MXPA99008585A - Integrated circuit for the interface of access to the telephone network lo - Google Patents

Abstract

An integrated circuit for the interface of access to the local telephone network, of digital type, for its application to telephone switching systems, usable as an intermediate element between the external modules and the local network internal to the system, is structured so that it incorporates a control central for execution of internal tasks and control access to the internal bus to the circuit, an external bus access controller, two statistical transmitters, responsible for sending frames to the local network by indication of the central control, two statistical receivers to receive frames from the local network and store them in an external memory, and a PCM switching matrix interconnected with the central control in terms of commands and answers

Description

INTEGRATED CIRCUIT FOR THE INTERFACE OF ACCESS TO THE LOCAL TELEPHONE NETWORK FIELD OF THE INVENTION The present invention relates to an integrated circuit for the access interface to the local telephone network. More particularly, the invention develops an integrated, digital circuit capable of being applied as an access interface to the local network, of the modules that constitute a telephone switching system. The field of application of the invention is comprised within the field of communications, and more specifically, within the field of communication controllers integrated in telephone switching systems.

BACKGROUND OF THE INVENTION The communication controllers, integrated in telephone switching systems, which are currently known, present as a distinctive feature the fact that they have been designed and structured to handle statistical type links, or PCM type links, but in no case case to perform both tasks together.

The most favorable practical situation would be to have a communications controller device, for its integration into a telephone switching system, which is capable of developing the functions derived from both types of links, with all the advantages that this entails. Until now, there is no knowledge of the existence of a controller that meets both mentioned characteristics. Accordingly, the main object of the present invention consists precisely in the development of an integrated circuit, whose internal architecture is structured so that it incorporates the necessary elements to be able to implement both functions together.

BRIEF DESCRIPTION OF THE INVENTION The integrated circuit recommended by the invention consists of a digital circuit, capable of serving as a means of accessing a local network (for example, of the ETHERNET type), by the modules belonging to a telephone switching system. The aforementioned local network is configured according to the following characteristics: it has a bus topology, it is synchronous transmission, it has a multiple access system with collision resolution, with HDLC link control, and with a double insertion bit for the adaptation of internal synchronism . Accordingly, the integrated circuit thus defined constitutes an intermediate element between the modules external to it and the local network internal to the system. The integrated circuit of the invention, as it has been conceived, incorporates the following elements: -1 Central control -1 External bus access controller -2 Statistical transmitters -2 Statistical receivers -1 Switching matrix PCM Each of these elements, fulfills with a predetermined function, as explained below. In effect, the central controller is responsible for executing the tasks internal to the circuit, such tasks can be ordered by modules external to the circuit, or by the remaining elements internal to the circuit; In addition, it is responsible for managing access to the internal bus of the integrated circuit. As regards the external bus access controller, it is responsible for managing the access ordered to said bus by the elements belonging to the circuit, and by the modules external to it. For their part, the two statistical transmitters are responsible for sending frames (which are stored in external memory), to the local network, after receiving the relevant order from the aforementioned central control. The statistical receivers are in charge, inversely to the transmitters, of receiving frames from the local network, and storing them in external memories obtained on request to the aforementioned central control. Finally, the PCM switching matrix consists of three PCM connections, two of which are connected to the local network, and the third is connected to an external module to the circuit.

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the invention will be apparent from the following detailed description of a preferred embodiment of the invention taken by way of illustrative and non-limiting example, with reference to the accompanying drawings, in which: Figure 1, or single figure, shows a schematic of a block diagram of the integrated circuit of the present invention.

