A multi-core LSI with improved stability of operation. The multi-core LSI includes a plurality of CPUs coupled to a first shared bus, one or more modules coupled to a second shared bus, a shared bus controller coupled between the first shared bus and the second shared bus for arbitrating access to the module(s) by the CPUs, and a system controller that monitors whether or not a response signal to an access request signal of the CPUs is output from a module to be accessed, wherein the system controller outputs a pseudo response signal to the first shared bus via the shared bus controller to terminate access by the CPU while accessing if the response signal is not output from the module to be accessed after the access request signal is output to the second shared bus from the shared bus controller and before a predetermined time elapses.