Porting of Open Core Processor to FPGA based CPU Module of custom DAQs of FBRs

Data acquisition & Control Systems (DAQs) are generally designed with microcontrollers, microprocessors, and System On chips (SoCs). These processors & SoCs keep evolving with time and market requirements. The DAQs being used for nuclear reactors are targeted to last for multiple decades. Hence the designs should be dependable and in case of failure being detected by exhaustive diagnostics routines, it should be easily maintainable and replaceable. With this requirement the DAQs are designed with generic components and sufficient de-rating. With the current evolution of technology getting a microcontroller for such a long design life is not possible, so for nuclear environments the microcontrollers are chosen such that they are available from multiple vendors and sufficient stock is kept to maintain systems. In spite of this, the component obsolescence hinders smooth maintainability of the systems. For overcoming such issues, the designs are done using generic programmable components like FPGA and other generic analog devices. These FPGAs also become obsolete quite often but, the RTL designs are portable for the upcoming generations of devices leaving no impact on application software or RTL design and hence the overall verification & validation efforts are minimized. Usage of FPGA also helps in porting other digital logic (glue-logic) of the embedded systems onto a single device which reduces dependency on multiple vendors. Towards this goal, the porting and implementation of open core soft-processor along with glue logic on FPGA for one of the DAQs designed for FBRs is described in this paper.