METHOD FOR IDENTIFYING ADDRESS PART AND CONTROL PART IN PROTOCOL CONVERSION

摘要

PURPOSE:To standardize discriminating operation by allowing a data receiving circuit to share the discriminating registers of the address part and control part. CONSTITUTION:High-level data link control consists of a constant format frame, i.e. the address part A following a frame synchronizing signal, the control part C, an information I, a frame inspection sequence FCS, and a flag sequence F. The address part A can be expanded to optional bytes, but the address part A can be discriminated so as to send expansion data together at the same time. Then the address part A and data on the control part C which is sent next are sent to shift registers 5 and 11 in order and the address part A and control part C are discriminated on every one-byte shift. Namely, the format of the frame is fixed, so the control part C is only discriminated after the address part A is discriminated; and the registers 5 and 11 for discriminating between the both can be used in common. Consequently, the discriminating operation can be standardized.