JP2002237866A - Semiconductor device controlling cable modem, cable modem apparatus and method for controlling cable modem - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely process information relating to setting and operation of a cable MODEM apparatus and to provide speech communication service at the same time by VoIP technique, in a cable MODEM apparatus to be connected with a CATV network. SOLUTION: A cable MODEM controller LSI 9 which is used for the cable MODEM apparatus 1 has internal buses 15, 16. A MAC layer 12 transmits and receives a MAC frame to and from an external bus I/F 14 and an I/F 19 for PC connection via the internal bus 15. A processor 17 for processing a digital signal transmits and receives speech information to and from the external bus I/F 14 and an I/F 18 for speech communication, via the internal bus 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a cable modem device connected to a CATV network, and more particularly to a semiconductor device for controlling a cable modem.

[0002]

2. Description of the Related Art In recent years, Internet connection services have been started by CATV operators, and have attracted attention due to features such as high speed data communication, low cost of use, and constant connectivity. This Internet connection service provides asymmetric two-way data communication using the existing CATV network as it is. That is, in this data communication, a normal T
In the distribution of V-video or the like, a narrow band on the low frequency side which is not used for upstream data transfer (called Upstream) and a wide band on the high frequency side is used for downstream data transfer (Downstream).
m) so as not to interfere with each other.

As shown in FIG. 2, in order for a subscriber to actually perform data communication with other devices connected to the Internet 20 using the CATV network 23, the subscriber A
It is necessary to install the cable modem device 1 in the home 24 of the customer or in the office 25 of the subscriber B. This cable modem device 1 is composed of a head-end modem device 22 installed in a station by a CATV operator 21 and a subscriber's information communication terminal device 26.
, And is generally a subscriber's information communication terminal equipment 2
As 6, a personal computer (hereinafter abbreviated as PC) is used. The head-end modem device 22 and the cable modem device 1 are connected by a coaxial cable 2 or the like, and the cable modem device 1 and the information communication terminal device 26 of the subscriber are connected to each other by an Ethe such as 10BASE-T.
rnet27 and other general-purpose interfaces such as USB and PCI buses.

Next, a configuration of the conventional cable modem device 1 and a mechanism for performing data communication will be described with reference to FIG. First, Downst received by the cable modem device 1
headend modem device 2
An analog signal that has propagated through the cable 2 from the cable 2 via the CATV network 23 is received by the filter unit 3 and subsequently selected by the tuner unit 4 (to extract a desired frequency band). Next, the selected signal is converted into digital data, and the demodulation unit 10 performs demodulation processing. The demodulation unit 10 further performs a code error correction process on the demodulated signal to restore a transport stream conforming to the MPEG2 standard. Then, a MAC (Media Access Control) frame related to data communication is extracted with reference to the PID of the transport stream, and finally output to the MAC layer unit 12. MAC
A frame is a frame exchanged between MAC layers. The MAC layer belongs to the data link layer.
In the OSI model, the MAC layer is positioned in the lower sublayer of the data link layer, and the LLC (Logical Link
Control) to realize the data link layer function. Here, the MAC layer unit 12 determines whether the MAC frame is data addressed to the cable modem device 1 itself or data addressed to the subscriber's PC, and in the former case, the MAC frame And performs processing related to the setting and control of the cable modem device 1. In the latter case, the MAC frame is transferred from the data bus 30 to the PC connection I / F (interface) unit 1.
9 to perform bridging to the subscriber's PC. Although the MAC frame described above may be processed by special dedicated hardware, it is generally used by the CPU 5.
The processing is performed by executing a software program stored in the RAM 6 or the ROM 7.

On the other hand, the U transmitted by the cable modem device 1
In response to the data of the pstream, the cable modem device 1 receives the data transmitted from the subscriber's PC by the PC connection I / F unit 19. Next, based on the time slot information given in advance as Downstream data from the head-end modem device 22, a TDM for arriving at the head-end modem device 22 at an appropriate time is determined.
A (Time Division Multiple)
Access) control is performed. Headend modem device 2
The data for which the transfer time to 2 has been determined is subjected to modulation processing by the modulator 11 and further converted to analog data. This analog signal is transmitted from the cable 2 to the CATV network 23.
And transmitted to the head-end modem device 22.

