JPH01243639A - Modem device - Google Patents

Abstract

PURPOSE:To reduce burden on hardware and software by providing an HDLC framing part and an HDLC deframing part in a MODEM and executing HDLC framing and deframing on the side of the MODEM. CONSTITUTION:Functions for executing high level data link control(HDLC) framing and deframing are given to the internal part of a control DSP 13 which executes the digital signal processing of the MODEM 11. A MODEM controller 10 gives a control signal, makes the MODEM 11 in a reception state and transmits data to the MODEM 11. In the MODEM 11, received data is HDLC- framed in an HDLC framing part 17 and is modulated so as to be transmitted on a line 14. At the time of data reception on the other hand, the MODEM 11 demodulates received data, executes HDLC deframing and transmits data to the MODEM controller 10. Thus, the MODEM controller 10 can execute only MODEM control, and burden on hardware and software is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a modem device, and more particularly to a modem device that can efficiently perform HDLC processing of transmitted and received data.

BACKGROUND OF THE INVENTION In recent years, in communication systems such as facsimiles, a method has been developed to convert communication data into HDLC (High Level Data Link Φ Control) format in order to detect communication data errors caused by line quality, etc. A lot is taken. In order to perform HDLC framing or deframing, an HDLC framing/deframing processing section has conventionally been provided in a modem control device. A conventional example of such a modem device is shown in FIG. This modem device is connected to a modem control circuit 1 and this modem control circuit 1, and is connected to an HDLC for transmission data.
a modem control device 3 having an HDLC circuit 2 that performs framing and HDLC deframing on received data; and a modem control device 3 disposed between the modem control device 3 and a line 4;
A modem 8 having an I10 circuit 5 for inputting and outputting data, a control digital signal processor 6 composed of a CPU for controlling digital signals, and an analog circuit 7 for performing analog communication between the line 4. Become.

The modem control device 3 connects the modem 2 with control lines IA, IB, and data line 2A.

Data is exchanged and control signals are exchanged through 2B. Further, within the modem control device 3, the control circuit 1 and the HDLC circuit 2 are connected to each other by signal lines 3A and 3B to exchange data.

For example, when transmitting data, the control circuit 1 in the modem control device 3
puts the modem 8 into the receiving state using control lines IA and IB. Next, the control circuit 1 has a signal line 3A.

3B, HDLC circuit 1 circuit 2 inside modem control device 1
control and write the transmission data. Data subjected to HDLC framing by the HDLC circuit 2 is sent to the modem 8 through the signal line 2A. Modem 8 modulates the data and sends it out on line 4. Also, during reception, the signal input from the line 4 is demodulated by the modem 8, and the demodulated data is sent to the H within the modem control device 3 through the signal line 2B.
The signal is input to the DLC circuit 2. The control circuit 1 then receives the deframed data via the signal line 3B.

Problems to be Solved by the Invention However, in the conventional modem device as described above, since the HDLC circuit 2 is incorporated in the modem control device 3, this modem control device 3 does not play the original role. In addition to controlling a certain modem 8, the HDLC circuit 2 had to be controlled, which placed a heavy burden on the hardware and software.

Means for Solving the Problems In order to solve the above problems, the present invention provides a modem control DSP.
The gist is that a function for performing HDLC framing and deframing is provided internally, so that HDLC framing and deframing can be performed on the modem side.

The operating modem controller issues control signals to place the modem in a receive state and send data to the modem. In the modem, received data is subjected to HDLC framing in a framing section of an HDLC circuit, and the data is modulated and sent onto the line. On the other hand, when receiving data, the modem demodulates the received data, then performs HDLC deframing and sends it to the modem control device. As a result, the modem control device only needs to control the modem, which reduces the burden on hardware or software.

Embodiment FIG. 1 is a block diagram showing an embodiment of a modem device according to the present invention. The modem device according to this embodiment includes a modem control device 10 having a control circuit 9, and a modem 11 controlled by the modem control device 10 to modulate and demodulate transmitted and received data.

The modem 11 includes an I10 circuit 12 that interfaces with a modem control device, a control DSP 13 that performs digital signal processing, and an analog circuit 15 that is connected to a line 14. Furthermore, the control D S P 13 is I1
0 circuit 12 through a signal line 16, a memory 18 that stores data after HDLC framing, a modulation section 19 that modulates transmission data, and a demodulation section that demodulates reception data. , a memory 21 for storing demodulated data, HDLC deframing is performed on the received data, and the I
10 circuits, and a control section 5 that is connected to each functional section via a bus and controls these functional sections. This control D S P 1
3, a bus is connected between the modulator 19 and the demodulator and the analog circuit 15 by a signal line r, and a branch signal line is connected from the signal line 16 to the memory bus. On the other hand, a branch signal line 31 extends from the memory bus (9) to the signal line n.

The operation of the modem device having such a configuration will be described below. The modem 11 is connected to the modem control device through the signal line 3.
2, it receives an HDLC mode designation command, a data transmission command, and transmission data. As a result, the modem 11 confirms that it is in the IDLC mode, and sends the transmission data to the HDLC framing unit 17 via the signal line 16.
input to perform HDLC framing. The HD'LC framed data is sent to the modulation section 19 via the memory 18, where it is modulated, then input to the analog circuit 15 through the signal line r, and output to the public line 14.

On the other hand, when receiving data, the modem 11 receives HDLC mode and reception mode commands from the modem control device 10 via the signal line 32, and enters the reception mode. The modem 11 then obtains a received signal from an analog circuit 15 connected to the public line 14 via a signal line. Control D
After the S P 13 demodulates the received signal in the demodulation section, the demodulated data is sent to the HDLC deframing section n.
DLC deframing is performed and the HDLC deframed data is sent to the I10 circuit 12 via the signal line n, and the I10 circuit 12 sends the received data to the modem control circuit 9 via the signal line 33.

As described above, data is transmitted after HDLC framing is performed in the modem 11.
Data is received while performing DLC deframing.

As described in detail, according to the present invention, an HDLC is installed in the modem.
Since a framing section and a deframing section are provided and HDLC framing and deframing are performed on the modem side, the burden on hardware and software on the modem control device is reduced, allowing efficient data transmission and reception. become.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a modem device according to the present invention, and FIG. 2 is a block diagram showing an example of a conventional modem device. 10...Modem control device, 11...Modem, 13.
...Control DSP, 14...Line, 17...HDLC
Framing section, 19...Modulation section, Addition...Demodulation section,
B...HDLC deframing section.

Claims (1)

[Claims] A modem control device having a modem control means, a means for performing HDLC framing processing on transmission data, a means for modulating the framed data, a means for demodulating the received data, and a means for demodulating the received data. A modem device comprising a modem and means for performing HDLC deframing processing.