To guarantee that an application-specific integrated circuit (ASIC) meets its timing requirement, at-speed scan testing becomes an indispensable procedure for verifying the performance of ASIC. However, at-speed scan test suffers the test-induced yield loss. Because the switching-activity in test mode is much higher than that in normal mode, the switching-induced large current drawn causes severe IR drop and increases gate delay. X-filling is the most commonly used technique to reduce IR-drop effect during at-speed test. However, the effectiveness of X-filling depends on the number and the characteristic of X-bit distribution. In this paper, we propose a physical-location-aware X-identification which redistributes X-bits so that the maximum switching-activity is guaranteed to be reduced after X-filling. We estimate IR-drop using RedHawk tool and the experimental results on ITC'99 show that our method has an average of 9.42% more reduction of maximum IR-drop as compared to a previous work which redistributes X-bits evenly in all test vectors.

To guarantee that an application specific integrated circuits (ASIC) meets its timing requirement, at-speed scan testing becomes an indispensable procedure for verifying the performance of ASIC. However, at-speed scan test suffers the test-induced yield loss. Because the switching activity in test mode is much higher than that in normal mode, the switching-induced large current drawn causes severe IR drop and increases gate delay. X-filling is the most commonly used technique to reduce IR-drop effect during at-speed test. However, the effectiveness of X-filling depends on the number and the characteristic of X-bit distribution. In this paper, we propose a physical-location-aware X-identification which redistributes faults so that the maximum switching activity is guaranteed to be reduced after X-filling. The experimental results on ITC'99 show that our method has an average of 8.54% more reduction of maximum IR-drop as compared to a previous work which re-distributes X-bits evenly in all test vectors.

This paper presents the systematic methodology of error correction scheme using low-density parity check (LDPC) codes to improve the reliability and endurance of multi-level cell (MLC) non-volatile memories. Using our realistic error model, the LDPC architecture with the scheme of non-uniform reference voltages (NURV) is proposed to trade off among error correction capability, area, and throughput, which can improve the bit-error-rate significantly.

The IR-drop problem during test mode exacerbates delay defects and results in false failures. In this paper, we take theX-fillingapproach to reduce the IR-drop effect during an at-speed test. The main difference between our approach and the previous X-filling approaches lies in two aspects. The first one is that we take the spatial information into consideration in our approach. The second one is how X-filling is performed. We propose a backward-propagation technique instead of a forward-propagation approach taken in previous work. The experimental results show that our approach can reduce 21.1% of the maximum IR-drop in the best case and 9.1% on the average as compared to previous work.

In this paper, we propose a technology mapping algorithm for CPLD architectures. Our algorithm proceeds in two phases: mapping for single-output PLAs and packing for multiple-output PLAs. In the mapping phase we propose a look-up-table (LUT) based mapping algorithm. We will take advantage of existing LUT mapping algorithms for area and depth minimization. Benchmark results show that our algorithm produce better results in terms of area and depth as compared to TEMPLA.