Reconfigurable FPGA's dual role: in-system test and system level logic

Static RAM based field programmable gate arrays (FPGAs) solve the overhead problem because they can be reconfigured in-system any number of times. This unique capability allows the same device to perform a variety of functions without increasing board space or power or sacrificing system performance. When the system is powered up, a special diagnostic configuration can be loaded into the FPGA and test vectors can be applied to the device. Once circuit and board integrity are verified, another configuration file can be loaded into the SRAM cells of the FPGA. Subsequent configuration files can contain any number of logic configurations for the device, enabling it to perform system-level functions. With some thought and creativity, any SRAM FPGA can be configured to test itself. As more and more engineers incorporate on-chip diagnostics into their FPGA designs, self-testing applications will become more sophisticated. This paper explores the dual role of reconfigurable FPGAs in-system: system level logic functions and in-system diagnostics.