To achieve this, the pattern cycle is divided into 100 time segments by default. Each segment is initialized to be stable, denoted by '-'. Every time a signal change occurs, it's corresponding time segment is set to be instable, denoted by 'X'. As a result, you will get a graph and a list displaying stable and instable regions for each signal.
Stable regions calculated here heavily depend on the pattern data.
There are two ways to get meaningful results. Second, and this is the recommended way, carefully survey your pattern data for a representative profile.