[0006] As described above, the cable modem device 1 is composed of many LSIs that execute various processes. However, in recent years, the demodulation unit 10, the modulation unit 11, the MAC layer unit 12, and the M
There is a tendency that the functional units of the CPU 5 for processing the AC frame by the software program and the PC connection I / F unit 19 for connecting to the subscriber's PC are integrated and realized as one system LSI as one chip. By realizing a large-scale system function with one LSI, the number of components is reduced to save space and reduce costs. Further, by providing such a one-chip LSI, the construction of the cable modem device 1 is facilitated and the cable modem device 1 can be put on the market early.

On the other hand, with the emergence of such a high-speed and low-cost access environment to the Internet through the CATV network, the provision of new applications and services using the Internet is accelerating. In a cable modem device, a subscriber uses browser software or the like on a PC to view information on the Internet or exchange e-mails. In addition to data communication mainly using character information, VoIP (Voice) is used.
Voice communication function using Over Internet Protocol (IP) technology, IPSec (Internet)
There is a demand for providing a function of authenticating with a communication partner and a function of protecting communication data using a protocol security (Protocol Security) technique. Therefore, in order to respond to such an application request, the cable modem device 1 shown in FIG.
In addition to the voice communication I / F unit 18, the CPU 5 for handling MAC frames also performs voice communication processing,
A digital signal processing processor 17 which is good at operations required by the IP technology or the IPSec technology is separately provided.

[0008]

The CATV network has a tree-like network configuration. One head-end modem device installed in a CATV business provides video, music, etc. to thousands to tens of thousands of subscribers. Has been delivered. In order to smoothly perform data communication using a network of such a form, various information is exchanged between the head-end modem device and the cable modem device at all times regarding rules regarding communication, transfer delay, and the like. Then, the cable modem device 1 must dynamically respond to such information before communication or even during communication. For example, time slot information for TDMA in which the cable modem device 1 accesses Upstream is called a MAP message, which is periodically sent from the head-end modem device as Downstream. This is important information for the cable modem device 1 to transmit data at an appropriate time, and is given to the cable modem device when the analysis of the MAP message is delayed or a lot of time is spent. Data cannot be sent at the transfer opportunity. Information relating to such basic operation of the cable modem device needs to be processed with the highest priority. However, when the cable modem device also has a voice communication function based on the VoIP technology, it is necessary to perform processing such as compression, reproduction, and packetization of voice data. In the case where the digital signal processing processor 17 is not provided in the cable modem device 1 shown in FIG. 3, since all the processes must be executed by the CPU 5,
Depending on the performance of the CPU 5, it may not be possible to cope with it. When the digital signal processing processor 17 is provided, the CPU 5 and the digital signal processing processor 1 are used.
7 and the voice communication I / F unit 18 are arranged on the same data bus 30. For this reason, when data communication occurs between the digital signal processing processor 17 and the voice communication I / F unit 18, the data bus 30 is occupied by this communication, so that the MAP message is immediately transferred to the CPU 5. You may not be able to. Therefore, C
The analysis of the MAP message may be delayed depending on the processing performance of the PU 5 and the use status of the data bus 30. Therefore, at a given time, the cable modem device
There is a risk that the pstream data cannot be transferred, and there is a problem that the communication performance of the cable modem device is reduced. Further, there is a problem that the cable modem device itself does not operate. In this case, the high speed and wide bandwidth of the CATV network cannot be fully utilized, and a data communication service cannot be provided to the subscriber.

