An interrupt controller coupled to a plurality of processors is provided to rout at least one interrupt request event to at least one of the processors. The interrupt controller includes a receiving circuit and a controlling circuit. The receiving circuit receives at least one interrupt input, and the controlling circuit, generates the at least one interrupt request event based on the received at least one interrupt input and routes the at least one interrupt request event generated to the at least one of the processors. The plurality of processors including at least a first processor and a second processor, the first and second processors arranged to process interrupt request event(s), and the controlling circuit is arranged to withdraw/cancel assertion of an interrupt request event that has been transmitted to the first processor. The interrupt controller has stable and better efficiency under serious status that the procesor, in certain time, is busy or is unavailable, thus effectively improving efficiency and stability of the system.