A new class of test instrument: the FPGA based module

Over the years of developing digital tests, I have struggled with a primary test philosophy: test the circuit as it is used in the system. This has been a struggle because traditional digital test instrumentation does not allow increasingly complex digital circuitry to be tested as it is used by the host system. True as used testing requires special roll-up test equipment (which is expensive for high speed digital), makes signal integrity difficult to maintain in the connections to the Unit Under Test (UUT), and forces the choice of accepting inadequate testing or designing custom hardware with associated expenses and long term maintenance challenges. In this paper, I identify some of the fundamental problems with traditional digital test equipment and propose a solution that is cost effective and gives capabilities that previously required custom hardware design to realize.