DETAILED DESCRIPTION OF A PREFERRED MODALITY As indicated above, the detailed description of the modality will be carried out taking into consideration the example of figure 1 of the drawings, whose block diagram shows, schematically, the internal architecture of the circuit developed by the present invention. Thus, a central controller (1), a controller (2) to access the external bus, two statistical transmitters (3), two statistical receivers (4), and a PCM switching matrix (5) appear, all these interconnected elements appearing each other by means of buses and appropriate connecting lines. As explained above, the integrated circuit has been designed to operate on predetermined local networks, preferably of the ETHERNET type (bus topology and synchronous mode), belonging to telephone switching systems, and so that said circuit constitutes the access interface to the internal local networks of said systems, by means of the multiple access technique with collision resolution and double insertion bit, in order to carry out the adaptation of the frames to internal synchronism. In addition, the circuit has two clearly differentiated buses, as shown in the same figure 1 commented, referenced with the numbers (6, 7), of which the bus (6) is managed by the access controller (2), while the other bus (7), constituting the internal bus to the circuit, is managed by the central controller (1). The central control element (1) executes the tasks internal to the circuit and controls the ordered access to the internal bus (7) of the elements belonging to it. Such tasks can be ordered by the modules external to the circuit, or by the elements inside it. The central control (1) is preferably of the microprogrammed type, stored in a dedicated internal ROM memory. Among the tasks it performs, are those of transmission of frames, assignment of PCM channels, configuration of links, request of buffers, and other similar.

On the other hand, the controller (2) for accessing the external bus (6) carries out the function of managing the ordered access to said bus, both of the internal elements and of the internal elements. The statistical transmitters (3) fulfill the function of sending frames to the local network, after receiving the mandatory transmission order from the central control (1). The contents to be transmitted are extracted from an external communications memory, are monitored and, depending on the state of the link, are sent to the local network, storing the transmission statistics in an external storage area obtained by the central control (1) . Preferably, such transmitters access the local network with TTL levels, in open collector, at a predetermined speed (for example, at 2048 Kbits / s), with multiple access method with collision resolution, and with double insertion bit for adapt the frame to internal synchronism. The statistical receivers (4) receive the frames from the local network, saving the contents in areas of an external communication memory, which are obtained by the central control (1). The receiver (4) is polling the line until it detects the beginning of the frame, carries out the supervision of the frames, and generates statistics relative to the reception, storing them in an external storage area. The connection to the local network is performed, preferably with TTL levels, at a predetermined speed (for example, at 2048 kbits / s), synchronized with the group clock.

The PCM switching matrix (5) is intercommunicated, at the command and response level, with the central controller (1), and has three PCM links, of which two are connected to the local network and the third to a unit external to the circuit. Among the functions that it develops, are those of switching channels from incoming links to outgoing, putting any channel in "open collector", reading the content of any channel, and others of a similar nature. In the foregoing, a preferred embodiment of the object of the present invention has been described, sufficiently so that a person skilled in the art can understand its scope and the advantages derived from it, as well as to carry out the practical realization of its object. . However, and since it is only a preferred embodiment, it is clear that within its essential nature multiple variations of detail may be introduced, also protected, without this implying departing from the content of the invention, limited only by the scope of the invention. the claims that follow.

Claims (2)

NOVELTY OF THE INVENTION CLAIMS

1. - Integrated circuit for the access interface to the local telephone network, in particular of the digital type, belonging to telephone switching systems, designed to control the communications between the modules belonging to the system through its own internal local network , incorporating together incoming / outgoing statistical links and links of type PCM, characterized in that its internal architecture has been structured in such a way that it incorporates a set of consistent elements, preferably, in a central control (1), a controller (2) of access to the external bus, two statistical transmitters (3), two statistical receivers (4) and a matrix (5) of PCM switching, conveniently interconnected with each other, as well as an external bus (6) managed by the access controller (2) and a bus (7) internal to the circuit, managed by the aforementioned central control (1).

2. Integrated circuit according to claim 1, characterized in that it is associated with a network of predetermined characteristics (for example, of ETHERNET type), with bus topology, synchronous transmission and double insertion bit for adapting the internal synchronism , wherein said central control (1), microprogrammed, executes internal tasks of the circuit and access control to the internal bus (7); said external bus access controller (2) fulfills the function of managing the access ordered to said bus; the statistical transmitters (3) send frames to the local network by indication of the central control (1); the statistical receivers (4) receive frames from the local network and store them in an external memory obtained through the central control (1), and the matrix (5) of the PCM switching is interconnected, at command and response level, with the central control (1).