COMMUNICATION INTERFACE CIRCUIT

摘要

PURPOSE:To improve the reliability of a communication interface circuit by using two buffer circuits for emergency and normal uses and giving priority to the communication data stored in the emergency buffer circuit to execute with no delay the real time processes such as the cancel of the preceding data, etc. CONSTITUTION:A data deciding circuit 6 decides whether the communication data received by a communication interface 1 is equal to the emergency or normal communication data. The normal communication data is stored temporarily to a reception buffer circuit 2A; while the emergency communication data is stored temporarily to a reception buffer circuit 2B respectively. The stored emergency and normal communication data are transmitted to a terminal device 5 via an interruption request line INT-L and a control bus CT-BUS respectively. Then a data bus D-BUS is used to read those data. An interruption is applied for the emergency communication data to eliminate delays. Thus the modulation is prevented for the overall working of a system. This improves the reliability of a communication interface circuit.