A PID controller module tightly-coupled on a processor datapath

Control systems are widely used in several industrial applications fields. The most traditional control system, the Proportional, Integrative and Derivative (PID) controller, has long been implemented through several different technologies. In the last two decades, the widespread use of Field Programmable Gate Arrays (FPGAs) led to the development of several dedicated digital hardware PID modules. The integration of such modules on Systems-on-Chip typically attaches PID modules to softcore microprocessors by hanging the former on a peripheral bus which causes area and power overhead. This paper presents a PID module tightly-coupled on a processor datapath. The integration of the system with the processor is described and a test case is presented. Results show the performance levels of FPGA PID controller designs and the advantages of fine-grained customization on system design.