Patent ID: 7111107

Claim:
A microcontroller with expandable memory banks, the microcontroller comprising: a microprocessor; a plurality of memory banks connected to the microprocessor for storing data, programs; a memory bank control circuit connected to the microprocessor for asserting a signal during the processing of an interrupt event; and a multiplexer for connecting the microprocessor with the plurality of memory banks, the multiplexer comprising: a first input connected to an output of the microprocessor for bank switching during the normal operation; a second input connected to a predetermined value corresponding to the memory bank storing the interrupt service routines; and a selecting port connected to an output of the memory bank control circuit for selecting whether to output an page selection signal from the output of the microprocessor or an predetermined page selection signal, wherein the microprocessor can access data stored in the memory bank storing the interrupt service routines when the interrupt occurs.