; so that most of manufactured CPUs are used in emebedded systems many of which are safty-critical systems such as medical devices, aircraft flight control, space systems, nuclear systems, etc. The incidence of failure in these systems can cause irreversible damages on human life, financial or environmental matters. Silicon process technology trends, such as reducing the threshold voltage, increasing the frequency and decreasing the size of transistors, not only caused increase in single-bit fault rate but also caused occurance of multi-bit faults. Due to importance ofcorrect operation of... 

Nowadays, embedded processors are widely used in wide range of domains from low-power to safety-critical applications. By providing prominent features such as variant peripheral support and flexibility to partial or major design modifications, Field-Programmable Gate Arrays (FPGAs) are used in industry for implementing either an entire embedded system or a Hardware Description Language (HDL)-based processor, known as soft-core processor. FPGA-based designs, however, suffer from high power consumption, large die area, and low performance that hinders common use of soft-core processors. In this thesis, we present an efficient reconfigurable architecture to implement embedded processors in...