KR100228790B1 - Digital keyphone controller - Google Patents

Abstract

A controller suitable for the digital keyphone main unit switches the encoded voice data and the signaling data applied through the input highway at a predetermined communication rate, and transmits the multiple tones provided from the internal tone memory to the output highway when transmitting multiple tones. A time switch and conference means for authorizing and in charge of conference communication functions between the talkers; Multiple tone generating means connected to said time switch and conference means and having a step value memory internally for providing multiple tones on said input highway; Multi-tone detection means connected to the time switch and the meeting means, the multi-tone detection means for detecting a multi-tone applied from the input highway through a filter having a variable coefficient and providing it to the input highway; At least a multi-link control means internally coupled to the input highway for data communication between the main and expansion devices of the system and providing a multi-link control signal on the output highway.

Description

Controller for digital key phone main unit

1 is an overall block diagram of a controller for a digital key phone main apparatus of the present invention.

FIG. 2 is a detailed block diagram of the time switch and the conference unit in FIG.

3 is a detailed block diagram of a tone / DTMF generator in FIG.

4 is a flowchart of tone / DTMF detection according to the present invention.

5 is a detailed block diagram of a data link controller in FIG.

6 is a data format diagram applied to the present invention.

The present invention relates to a communication system, and more particularly to a controller suitable for a digital key phone main apparatus.

The main trend of modern key phone systems is the digitalization of the system. As a result, the world's telecommunications components makers are struggling to develop and sell components of digital key phones (or exchangers). In addition, system developers implement the entire system using these component devices to reduce the cost of performance improvement due to digitalization.

The essential requirement for the implementation of such a digital key phone system is, above all, the cost reduction of major components, and the cost reduction and performance improvement of the entire system based on this.

In the past, cost savings in this area were primarily the simple replacement of communication components. Therefore, although some success has been achieved in the domestic production of major parts, it is still inadequate to perform the enhancement of performance and function while one-chip the major parts of the digital key phone system. Accordingly, there was a problem that the international competitiveness of the key phone system market was not properly established.

Accordingly, it is an object of the present invention to provide a controller for a digital key phone main unit which can solve the above-mentioned conventional problems.

Another object of the present invention is to provide a controller device for a main unit of a private exchange system which can be mounted on one chip and has improved performance.

According to an aspect of the present invention for achieving the above object, the controller device of the digital switching system having an input and output highway: switching the encoded voice data and signaling data applied through the input highway at a predetermined communication rate, A time switch and conferencing means for applying the multiple tones provided from an internal tone memory to the output highway when the multiple tones are transmitted, and responsible for conference communication function between multiple speakers; Multiple tone generating means connected to said time switch and conference means and having a step value memory internally for providing multiple tones on said input highway; Multi-tone detection means connected to the time switch and the meeting means, the multi-tone detection means for detecting a multi-tone applied from the input highway through a filter having a variable coefficient and providing it to the input highway; At least a multi-link control means internally coupled to the input highway for data communication between the main and expansion devices of the system and providing a multi-link control signal on the output highway.

Hereinafter, the structure of a controller for a main apparatus according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, detailed descriptions of the type of such structures and the like are provided to aid in a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be implemented by the above-described technical spirit of the present invention without such details. In addition, the well-known features and functions of the base element are not described in detail in order not to obscure the present invention.

First, referring to FIG. 1 implemented according to the present invention, the controller for the digital keyphone main unit includes a time switch and a conference unit 100, 101, a tone generator 200 for generating multiple tones, a tone detector 300 for detecting multiple tones, and a high level. HDLC1 for data link control, 2 400, 410, and IPC 420 for interprocessor communication. In addition, the controller includes a decoding and control unit 510 for performing address decoding and interrupt control for controlling the entire system, and a clock generator 500 for generating a clock. The highway in FIG. 1 represents a stream of input / output data, via the time switch 100. In addition, the input highway is commonly connected to the input terminals of the time switch 100, the conference unit 101, the tone detector 300, and the HDLC1, 2 400, 410. The output of the tone generator 200 is connected to the input highway. The outputs of the HDLC1, 2 400, 410 are connected to the output highway. The output of the decoding and control unit 510 is connected to the HDLC1, 2 400, 410, IPC 420, tone generator 200, and conference unit 101. In FIG. 1, detailed circuit blocks of the time switch and the conference units 100 and 101 are shown in FIG.

