| 摘要 |
PURPOSE: An interface selection circuit for a SOHO router is provided to select an RS-232 interface or a consol interface by an address decoding PLD in accordance with an interface selection signal from a connector. CONSTITUTION: An RS-232 transceiver(21) provides a serial communication with an external type asynchronous modem. A connector(22) provides an RS-232 interface of an external type asynchronous modem and a consol interface for a local management. An address decoding PLD(23) selects a certain interface connected with a corresponding connector(22). The address decoding PLD(23) performs an address decoding function in a SOHO router and selects an RS-232 interface or a consol interface in accordance with an interface selection signal(AHCL) from a corresponding connector(22). When an interface selection signal(AHCL) connected with the connector(22) is a high level signal, an input value of 3 is outputted as an output value of 2, and an input value of 5 is outputted as an output value of 6 for thereby providing an RS-232 interface function. In the case that a corresponding interface selection signal(AHCL) is inputted as a low level signal, an input value of 1 is outputted as an output value of 2, and an input value of 5 is outputted as an output value of 4, so that a corresponding SOHO router provides a consol interface function.
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