The Facility for Rare Isotope Beams (FRIB) opened for full user operation in May 2022 and is currently prototyping a 644 MHz superconducting (SC) cavity and cryomodule for an energy upgrade of the accelerator to 400 MeV/u. The low level radio frequency (LLRF) controllers in operation are based on Xilinx Spartan 6 field programmable gate array (FPGA) and support frequencies up to 322 MHz. With requirements for higher frequency operation there was a need to upgrade the current LLRF controller. A next generation prototype controller was designed, developed and fabricated using Xilinx Zynq System on Chip (SoC) FPGA with high-speed JESD204 serial interface to fast 14-bit analog to digital (ADC) and 16-bit digital to analog (DAC) data converters and capable of high frequency direct sampling. A brief overview of the prototype LLRF controller, its features, improvements along with Experimental Physics and
Industrial Control System (EPICS) Input/Output Controller (IOC), fast data capture at native resolution, remote update management implementation and future projects will be discussed in this paper.