First, with reference to FIG. 2, the configuration and operation of the time switch and the conference units 100 and 101 will be described below. In general, an exchange method widely used in a system that performs an exchange function such as a digital keyphone or an exchanger is implemented using a T-switch chip as a time division switching method. In addition, one of the services provided by the exchange system is a conference function for simultaneous calling of three or more subscribers, which is implemented using a digital conference call chip. In the present invention, while implementing the above two functions in one chip to share a large portion to obtain the effect of lowering the overall cost (Cost). In FIG. 2, the time switch and the conference units 100 and 101 are: serial / parallel converter 2, multiplexer 12, speech memory 4, conference memory 22, conference adder and subtractor 8, bottle / serial converter 14, interface 16, control memory 18 And a signal memory 24, a tone memory 26, an address generator 20, and parts 6 and 10 for compressing and decompressing the voice PCM data. In FIG. 2, the serial to parallel converter 2 converts input data applied through a highway into formatted parallel PCM data and outputs each through a line. Here, the main functions of FIG. 2 include 288 × 256 channel switching, 4-step gain control, 8-way 6 group digital conference, A-law / ??-law support, 32-channel message mode, and Ti-. Mode & Stand-Alone Mode. The principle and operation of the time switch configured as shown in FIG. 2 will be described. A widely used time division multiplexing scheme, input signals of multiple channels are multiplexed in time and input through a single TDM link (commonly called a highway in a switching system). One TDM link carries a total of 32 channels of PCM data sampled at 8KHz. In time division multiplexing, the input highway performs an exchange function by changing the position of each channel in time.

In order to implement the principle of this method, the voice signals of the subscribers that enter through the input highway are stored in the memory of a specific address by using a memory such as RAM, and the output highway is stored in the memory corresponding to the channel to be switched. The existing data will be read and exported. According to FIG. 2, non-blocking switching is possible up to 256 channels at a rate of 64 Kbps / channel, and is allocated to a channel for a common resource for tones using 32 bytes of additional memory. This prevented the limitation of the number of subscriber lines.

In FIG. 2, the description of the digital conference function is as follows. Conferencing is a function that allows three or more users to talk to each other at the same time. In order to implement this function, a function of synthesizing two or more voice data in addition to a simple switching function is required. The digital conference function requires the function of converting PCM input data into linear data for synthesizing voice data, and a control part for determining a conference group, conversion between an internal data format and an input / output highway data format. For this, a S / P converter, a P / S converter, and an arithmetic processor for finding the difference between voice data are needed. To this end, reference numeral blocks 2, 4, 4, 6, and 22 in FIG. 2 operate in conjunction with each other.

FIG. 3 shows a concrete block of the tone generator 200 in FIG. The tone generator 200 of FIG. 3 includes a step value setting unit 210, an address generator 220, a sine table 230, a gain control 240, and a PCM compressor 250. The generator 200 solves problems of existing tone generators as a part for generating a tone used in a key phone system. That is, in the related art, when a tone frequency needs to be changed, a memory EPROM having tone data needs to be replaced, and a general tone and a digit tone have to be distinguished from each other. In the present invention, when the tone frequency needs to be changed by using the step value setting unit 210, the frequency can be easily changed even in the on-line state by changing the step value according to the frequency value. In addition, by inputting the frequency value of the tone to be used without distinction between the normal tone and the digit tone, the PCM code value of the corresponding frequency is generated and output to the designated channel. The tone data generated by the tone generator 200 is connected to a separate channel to an input portion of the time switch so that the number of subscriber lines is not affected. That is, the digit transmission function can be executed by connecting the digit to be used on the time switch to the channel to be transmitted for a desired time. The operation according to FIG. 3 is as follows. First, the CPU writes the value of the frequency to be generated in the step value RAM 210. The address generator generates a 9-bit address by calculating an address of a sine table ROM according to 8 KHz with the frequency value read from the RAM 210. Here, the sine table ROM 230 has a value of a sine function adjusted to a maximum value of 0.6 dB. As shown in the output address of the address generator 220, the sine value from the table 230 is applied to the gain control unit 240 to perform gain adjustment of a value corresponding to the control of the CPU. The gain-adjusted tone data is compressed by the PCM compressor 250 and then provided to the tone memory of the time switch unit.

