Memory management unit (MMU) in an application processor responds to an access request, corresponding to inspection request, including target context and target virtual address and the inspection request is for translating the target virtual address to a first target physical address. The MMU includes context cache, translation cache, invalidation queue and address translation manager (ATM). The context cache stores contexts and context identifiers of the stored contexts, while avoiding duplicating contexts. The translation cache stores first address and first context identifiers second addresses, the first address corresponds to virtual address, the first context identifiers corresponds to first context, and the second addresses corresponds to the first address and the first context. The invalidation queue stores at least one context identifier to be invalidated, of the context identifiers stored in the translation cache. The ATM controls the context cache, the translation cache and the invalidation queue.