This kind of question is very unlikely to have come from nowhere, it looks more like you got to this point without having paid attention to your digital circuits and microprocessors lessons.
You are being given a developed application and need to replace the many logic gates for a single Read Only Memory and access each address using filp-flops, but you need to know or figure the operation of the original circuit and burn the ROM in such way that it performs the same as your combinational circuit.
You skipped a lot of lessons, and this is something I can't help you with, since I'm myself not skilled in microprocessor systems, when I need to automate something I still use logic gates, or if the application is more complex, I use PLCs, OITs, Motion controllers or whatever is readily programmable.
There are people here who are proficient in such systems, but they will ask you the schematics of your combinational and/or a flowchart.
No hay conocimiento ni herramienta que sustituya al sentido comun.