Patent ID: 7058777
Filing Date: 2006-06-06
Classification: G06F

Abstract:
1. A microcontroller device for extending memory address space by inserting a waiting state, wherein the device is coupled to an external memory through a bus, and the external memory has stored at least a first program, the device comprising: a read-only memory (ROM), for storing a second program; a central processing unit (CPU), coupled to the ROM for executing the first program or the second program; and a memory interface controller, for inserting a waiting state into the CPU when the CPU intends to execute an instruction of the first program stored in the external memory; wherein the memory interface controller comprises: a memory interface, coupled the bus, serving as a transmission interface between the memory interface controller and the bus; a range checking unit, used to judge whether or not an address of an information, which is to be accessed by the CPU, is located within a predetermined range, and selectively issuing a range checking signal; and a state control unit, coupled to the memory interface, the range checking unit, and the CPU, used for inserting the waiting state into the CPU when the range checking signal is received.