PROGRAMMABLE COMMUNICATIONS CONTROLLER

摘要

A programmable communications controller having a microcomputer system for buffering and controlling data communications between a communication processor and a plurality of input/output (I/O) ports of the microcomputer system to which ports/terminals can be connected directly, or indirectly, by digital data communication lines. The random access memory of the microcomputer system is divided into blocks of addresses of locations in which digital data can be stored One of these blocks is designated as a service block. The service block in turn is divided into sectors, one for each I/O port to which is connected a communication line, for example. Each sector in the service block is adapted to have written into it and read from it data unique to the servicing of a given communication I/O port and the communication line or data terminals connected to that port. The microcomputer system of the controller is provided with an automatic addresser which is under the control of the microcomputer system. The automatic addresser steers memory commands addressed to the service block to the sector of the service block assigned to the communication I/O port being serviced by the microcomputer system at that time by substituting the address of the communication I/O port being serviced for the address applied to the sector address lines of the address bus by the microcomputer system. The automatic addresser also steers, in a similar manner; I/o commands from the microcomputer system to the communication I/O port being serviced by the microcomputer system at that time by substituting the address of the port being serviced for the address of whatever I/O port is applied to the address lines of the microcomputer system.