Sharif Digital Repository

In this work we propose using heterogeneous interconnects in power-aware chip multiprocessors (also referred to as Helia). Helia improves energy efficiency in snoop-based chip multiprocessors as it eliminates unnecessary activities in both interconnect and cache. This is achieved by using innovative snoop filtering mechanisms coupled with wire management techniques. Our optimizations rely on the observation that a high percentage of cache mismatches could be detected by utilizing a small subset but highly informative portion of the tag bits. Helia comes in two variations: source-based (S-Helia) and destination-based (D-Helia). S-Helia relies on a global snapshot of remote caches collected in... 

In this work we introduce power optimizations relying on partial tag comparison (PTC) in snoop-based chip multiprocessors. Our optimizations rely on the observation that detecting tag mismatches in a snoop-based chip multiprocessor does not require aggressively processing the entire tag. In fact, a high percentage of cache mismatches could be detected by utilizing a small subset but highly informative portion of the tag bits. Based on this, we introduce a source-based snoop filtering mechanism referred to as S-PTC. In S-PTC possible remote tag mismatches are detected prior to sending the request. We reduce power as S-PTC prevents sending unnecessary snoops and avoids unessential tag lookups... 

In this paper, we enhance previously suggested vulnerability estimation techniques by presenting a detailed modeling technique based on Input-to-Output Masking (IOM). Moreover we use our model to compute the System-level Vulnerability Factor (SVF) for data-path components in a highperformance processor. As we show, recent suggested estimation techniques overlook the issue of error masking, mainly focusing on time periods in which an error could potentially propagate in the system. In this work we show that this is incomplete as it ignores the masking impact. Our results show that including the IOM factor can significantly affect the system-level vulnerability for data-path components. As a... 

Over the past few years, radiation-induced transient errors, also referred to as soft errors, have been a severe threat to the data integrity of high-end and mainstream processors. Recent studies show that cache memories are among the most vulnerable components to soft errors within high-performance processors. Accurate modeling of the Vulnerability Factor (VF) is an essential step towards developing cost-effective protection techniques for cache memory. Although Fault Injection (FI) techniques can provide relatively accurate VF estimations they are often very time consuming. To overcome the limitation, recent analytical models were proposed to compute the cache VF in a timely fashion. In... 

This book present the lecture notes used in two courses that the late Professor Kasra Barkeshli had offered at Sharif University of Technology, namely, . The prerequisite for the sequence is vector calculus and electromagnetic fields and waves. Some familiarity with Green's functions and integral equations is desirable but not necessary.
The book provides a brief but concise introduction to classical topics in the field. It is divided into three parts including annexes. Part I covers principle of electromagnetic theory. The discussion starts with a review of the Maxwell's equations in differential and integral forms and basic boundary conditions. The solution of inhomogeneous wave...