COMMUNICATION CONTROL EQUIPMENT

PURPOSE:To cope with the revision or addition of a communication control function flexibly by executing the communication function of a high-order level according to the system control program of a semi-fixed storage means and a communication control program transferred from a host device in the case of initializing. CONSTITUTION:In the initializing state, a processor 106 of a communication controller 100 sends a program transfer request to an operation controller 202 via a control line of a port 1 according to the control of a system control program of a ROM 108. A buffer control circuit 120 of the communication controller 202 stores once the program and data into a buffer 104. A processor 108 reads a communication control program from a buffer 104 according to the instruction of the system control program of the ROM 108 and stores it in a variable program storage area 302 of a RAM 110. The function having the possibility of revision or addition in the function is stored in the RAM 110 in this way.