On the other hand, it is necessary to guarantee the real-time property that the processing of audio data is completed within a certain delay time. For this reason, priority is given to processing relating to basic operations of the cable modem device, such as analysis of a MAP message, and if processing relating to voice communication is delayed beyond an allowable level, sound skipping (increase in silence) will occur, resulting in poor sound quality. There is a problem of deterioration. In this case, it is impossible to provide a subscriber with a voice quality communication service that can be used.

[0010] Further, communication protocols using the Internet and CATV networks change daily, and the capability required for the protocol processing is increasing. For this reason, there is a problem that the cable modem device will soon become obsolete unless the cable modem device can meet the required performance in the future.
Therefore, it cannot be guaranteed that the data communication service can be provided to the subscriber in the future.

An object of the present invention is to securely process information related to the setting and operation of a cable modem device, and to provide a subscriber with a voice communication service using VoIP technology required on the Internet in the future. It is an object of the present invention to provide a semiconductor device and a cable modem device for controlling a cable modem that can be put on the market at an early stage at a high performance and at a low price, which can cope with an increase in processing capacity due to a change in a protocol in the future.

[0012]

According to the present invention, an external CPU is provided.
A first interface unit connected to a memory and a memory, a second interface unit connected to an external computer,
A third interface unit connected to an external telephone, and connected to the first interface unit and the second interface unit to transmit and receive MAC frames to and from the first interface unit and the second interface unit MAC to do
A cable having a transmission / reception unit and an audio signal processor connected to the first interface unit and the third interface unit and transmitting / receiving audio information to / from the first interface unit and the third interface unit A semiconductor device for controlling a modem is characterized. Further, the present invention is characterized by a cable modem device using the semiconductor device. Also, a method for controlling such a cable modem device is characterized.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a cable modem device according to an embodiment of the present invention. As shown, the cable modem device 1 includes a filter unit 3, a tuner unit 4, a CPU 5,
, RAM 6, ROM 7, and cable modem controller LSI9.
The cable modem controller LSI 9 is mutually connected by an external bus 8. Further, the cable modem controller LSI 9 performs A / D conversion and QAM 16 /
A demodulation unit 10 for performing QAM256 demodulation processing, MPEG frame synchronization processing, Reed-Solomon code error correction processing, and the like;
A modulation unit 11 for performing Reed-Solomon encoding, QPSK / QAM16 modulation, D / A conversion, etc., and a MAC (Me
dia Access Control) Layer 12
A frame storage unit 13, an external bus I / F unit 14,
Digital signal processing processor 17 and voice communication I
/ F section 18 and a PC connection I / F section 19, which are physically realized by one LSI. The components of the cable modem controller LSI 9 described above are interconnected by the internal bus 15 and the internal bus 16, so that necessary control commands and data can be transmitted. Hereinafter, the function, basic operation, and data flow of each unit of the cable modem device 1 will be described in detail.

The CPU 5 is mainly composed of a microprocessor, and executes processing according to a software program stored in the RAM 6 or the ROM 7. For example, by installing a real-time OS (operating system) in the ROM 7, the cable modem device 1
Hardware and a plurality of tasks can be efficiently processed, and a wide range of control can be performed from basic transmission / reception operations to processing of various interfaces. The CPU 5 provided in the cable modem device 1 according to the embodiment of the present invention includes, for example, the head end modem device 2
MAC such as MAP message periodically transmitted from
It performs frame processing and protocol processing of each network layer such as TCP / IP related to voice communication, and is mainly in charge of setting and basic control of the cable modem device 1. The RAM 6 and the ROM 7 function as a work area of the CPU 5, and are used as a memory for temporarily storing a software program or an OS that defines an operation procedure of the CPU 5, a command and data processed by the CPU 5, and the like. The filter unit 3 includes a CATV network 23
To remove the high frequency noise of the Downstream signal transmitted through the cable 2 from the
It serves to prevent mutual interference between the signal and the Upstream signal.

