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Traditional failure analysis (FA) process proceeds by investigating the tester results of several suspected silicon signals, and then applying CAD tools to navigate and compare pre-silicon design behaviors. However, existing CAD tools usually lack of design visibility due to the imperfect link between test and design environments. In this paper, we introduce a series of design visibility enhancement tools to augment FA process flow. These tools not only feature design comprehension and logic tracing capability, but also expand and correlate silicon data to design functionality. With the seamless visibility enhancement environment, we show the FA process can be performed more efficiently.

Embedded memory diagnostics is normally done by the built-in self-diagnosis (BISD) hardware, which collects and sends the diagnostic data to the external tester. The cost of the diagnosis process highly depends on the data volume sent between the chip under test and the tester, since the transmission time and the tester capture memory are major cost factors. We propose a memory BISD design using differential addressing, as well as a method for evaluating and choosing a proper differential address level. Based on our previous work on pattern identification BISD and syndrome compression design, the proposed differential address compression scheme further reduces the diagnostic data volume. Experimental results show that the BISD design is cost-effective.

With the advent of deep submicron technology and system-on-chip (SOC) design methodology, we are seeing on-chip memory cores to represent a growing percentage of the chip area. The yield of an SOC is usually dominated by the memory yield, so the improvement of memory yield is crucial in SOC development. In this work, we propose a built-in self-repair (BISR) scheme for memory yield improving. The novelty of our approach is that we can identify the fail patterns so that appropriate spare elements (e.g., spare rows, columns, words, or blocks) can be allocated to repair the defective memory. Some BISR methods are discussed and compared. We select the scheme that uses fewer spare elements than others given the same repair rate. The area overhead of the BISR scheme is only 2.2% for an 8K/spl times/64 memory.

We present a testable built-in self test(BIST) design for phase-lock loop(PLL). The design can measure the clock jitter for PLL with high precision and high accuracy due to better utilization of the test integration and test subtraction techniques. Although the BIST circuit is implemented by all digital standard cells to achieve better reliability, it can even be applied to measure the analog clock jitter. Besides, for some DfT (design for test) techniques inserted to make BIST itself testable, we discuss the trade-off among area, timing, number of test patterns and fault coverage in this paper.