In this paper, we present a statistical power estimation method where estimation time and accuracy can be balanced by assigning smaller errors to the nodes with higher power dissipation and higher errors to the nodes with lower power dissipation. To calculate the error rates for individual nodes, a quadratic programming based problem will be formulated which incorporates the distribution data of all individual node switching activities. Also, an iterative statistical power estimation system will be presented. Finally, we will demonstrate experimental results which show drastic reduction in the number of simulation patterns compared to previous methods. 1.

This paper presents an algorithm which synthesises gate-level speed-independent control circuits directly from signal transition graphs (STGs) by analyzing the relations between the signal transitions in the STG. It uses an exhaustive approach to improve the performance of the synthesized circuit in terms of the circuit area and speed. The experimental results show that our algorithm yields more efficient circuits than the existing works in reasonable time.

This paper explores a test pattern generation problem for switch-level combinational circuits. In test generation for switch-level circuits, constraints on assignable logic values can be introduced due to the difference between the implicated logic values and the justifiable logic values of a logic element. Therefore, identifying unjustifiable logic values as early as possible would greatly accelerate the switch-level test generation. For this, a new logic value system called taboo logic value is proposed to represent the unjustifiable logic values of a node. Also, a new switch-level ATPG system is developed which employs a constraint-guided line justification method using taboo logic value. Finally, experimental results on various types of circuits demonstrate the efficiency of the proposed approach and the possibility of the practical application to large switch-level circuits.>

Delay testing at the operational system clock rate can detect system timing failures caused by delay faults. However, delay fault coverage in terms of the percentage of the number of tested faults may not be an effective measure of delay testing. A quantitative delay fault coverage model to provide a figure of merit for delay testing is presented. System sensitivity of a path to a delay fault along that path and the effectiveness of a delay test are described in terms of the propagation delay of the path under test and the delay defect size. A new statistical delay fault coverage model is established. A defect level model is also proposed as a function of the yield of a manufacturing process and the new statistical delay fault coverage. A new delay testing strategy driven by the defect level for delay faults is proposed.>

An efficient delay test generation (DTEST GEN) system for combinational logic circuits is presented. In the DTEST GEN system, delay testing problems are divided into gross delay faults and small delay faults separately so that the tradeoff between the levels of delay testing effort and the confidence levels of proper system operation can be explored. Complete automatic test pattern generation (ATPG) algorithms are proposed for both gross delay faults and small delay faults. A novel timing analysis method for delay test generation which uses a conventional depth-first search technique and a novel functionality analysis technique is introduced. The functionality analysis technique examines, necessary conditions for a given delay fault to be testable and estimates the upper bound of the good circuit propagation delay of the longest sensitizable path passing through the fault site. Several benchmark results are demonstrated for both gross delay fault testing and small delay fault testing.>

As electronic CAD synthesis tools become more powerful, they will increasingly refine delay measiirements and adjust path delays so as to increase the clock rate or to reduce the chip area. This paper discusses the implications of such events on testing for delay defects. We provide a timing optimization procedure and show that the resultant density function of path delays is a delta function. Finally, we discuss the impact of timing optimization on the yield of a manufacturing process and the defect level for delay faults.

This paper presents an efficient delay test generation system for combinational logic circuits. Delay testing problems are divided into gross delay fault testing and small delay fault testing in order to explore the trade-off between the levels of delay testing effort and the confidence levels of proper system operation. Complete automatic test pattern generation algorithms are proposed for both gross delay faults and small delay faults. Especially for the small delay fault test generation, new search space enumeration techniques are employed so as to bias the search space such that a delay test for relatively long paths can be found. Also a novel timing analysis method via functionality check is presented for delay test generation. Finally, complete test results are demonstrated for both gross delay faults and small delay faults on several benchmark circuits.

A quantitative delay fault coverage model is discussed to provide a figure of merit for delay testing. System sensitivity of a path to a delay fault along that path and the effectiveness of a delay test are described in terms of the propagation delay of the path under test and the delay defect size. A statistical delay fault coverage model is established. A defect-level model is also proposed as a function of the yield of a manufacturing process and the statistical delay fault coverage.>