| 摘要 |
PURPOSE: A subscriber interface circuit in a wireless local loop(WILL) terminal and a method for designing the circuit are provided to implement the WILL terminal with a low cost and power consumption, using only a four-channels CODEC and a subscriber line interface circuit(SLIC), thereby enable an interface with a peripheral logic by 3.3V and reduce the size of the terminal. CONSTITUTION: A four-channels CODEC(10) passes voice data to SLICs(20,30,40). The SLICs(20,30,40) are connected to the four-channels CODEC(10) and thereby provide all functions necessary for a telephone line interface. The SLICs(20,30,40) convert a digital instruction signal from a base station to a corresponding function, and are controlled by signals(D1,D2,D3) from the CODEC(10) to be interfaced with a transmission and reception pins by a pulse code modulation. The CODEC(10) and SLICs(20,30,40) perform the functions such as a line state monitoring, ring generation, conversion of the voice data. A/B interfaces(50,60,70) are connected respectively to the SLICs(20,30,40) and protect lines.
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