First, the cable modem device 1 is set to Downst
When receiving the beam signal, the signal transmitted through the cable 2 enters the tuner unit 4 after passing through the filter unit 3, where a channel selection process is performed. Next, the selected analog signal enters the demodulation unit 10 of the cable modem controller LSI 9, and is converted from an analog signal to a digital signal by an A / D converter provided in the demodulation unit 10. Next, the data converted into a digital signal is subjected to demodulation processing by a method suitable for the environment and the like. The demodulation unit 10 of the cable modem controller LSI 9 according to the embodiment of the present invention supports the two demodulation systems of QAM16 and QAM256 as described above. The demodulated data is a transport stream which is a bit stream conforming to the MPEG2 standard, and a code error correction process for detecting and correcting data errors occurring in the CATV network 23 and the like for the data. And improve the reliability of the data. Through the above processing, the demodulation unit 10 of the cable modem controller LSI 9 outputs a MAC frame in which the header part has been deleted from the transport stream on which the error correction has been finally performed.

Subsequently, the MAC frame output from the demodulation unit 10 enters the MAC layer unit 12. The MAC layer unit 12 refers to the destination address in the header portion of the input MAC frame and determines whether the frame data is addressed to the cable modem device 1 itself or is addressed to the subscriber's PC. Determine what it is. As a result, the data passes through the following two transfer paths. If the MAC frame is addressed to the cable modem device 1 itself, the MAC layer unit 12
The MAC frame is transferred to the CPU 5 or the RAM 6 via the / F unit 14. And the MAC frame is
It is processed by the CPU 5 and a software program. The data flow (A) at the time of Downstream in FIG. 4 collectively shows the data flow from the demodulation unit 10 to the storage in the RAM 6. If the MAC frame is addressed to the subscriber's PC, the MAC frame is transferred from the MAC layer unit 12 to the PC connection I / F unit 19 across the internal bus A15, and then sent to the subscriber's PC. Then, the MAC frame is processed by the PC. Downs of FIG.
The data flow (B) at the time of the stream is transmitted from the demodulation unit 10 to the P.
The data flow up to C is shown together.

The configuration of the external bus I / F section 14 provided in the cable modem controller LSI 9 according to the embodiment of the present invention has a switching function for connecting either the internal bus 15 or the internal bus 16 to the external bus 8. From the internal bus 15 to the internal bus 16.
Alternatively, data and commands cannot be directly transferred from the internal bus 16 to the internal bus 15.
The PC connection I / F 19 is 10BASE-T or 10BASE-T.
Ethernet and US represented by 0Base-T
B, a PCI bus I / F.

On the other hand, the cable modem device 1
When transmitting the eam signal, the signal passes through the following two transfer paths. First, the MAC sent from the subscriber's PC
The frame enters the PC connection I / F unit 19 of the cable modem controller LSI 9 of the cable modem device 1.
Thereafter, the data is temporarily transferred to the frame storage unit 13 connected to the MAC layer unit 12 via the internal bus 15 and the MAC layer unit 12. This frame storage unit 13
Is a memory for temporarily storing Upstream frame data, and is composed of a FIFO or an SRAM. The frame storage unit 13 may be configured to be provided outside the cable modem controller LSI 9 according to the provided memory capacity.

The CPU 5 is a cable modem device 1
Manages time slot information for transferring Upstream data to the cable 2. For this reason, MAC
The layer unit 12 determines in advance that the U
It notifies that the pstream data exists in the frame storage unit 13 and stores the data until the transmission permission from the CPU 5 is obtained. And the MAC layer unit 12
When the transmission time to Upstream is determined by the CPU 5, the CPU 5 reads the frame data stored in the frame storage unit 13 and outputs the frame data to the modulation unit 11. U in FIG.
The data flow at the time of pstream (C) summarizes the above data flow.