4 shows a concrete block of the tone detector 300 of FIG. 4 includes a serial / parallel converter 401, a PCM expander 402, an energy checker 403, a time checker 404, a twist checker 405, and a tone recognizer generator 406. Here, the detector 300 of FIG. 4 is a module for detecting the tones used in the keyphone system, and has a slightly different point from the existing tone detector. That is, by inputting a coefficient of the band pass filter BPF corresponding to the frequency to be detected, all frequencies included in the voice band can be detected. In other words, both DTMF and tone can be changed to meet the requirements of the world. Conventional general tone detectors output results for frequency detection in a certain band and output results for detection of a specific frequency. In both cases, the frequency to be detected cannot be changed. However, the tone detector 300 of FIG. 4 can be modified without changing hardware by programming the detection frequency. In addition, the coefficient value can be changed on-line. The description of FIG. 4 is as follows. First, DTMF or tone serial PCM data input from the highway is converted into 8-bit PCM data every 125usec through the S / P converter 401. For internal calculations, the PCM data is converted back to 16-bit linear data by the expander 402. Using this linear data, the bandpass filter calculates all possible frequency components specified by the CPU to detect specific frequencies. In the case of DTMF, it compares the total energy with the top 2 frequency energy components with all possible frequency components and checks the duration and disconnection time of the top 2 frequency energy components, and the twist of the top 2 frequencies. (Valid Tone) will be determined. For this purpose, blocks 403, 404, and 405 of FIG. 4 exist. Here, the tone has two cases of dual tone and single tone, and in the case of dual tone, the total energy and the top two frequency energy components are compared with all possible frequency components, and the duration of the top two wave energy components, and the top two frequencies, respectively. Check the twist of to determine the effective tone. In case of single tone, only the top 1 is used for the above processing. The overall main functions of FIG. 4 are tone / DTMF selection, simultaneous four channel detection, single / dual tone detection, and on-line change of the detection frequency of a specific channel.

In FIG. 1, concrete blocks of data link controllers 400 and 410 that control high level data are shown in FIG. 5 includes a CPU interface 401, a transmit pico memory 402, a decoding and control unit 403, a receive pico memory 404, a transmit logic 405, an interrupt control unit 406, a receive logic 407, and a transmit and receive flag / circuit check generator 408, 409. . The entire module of FIG. 5 is a controller applied to a link used for data communication between a base rack and an expansion rack in the system of the present invention, and uses its own link protocol and uses two identical modules. Have. Depending on the mode setting, 64KBPS, 128KBPS, 256KBPS data transmission and reception are possible. The data link controller has two identical modules as shown in FIG. 5 and is connected to each highway. In the case of transmission, transmission data is stored in the Tx Pico 402 according to the frame format through CPU control, and then transmission is started to the highway through CPU control. In the case of reception, the CPU reads the reception data from the Rx packet 404 by looking at the contents of the status register according to each state of the reception data. 6 shows the frame format performed by the data link controller. F of reference numerals 601 and 602 denotes a sync flag, and is composed of 1 byte, which indicates the start of a frame. S of the reference numerals 603 and 604 is composed of one byte and is a bit representing the length of the entire frame, that is, the number of bytes. Information of reference numeral 605 is a portion in which data to be transmitted is actually loaded, and is a maximum of 58 bytes. CRCs of reference numerals 606 and 607 are frame check sequence bits used for error correction, and are allocated by 1 byte. Here, the generation polynomial of the CRC is given by G (x) = x ¹⁶ + x ¹² + x ⁵ +1.

