Patent ID: 7580358

Claim:
A bidirectional communication control apparatus which is provided in a terminal apparatus which performs bidirectional data transmission/reception with respect to a center apparatus, the bidirectional communication control apparatus comprising: a first storage apparatus; a CPU bus connecting between the CPU and the first storage apparatus; a downstream data processing block of receiving downstream data transmitted from the center apparatus to the terminal apparatus, and performing data processing; an upstream data processing block of performing data processing to generate upstream data to be transmitted from the terminal apparatus to the center apparatus; a bus data arbitration processing block of regulating a flow of data on the CPU bus, the bus data arbitration processing block being connected to the CPU bus, the downstream data processing block, and the upstream data processing block; and a data processor having a register of temporarily holding data, the data processor being connected to the CPU bus, the upstream data processing block, and the downstream data processing block while bypassing the bus data arbitration processing block, wherein the downstream data processing block and the upstream data processing block perform direct data transmission/reception with respect to each other.