In some cases, the cable modem device 1 itself transmits data to the headend modem device 22 in the Upstream signal. In this case, first the CPU
5 prepares the Upstream data to be transferred in the RAM 6. Next, when the CPU 5 determines the transmission time to Upstream, the cable modem controller LSI
9 to the MAC layer unit 12 via the external bus I / F unit 14 and the internal bus 15 and output to the modulation unit 11. By the way, when transmitting Upstream data, the CPU 5 cannot accurately predict the time at which the right to use the bus can be acquired due to the use status of the internal bus 15. That is, the time at which data can be transferred from the RAM 6 to the MAC layer unit 12 becomes indefinite. Therefore, the Upstre assigned to the cable modem device 1
There is a possibility that data cannot be sent to the cable 2 so as to match the transfer time of am. Therefore, the Upstream data prepared in the RAM 6 by the CPU 5 is temporarily transferred to the frame storage unit 13 connected to the MAC layer unit 12 and stored therein, where the Upstream data is stored.
It is also possible to wait for the transmission time to be determined. Data flow at the time of Upstream in FIG. 4 (D)
The following summarizes the state of the above data flow.

Next, the Upstre input to the modulator 11
The am data is subjected to Reed-Solomon code processing in order to perform error correction on the side of the head end modem device 22, and then to modulation processing. The modulation unit 11 in the cable modem controller LSI 9 according to the embodiment of the present invention supports the two modulation schemes of QPSK and QAM 16 as described above. Further, a header portion is added to the modulated data, and a digital signal is converted into an analog signal by a D / A converter. By the processing described above, the modulation unit 11
Finally outputs an analog signal for Upstream to the filter unit 3 and propagates through the cable 2 to the CATV network 23.
Is transferred to the head-end modem device 22 via the.
The function, basic operation, and data flow of each unit of the cable modem device 1 have been described above.

Next, a description will be given of the functions, operations, and data flow of each unit when the cable modem device 1 according to the embodiment of the present invention handles voice information processing related to the VoIP technology.

First, the cable modem device 1 is connected to the Downst
When the beam signal is received, the demodulation unit 10 provided in the cable modem controller LSI 9 performs demodulation processing and the like, and then is input to the MAC layer unit 12. It is detected that the input MAC frame is addressed to the cable modem device 1. And At this time, such a MAC frame is transferred from the internal bus 15 to the CPU 5 or the RAM 6 via the external bus I / F unit 14. And CP
It is assumed that U5 and a software program further detect that the MAC frame contains voice data based on the VoIP technology. Then, the CPU 5 first performs preprocessing associated with calling / call disconnection, such as signaling for confirming the state of the other party of the call, starting / ending the call, and address conversion for converting a telephone number from an IP address to each other.
Performs protocol processing related to CP / IP. The above signaling method is described in H.264. 323 and the like. The audio data that has been subjected to the above-described signaling and network processing, etc., is immediately sent from the external bus I / F unit 14 of the cable modem controller LSI 9 via the internal bus 16 to the digital signal processing processor 1 for performing audio processing.
7 to release the CPU 5 and the external bus 8. The digital signal processing processor 17 performs processing related to the sound that the signal processing processor is good at, such as reproduction processing of compressed audio data, gain control, and echo cancellation. As a method of audio compression, G.A. 729a and G.G. 723.1. Further, the audio data processed by the digital signal processing processor 17 is transferred to the audio communication I / F unit 18 via the internal bus 16 again. Therefore, the digital PCM signal is converted into an analog signal, and is finally output to an IP Phone (telephone). The state of the above data flow is shown collectively in the data flow (E) at the time of Downstream in FIG.

