CIRCUIT OF MODEM

PURPOSE: A circuit of a modem is provided to smooth the transceiving of data between different lines by allowing connections in various signal methods. CONSTITUTION: In a circuit of a modem, a modem controller(21) processes and delivers data corresponding to the transceiving timing between a serial...

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Bibliographic Details
Main Author LEE, MYEONG GYU
Format Patent
LanguageEnglish
Korean
Published 07.05.2001
Edition7
Subjects
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION
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Summary:PURPOSE: A circuit of a modem is provided to smooth the transceiving of data between different lines by allowing connections in various signal methods. CONSTITUTION: In a circuit of a modem, a modem controller(21) processes and delivers data corresponding to the transceiving timing between a serial or parallel interface and a modem(22). The controller(21) also controls the operations of all other parts(24,26,27,28,29,30,32). A memory(23) stores a program needed to operate the whole circuit. The modem(22) modulates digital data into analog data or demodulates analog data into digital data between the modem controller(21) and a PSTN via first and second impedance matchers(25,31). A DTMF generator(24) generates a DTMF signal and sends the signal to the PSTN. A loop resistance/dial pulse generator(26) makes an OFF HOOK status and sends a dial pulse to the PSTN. A ring detector(27) detects a ring signal from the PSTN. The first and second impedance matchers(25,31) conduct an impedance matching with the PSTN. A ring generator(28) generates a ring signal and sends the signal to the PSTN. A polarity inverter/detector(30) detects sends a polarity-inverting signal to the PSTN responding to a final private switch.
Bibliography:Application Number: KR19990042912