A Hybrid Approach for Fast and Accurate Trace Signal Selection for Post-Silicon Debug

A major challenge in post-silicon debug is the lack of observability to the internal signals of a chip. Trace buffer technology provides one venue to address this challenge by online tracing of a few selected state elements. Due to the limited bandwidth of the trace buffer, only a few state elements can be selected for tracing. Recent research has focused on automated trace signal selection problem to maximize restoration of the untraced state elements using the few traced signals. Existing techniques can be categorized into high quality but slow simulation-based techniques and lower quality but much faster metric-based techniques. This paper presents a new trace signal selection technique which has comparable or better quality than simulation-based while it has a fast runtime, comparable to the metric-based techniques.