On the other hand, when the cable modem device 1 outputs voice information to the cable 2 as an Upstream signal, first the voice communication I / O of the cable modem controller LSI 9 of the cable modem device 1 is transmitted from the IP Phone.
The signal enters the F section 18 where it is converted from an analog signal to a digital PCM signal. Next, the converted PCM signal is transferred to the digital signal processing processor 17 via the internal bus 16, and performs processing such as voice compression and data packetization. The data after the voice processing is transferred from the digital signal processing processor 17 to the CPU 5 or the RAM 6 via the external bus I / F unit 14, and the CPU 5 and a software program execute signaling, address conversion, and protocol processing relating to TCP / IP. Is done. Upstream audio information stored in the RAM 6 is transmitted from the cable modem controller LSI to the RAM 6 according to time slot information managed by the CPU 5.
The data is transferred to the MAC layer unit 12 via the external bus I / F unit 14 and the internal bus A15, and sent out to the cable 2 as Upstream data. Or RAM6
Is stored in the MAC layer 1 of the cable modem controller LSI9.
The data may be temporarily stored in the frame storage unit 13 connected to the cable 2 and then transmitted to the cable 2. Upstream in FIG.
The data flow at the time (F) summarizes the above data flow.

As described above, the processing of the MAC frame related to the setting and operation of the cable modem device 1 is performed by the CPU 5, and the processing is divided into signaling and network processing with a small processor load related to the VoIP technology and voice processing with a large processor load. Internal bus 1 provided inside CPU 5 and cable modem controller LSI 9
6 is performed by the processor 17 for digital signal processing. For this reason, the CPU 5 can minimize the consumption of resources associated with the voice processing by the VoIP technology, and can allocate the processor capability to the information processing related to the basic operation of the cable modem device 1. Further, by performing the voice information processing by the digital signal processing processor 17, necessary processor capability can be ensured.

Further, a cable modem controller LSI
9, by providing two independent internal buses, an internal bus 15 and an internal bus 16,
2 and the communication between the CPU 5 and the RAM 6 and the communication between the digital signal processing processor 17 and the voice communication I / F 18 can be prevented from conflicting with each other. For example, it is assumed that the MAC layer unit 12, the digital signal processing processor 17, and the voice communication I / F unit 18 exist on the internal bus 15.
This consists of a CPU 5 and a processor 17 for digital signal processing.
Apparently exist on the same bus. When the MAC layer unit 12 acquires the right to use the internal bus 15 and performs data transfer with the CPU 5 and the RAM 6, the digital signal processing processor 17 and the voice communication I / F unit 18 Cannot be obtained, so that data cannot be transferred between the digital signal processing processor 17 and the voice communication I / F unit 18. On the other hand, the digital signal processor 17 obtains the right to use the internal bus 15 and uses the voice communication I / F.
When data transfer is performed between the MAC layer unit 12 and the CPU 5, the MAC layer unit 12 and the CPU 5 cannot acquire the right to use the bus.
6 cannot transfer data. Therefore CP
Despite the provision of the digital signal processing processor 17 separately from U5, the data transfer efficiency is reduced due to the use state of the internal bus, and the capability of the processor cannot be fully utilized. However, according to the cable modem controller LSI 9 of the embodiment of the present invention, the above-mentioned problem can be solved, and a one-chip cable modem controller LSI for a cable modem device optimized for voice communication by VoIP technology can be provided.

On the other hand, by providing the CPU 5 on the external bus 8 separately from the cable modem controller LSI 9, the overall performance of the cable modem device can be improved in accordance with the progress of the processing performance of the processor. Does not become obsolete.

[0029]

As described above, according to the present invention, it is possible to reliably process information relating to the setting and operation of the cable modem device, and to simultaneously provide a voice communication service using the VoIP technology. In addition to the cable modem function, the LSI has been integrated into a single chip including a voice processing function.
, It is possible to construct a cable modem device which can be put on the market at an early stage with high performance / low cost.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a cable modem device according to an embodiment.

FIG. 2 is a diagram showing a configuration of an Internet system using a CATV network.

FIG. 3 is a diagram showing a configuration of a conventional cable modem device.

FIG. 4 is a diagram illustrating a data flow of a basic MAC frame according to the embodiment;

FIG. 5 is a diagram illustrating a data flow of a MAC frame related to audio information processing according to the embodiment.

