ISDN terminal adapter for use with external modem and employing software-based serial communication framing for ISDN `D` channel signaling

An ISDN terminal adapter for providing communication connectivity between data terminal equipment and a communication circuit, and being operative to use a customer's modem for analog connectivity with said communication circuit, comprising an ISDN communication transceiver for transmitting and receiving ISDN-formatted communication signals over said communication circuit, a first digital communication connector coupled with a digital communication port of said data terminal equipment, a second digital communication connector coupled with a digital communication port of said modem, a first analog communication connector coupled with an analog port of said modem, a first analog/digital communication interface coupled between said first analog communication connector and said ISDN communication transceiver, and a serial communication exchange processor coupled with said first and second digital communication connectors and said ISDN communication transceiver, said processor being operative, in response to a request for digital connectivity with said communication circuit, to provide a first communication path, exclusive of said modem, between said first digital communication connector and said ISDN communication transceiver, so that ISND-formatted communications may take place between said data terminal equipment and said communication circuit, and, in response to a request for analog connectivity with said communication circuit, to provide a second communication path through said modem, said first analog communication connector, said first analog/digital communication interface and said ISDN communication transceiver, so that communications may take place between said data terminal equipment and said communication circuit.

For use with data terminal equipment and an associated modem, said modem having a digital communication port for connectivity with said data terminal equipment and an analog communication port for analog connectivity with a communication network, a terminal adapter which is operative to provide communication connectivity between said data terminal equipment and either of an analog or digital communication circuit, said terminal adapter comprising:

• a digital communication transceiver for transmitting and receiving digital communication signals on a digital communication circuit;
• a first digital communication connector configured for connection with a digital communication port of said digital terminal equipment;
• a second digital communication connector configured for connection with said digital communication port of said modem;
• a first analog communication connector configured for connection with said analog communication port of said modem;
• a first analog/digital communication interface coupled between said first analog communication connector and said digital communication transceiver;
• and
• a communication processor which is operative to selectively provide one of a first serial communication path between said first digital communication connector and said digital communication transceiver, exclusive of said modem, so that digitally formatted communication may take place between said digital information processing device and said digital communication circuit exclusive of said modem, and a second communication path, inclusive of said modem by way of said second digital communication connector and said first analog communication port, so that digitally formatted communication may take place through said modem between said digital information processing device and said digital communication circuit.

For use with data terminal equipment and an associated modem, said modem having an analog communication port that is configured for analog connectivity with a POTS communication network, and a digital communication port, a method of providing digital communication connectivity between said data terminal equipment and a digital communication link for said communication network, said method comprising the steps of:

• (a) providing a digital communication transceiver for transmitting and receiving digital communication signals on said digital communication link;
• (b) connecting a first digital communication connector with a digital communication port of said user's digital terminal equipment;
• (c) connecting a second digital communication connector with the digital communication port of said modem;
• (d) connecting a first analog communication connector with the analog communication port of said modem;
• (e) coupling a first analog/digital communication interface between said first analog communication connector and said digital communication transceiver;
• and
• (f) selectively providing one of a first communication path between said first digital communication connector and said digital communication transceiver, exclusive of said modem, so that digitally formatted communication may take place between said digital information processing device and said digital communication link, and a second communication path, inclusive of said modem by way of said second digital communication connector, said first analog communication connector, and said first analog/digital communication interface, so that digitally formatted communication may take place through said modem between said digital information processing device and said digital communication link.

A method of providing data communication connectivity between a data processing device and a digital communication link for a communication network, said method comprising the steps of:

• (a) providing a digital communication transceiver for transmitting and receiving digital communication signals on said digital communication link, said digital communication transceiver having a high speed data port;
• (b) providing a serial communication exchange processor, including a plurality of serial communication controllers and an interrupt port;
• (c) providing a first communication path for conveying digital communication signals between a first serial communication controller of said serial communication exchange processor and said data processing device;
• (d) providing a second communication path for conveying a first type of data between a second serial communication controller of said serial communication exchange processor and said digital communication transceiver;
• and
• (e) conveying a second type of data between said digital communication transceiver and said serial communication exchange processor by directly coupling said interrupt port of said serial communications exchange processor to said high speed data port of said digital communication transceiver, and conducting interrupt-based data communications between said high speed data port of said digital communication transceiver and said interrupt port of said serial communications exchange processor.

An arrangement for providing data communication connectivity between a data processing device and a digital communication link for a communication network comprising:

• a digital communication transceiver which is operative to transmit and receive digital communication signals on said digital communication link, said digital communication transceiver having a high speed data port;
• a serial communication exchange processor which includes a plurality of serial communication controllers and an interrupt port which is directly coupled to said high speed data port of said digital communication transceiver;
• a first communication path for conveying digital communication signals between a first serial communication controller of said serial communication exchange processor and said data processing device;
• a second communication path for conveying a first type of data between a second serial communication controller of said serial communication exchange processor and said digital communication transceiver;
• and
• wherein said serial communications exchange processor is programmed to conduct interrupt-based data communications between said interrupt port thereof and said high speed data port of said digital communication transceiver, and thereby convey a second type of data between said serial communication exchange processor and said said digital communication transceiver.