KR100259055B

PURPOSE: An Internet telephone access circuit in a private exchange is provided to execute telephone calls through Internet in a private exchange itself. CONSTITUTION: A microprocessor(210) controls the overall operations of an Internet telephone access circuit. The first memory(211) stores a control program to control the operations of the Internet telephone access circuit. The second memory(212) is a non-volatile memory. The third memory(213) temporarily stores a CELP(Codebook Excited Linear Prediction)-coded data frame. An Internet controller(221) controls an Internet line driver(225) and transmits data to Internet. An interrupt controller(231) transmits an interrupt signal to the microprocessor(210) if CELP coding frame data are generated from a CODEC part(250). A DMA controller(241) transmits a CELP coding data frame to the third memory(213). The CODEC part(250), receiving a CELP-coded signal from the Internet controller(221), converts it into a PCM-coded signal and transmits the converted signal to a time switch. A FIFO(260) transfers a signal processing message with a main processing module. A UART(270) monitors the status of the Internet telephone access circuit through an MMC monitor connected through an RS232C driver280.