[Explanation of symbols]

1 ... Cable modem device, 5 ... CPU, 6 ...
RAM, 8 external bus, 9 cable modem controller LSI, 12 MAC layer, 14
... External bus I / F section, 15 ... Internal bus, 16
..Internal bus, 17 ... Processor for digital signal processing, 18 ... I / F section for voice communication, 19 ... PC
I / F for connection.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor: Hashito Ishihara 5-2-1, Josuihonmachi, Kodaira-shi, Tokyo F-term in Hitachi Semiconductor Group 5C064 BA01 BB05 BB10 BC20 5K034 AA10 CC05 CC06 FF05 GG03

Claims (6)

[Claims] A first interface unit connected to an external CPU and a memory; a second interface unit connected to an external computer; and a third interface connected to an external telephone.
A MAC transmitting / receiving unit connected to the first interface unit and the second interface unit for transmitting / receiving a MAC frame to / from the first interface unit and the second interface unit; Cable modem connected to the first interface unit and the third interface unit for transmitting / receiving audio information to / from the first interface unit and the third interface unit. Semiconductor device that controls 2. The semiconductor device according to claim 1, further comprising: a demodulation unit connected to the MAC transmission / reception unit for demodulating downstream data; and a modulation unit connected to the MAC transmission / reception unit for modulating upstream data. The semiconductor device according to claim 1, wherein: 3. A cable modem device having a CPU, a memory, and a control semiconductor device, wherein the control semiconductor device has a first interface unit connected to the CPU and memory, and a second interface unit connected to an external computer. 2 interface unit, a third interface unit connected to an external telephone, and a first interface unit and a second interface unit connected to the first interface unit and between the first interface unit and the second interface unit. A MAC transmitting / receiving unit that transmits / receives a MAC frame to / from a first interface unit and a third interface unit, and transmits / receives voice information to / from the first interface unit and the third interface unit. A cable modem device comprising an audio signal processor. 4. A first interface unit connected to a first internal bus and a second internal bus, a first interface unit connected to an external CPU and a memory, and connected to the first internal bus and a second internal bus. A second interface unit connected to the computer and connected to the first internal bus; and a third interface unit connected to an external telephone and connected to the second internal bus.
A MAC transmitting / receiving unit connected to the first internal bus and transmitting / receiving MAC frames to / from the first interface unit and the second interface unit via the first internal bus; A semiconductor device for controlling a cable modem, comprising: an audio signal processor connected to the internal bus 2 for transmitting and receiving audio information between the first interface unit and the third interface unit. . 5. A cable modem device having a CPU, a memory, and a control semiconductor device, wherein the control semiconductor device includes a first internal bus, a second internal bus, and the CP.
A first interface unit connected to the U and the memory and connected to the first internal bus and the second internal bus, a second interface unit connected to an external computer and connected to the first internal bus, A third interface unit connected to the external telephone and connected to the second internal bus; and a third interface unit connected to the first internal bus and connected to the first interface unit via the first internal bus and a second interface unit. MA for transmitting and receiving MAC frames to and from the interface unit
C. A cable, comprising: a transmission / reception unit; and an audio signal processor connected to the second internal bus and transmitting / receiving audio information to / from the first interface unit and to / from the third interface unit. Modem device. 6. A MAC transmission / reception unit provided in a cable modem for transmitting / receiving a MAC frame between an external head-end device and a subscriber computer, the MAC frame received from the head-end device being transmitted to the cable modem itself. If it is the first MAC frame for setting, operation and voice information, the CP in the cable modem
U transmitted to the U and received from the head-end device
The frame is a second MA associated with the subscriber computer.
If the frame is a C frame, it is transmitted to the subscriber computer. The MAC transmitting / receiving unit transmits a MAC frame received from the CPU and the subscriber computer to the head end device. The network processing of the MAC frame and the setting and operation of the cable modem itself are performed, the network processing of the MAC frame is performed on the voice information received from the voice signal processor, and the voice information is provided in the cable modem. The voice signal processor transmits the voice information sent from the CPU by the voice signal processor, and transmits the processed voice information to an external telephone. Processing of audio information received from And transmitting the processed voice information to the CPU.