Patent ID: 7289615
Filing Date: 2007-10-30
Classification: H04Q

Abstract:
1. A private branch exchange (PBX) comprising: (a) a main control unit for working as a central processing unit (CPU); and (b) a plurality of line cards, and each one of said line cards including: wherein said main control unit recognizes types and numbers of said line cards at startup of the PBX for predicting a load applied to a system, and the prediction prompts said main control unit to determine which one of said main control unit and said sub-control unit controls which individual module of the first and the second module groups on each one of said line cards, wherein when a module to be accessed is directly controlled by at least one of said main control unit and said sub-control unit, the access bypasses said bus arbitration circuit, and wherein when the module to be accessed is controlled by both of said main control unit and said sub-control unit, said internal module bus selecting unit carries out a process using said bus arbitration circuit.