The Programmable Logic Controller (PLC) market is mainly dominated by Omron, Schneider, NEC and other foreign manufacturers. The CPU module of their PLC products usually has two processors at PCB level. One of the processors is general-purpose processor and the other is Ladder Chart Hardware Process Unit (LPU). Based on the research of dual-core mutual exclusion, interrupt management and data consistency issues of the LEON2 of Gaisler Research, the LPU processor and LEON2 processor are integrated in a chip on mutually exclusive SOC (System On Chip) architecture. It is proved by simulation that the PLC SOC controller works steadily and efficiently.