A flexible Boundary Scan test system is disclosed. The system includes an interpreter module operable to execute a program element selected from a plurality of program elements that include at least one instruction type having an interface to identify and execute selected functions wherein each of the selected functions has associated therewith at least one data information item. In one aspect of the invention, selected ones of the functions are composed of a plurality of functions. In another aspect of the invention, the instruction includes parameters and adornments for determining the selected function execution.