Standardized Functional Verification- P7:Every manager who brings a design to tape-out or who purchases IP must eventually face these questions. The ability to answer these questions based on quantitative analysis is both vital and yet elusive. In spite of the enormous technical advances made in IC development and verification software, the answers to these questions are still based largely on guesswork and hand waving. | Counting Function Points 45 Variables of Condition Variables of condition are also time-variant but because they are by definition persistent it is useful to consider the valid tuples of values of condition to get a grasp on the multiplicity of function points corresponding to the many ways in which the system can be made to operate. Variables of condition are separated into two categories variables of internal condition and variables of external condition. Just as with variables of connectivity for a given tuple of values of internal condition there may be many valid tuples of external condition. Determining the number of combinations of persistent internal and external conditions can be accomplished algorithmically using nested for loops just as is done for determining the number of valid systems. A complete analysis of the conditional subspace includes not only direct conditions established during initialization but must also include indirect conditions that arise during the application of stimuli. Variables of Stimulus Continuing to variables of stimulus we recognize that they can also be separated into two categories variables of composition and variables of time. Values of these variables are quintessentially time-variant and counting the function points corresponding to variables of stimulus is extremely challenging but not impossible. This procedure will be highly dependent on the design being verified but is generally a two-dimensional problem along the axes of composition and time. Variables of Response The analysis of the size of the response subspace is identical to that for stimulus. Responses are values produced by the target and have values that vary in their composition as well as in their appearance in time particularly in concert with values of variables of stimulus. Arriving at an actual count of the function points in this subspace requires creation of value transition graphs just as for stimulus and other time-variant .
