Digital trunk circuit supporting multiple trunk circuits

This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application entitled Digital Trunk Circuit Supporting Multiple Trunk Circuits earlier filed in the Korean Industrial Property Office on the 13th day of July 1998, and there duly assigned Serial No. 28129/1998, a copy of which is annexed hereto. A digital trunk circuit supporting multiple trunk circuits assembled in a single board. A trunk selector capable of being operated by a user, outputs trunk select information for selecting one of the multiple trunk circuits according to an operation of the user. A read only memory (ROM) stores drive programs for the respective trunk circuits. A framer and line interface serves as a Tframer or an Eframer according to a register value, and includes line interface nodes having a connection for the Tframer or the Eframer. A receiving transformer connected to an office line, receives a signal incoming from the office line. A transmission transformer connected to the office line, transmits a signal to the office line. A relay switch including a plurality of relays connected between the receiving transformer and the line interface nodes of the framer and line interface and between the transmission transformer and the line interface nodes, provides a receiving path between the line interface nodes and the receiving transformer and a transmission path between the line interface nodes and the transmission transformer, in response to relay drive control signals. A first processor determines a trunk circuit to be driven depending on the trunk select information output from the trunk selector, drives an associated drive program stored in the read only memory according to the determination result, generates a register value for determining an operation mode for a framer of the framer and line interface to provide the generated register value to the framer and line interface, and generates the relay drive control signals to provide the generated relay drive control signals to the relay switch.