Therefore, various advantages of the ASIC of the digital key phone controller are described as follows. That is, in the prior art, the number of subscriber lines was limited by separately assigning highways for transmission of conference and tone data. However, in the present invention, the present invention can be shared without allocating a separate highway for transmission of conference and tone data. By devising a structure there is an effect that the above conventional disadvantages are eliminated. In addition, signaling between systems allows for direct signaling by placing a separate signal memory in the time switch. Solving the conventional problem that EPROM had to be replaced to change the tone frequency, the frequency change was made easy by simply downloading the desired frequency from the CPU. The tone detector can also detect all frequencies in the telephone line band and improves the system's operational flexibility by using a digital signal processor. In addition, the data link controller is a proprietary protocol, which is a byte-oriented format, capable of multi-frame transmission, and in particular, the existing data link controllers have only a large capacity of information within 20 bytes. A high speed data link controller is implemented.

The cost saving effect of the bar as described above also appears in the tangible part, but there is a significant effect in terms of intangible aspects, such as securing reliability, acquisition of difficult technology, reduction of manufacturing defect points, and securing of core parts.

As described above, the controller according to the present invention also has the advantage that the entire system is compact since it is implemented in one chip.

Claims (7)

A controller device of a digital communication system having an input / output highway, comprising: memory means for storing voice, call switching, conferencing, and tone data respectively applied through the input highway, and converting the data into parallel data and converting the converted data into a parallel data; The contents of speech memory in the memory means for time division multiplexing means and, if the tone data is transmitted, provide a tone to the output highway instead of the voice data and store the voice data provided from the multiplexing means. In the case of belonging to the conference group, the voice data of the corresponding channel is added and the channel data is subtracted from the summed value, and the voice data provided from the subtraction means is demultiplexed and serially converted and provided to the output highway. A time switch comprising means And conference means; Multiple tone generating means coupled to said time switch and conference means and having a step value memory internally for providing multiple tones on said input highway; Multi-tone detection means connected to the time switch and the meeting means, the multi-tone detection means for detecting a multi-tone applied from the input highway through a filter having a variable coefficient and providing it to the input highway; An apparatus having a pair of modules internally for data communication between a main unit and an expansion unit of the system, the apparatus comprising at least multi-link control means for providing a multi-link control signal on the output highway; . 2. The apparatus of claim 1, wherein the time switch and conferencing means are mounted on the same chip and perform at least 288 × 256 channel switching and 8 way 6 group digital conferencing. 2. The method of claim 1, wherein the tone data generated by the multi-tone generating means is provided as a separate channel to the input highway of the time switch and the conferencing means to systematically prevent the reduction of the number of subscriber lines in the input highway. Device characterized in that. The method of claim 1, wherein the multi-tone detection means has the ability to perform simultaneous four-channel detection and single / dual tone detection, characterized in that configured to enable the on-line change of the detection frequency for a particular channel. Device. A controller device of a digital switching system having an input / output highway, the controller device comprising: switching the encoded voice data and signaling data applied through the input highway at a predetermined communication rate, and the multiplexing provided from an internal tone memory during transmission of multiple tones. A time switch and conferencing means for applying a tone to said output highway, said time switch being responsible for conferencing communication function between the talkers; Multiple tone generating means connected to said time switch and conference means and having a step value memory internally for providing multiple tones on said input highway; Multi-tone detection means connected to the time switch and the meeting means, the multi-tone detection means for detecting a multi-tone applied from the input highway through a filter having a variable coefficient and providing it to the input highway; An apparatus having a pair of modules internally for data communication between a main unit and an expansion unit of the system, the apparatus comprising at least multi-link control means for providing a multi-link control signal on the output highway; . A control method of a digital switching system having an input / output highway, the control method comprising: switching encoded voice data and signaling data applied through the input highway at a predetermined communication rate, and the multiplexing provided from an internal tone memory during transmission of multiple tones. Applying a tone to said output highway and performing a conference communication function between the talkers; Accessing a step value memory internally to provide multiple tones on the input highway; Detecting the multiple tones applied from the input highway through a filter having a variable coefficient and providing them to the input highway; Providing at least a multilink control signal on said output highway. CLAIMS 1. A method for preventing subscriber line limitation in a digital key phone system, comprising: sharing tone data through a tone memory; When the tone data is shared, a process of storing a plurality of subscriber voice signals received through an input highway in a specific address storage location, and reading data of a storage location corresponding to a channel to be switched and outputting them as a voice signal through an output highway Characterized by consisting of a process.