JPH1188381A - Communication system, usb function device, communication system control method and medium recording communication condition display program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve convenience by displaying the transfer conditions of data in a communication system composed of a USB host device and a USB function device. SOLUTION: In a PID (packet identification field) detection circuit 32 on the side of this USB function device 20, whether it is the reception or transmission of the data is detected from a received token packet, the detection signals are respectively inputted to AND gates 41 and 42 and DMA request signals sent out from a function side USB transceiver 31 are inputted to the AND gates 41 and 42. Further, the display contents of a display device 70 are changed corresponding to the output of the AND gates 41 and 42. Thus, the transmission conditions and reception conditions of the data are displayed and the convenience is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a communication system for transferring data between a USB host device and a USB function device, the USB function device, a communication system control method for the communication system, and a communication status. The present invention relates to a medium on which a display program is recorded.

[0002]

2. Description of the Related Art Conventionally, U is capable of bidirectional data transfer.
A communication system including an SB host device and a USB function device does not include a display unit such as a display that indicates that data is being transferred.

On the other hand, in the communication system disclosed in Japanese Patent Application Laid-Open No. Hei 8-51447, the data output status of each electronic device is controlled in a communication system in which a plurality of electronic devices are connected by a P1394 serial bus to transfer data. It was indicated by LED.

[0004]

The conventional communication system described above has the following problems. In the former case, since there is no display means such as an indicator for indicating that data is being transferred, the data transfer status cannot be grasped.

On the other hand, in the latter case, P1394
Although it can be applied to a communication system including a plurality of electronic devices connected by a serial bus, it does not disclose any specific application example of a communication system using a USB.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been developed in a communication system including a USB host device and a USB function device, in which a data transfer status can be displayed to improve convenience. , A USB function device, a communication system control method, and a medium recording a communication status display program.

[0007]

According to a first aspect of the present invention, there is provided a USB host device having a predetermined transceiver and capable of transferring data,
The communication system includes an SB function device and includes a data transfer status display unit that displays a data transfer status between the USB host device and the USB function device. That is, a USB host device having a predetermined transceiver,
Data transfer with the USB function device is possible, and the data transfer status display means displays the data transfer status.

[0008] The data transfer status display means here,
Only the data transmission status may be displayed, or only the data reception status may be displayed, but it is preferable if both can be displayed. Therefore, according to a second aspect of the present invention, in the communication system according to the first aspect, the data transfer status display means is configured to individually display a data transmission status and a data reception status. That is, since the data transmission status and the reception status are individually displayed, it is easy for the user to understand.

According to a third aspect of the present invention, as an example of a specific configuration in a case where a data transmission state and a data reception state are individually displayed,
The USB host device sends a token indicating transmission or reception of data to the USB host device before data transmission / reception, and the USB function device receives a token indicating a predetermined D after receiving the token.
Based on the MA request signal, data is transmitted / received to / from the USB host device while DMA-transferring data between its own transceiver and the buffer memory, and the data transfer status display means includes the token and the DM
The transmission status and the reception status of the data are displayed based on the A request signal.

That is, the USB host device is:
Prior to data transmission / reception, a predetermined token is sent to the USB host device, and the USB function device receiving the token performs data transmission / reception while DMA-transferring data between its own transceiver and the buffer memory. . The data transfer status display means detects whether the data is transmitted or received from the token transmitted from the USB host device, and detects the data transfer time from the DMA request signal, Displays the data transmission status and reception status.

[0011] As another example of the configuration, the invention according to claim 4 is the communication system according to claim 2, wherein the USB host device transmits or receives data before transmitting / receiving data. The USB function device sends the token to the USB host device, and after receiving the token, the USB function device performs DMA transfer of data between its own transceiver and the buffer memory based on a predetermined DMA request signal while performing the DMA transfer. Send and receive data to and from
The data transfer status display means obtains the DMA count number at the time of the DMA transfer when the token is detected, and performs the data transmission or the data reception while counting the DMA count number based on a predetermined clock signal. Is displayed.

That is, data is transmitted and received between the USB host device and the USB function device in the same procedure as that described in the third aspect. The data transfer status display means detects whether data is transmitted or data is received from the token transmitted from the USB host device,
When the token is detected, the DMA count number at the time of DMA transfer between the transceiver on the USB function device side and the buffer memory is acquired. Thereafter, while the DMA count is counted based on a predetermined clock signal, a display indicating that data is being transmitted or received is displayed during data transmission or data reception.

In this case, it is easily understood that the display period during which data is being transmitted or data is being received depends on the frequency of the clock signal. Therefore, a fifth aspect of the present invention is the communication system according to the fourth aspect, wherein the data transfer status display means variably sets the frequency of the clock signal. That is, if the frequency of the clock signal is increased, the display period for displaying during data transmission or data reception is shortened, and if the frequency of the clock signal is decreased, the display period is extended.

The data transfer status display means can be installed at any location on the communication system configured as described above. For example, it can be installed as an independent device on the communication system. It can also be incorporated in a USB host device or USB function device. As an example of the latter case, the USB function device according to claim 6, including a predetermined transceiver, capable of transferring data to and from a USB host device, and transferring data to and from the USB host device Is displayed.

That is, the data transfer status display means is U
Because it is built into the SB function device,
The data transfer status is displayed on the USB function device side. As described above, in the communication system including the USB host device and the USB function device, even if the data transfer status is displayed, it is not necessary to be limited to a substantial device, and the method may function as a method. Easy to understand.

[0016] Therefore, an invention of a method according to claim 7 is a communication system control method for a communication system comprising a USB host device having a predetermined transceiver capable of transferring data and a USB function device. Then, the state of data transfer between the USB host device and the USB function device is detected and displayed on a predetermined display. In other words, there is no difference in that the present invention is not necessarily limited to a substantial device and is also effective as a method.

When the software for displaying the communication status is realized as an embodiment of the idea of the present invention, the software naturally exists on the recording medium on which the software is recorded, and may be used. As an example, the invention according to claim 8 is a medium in which a communication status display program for a communication system including a USB host device provided with a predetermined transceiver and capable of transferring data and a USB function device is recorded. Then, the state of data transfer between the USB host device and the USB function device is detected and displayed on a predetermined display.

Of course, the recording medium may be a magnetic recording medium, a magneto-optical recording medium, or any recording medium to be developed in the future. Also, the duplication stages of the primary duplicated product, the secondary duplicated product, and the like are equivalent without any question. In addition, the present invention is not limited to the case where the present invention is used even when the supply method is performed using a communication line, and the same applies to a case where the information is written on a semiconductor chip.

Further, even if a part is implemented by software and a part is implemented by hardware, there is no difference in the concept of the invention, and it is necessary to store a part on a recording medium. It may be in a form that is appropriately read in accordance with it.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 is a block diagram showing a communication system according to a first embodiment of the present invention.

In FIG. 1, a USB host device 10
Includes a host-side USB transceiver 11, and a USB function device 20 includes a function-side USB transceiver.
A host-side USB transceiver 11 and a function-side USB transceiver 31
Are connected by a D + signal line and a D- signal line.
B communication is enabled. This USB communication is performed according to the procedure shown in FIG.

That is, when the USB host device 10 receives data from the idle state, first, as shown in FIG. 3, the USB host device 10 issues an IN token for requesting the USB function device 20 to transfer data. Send. Upon receiving the IN token, the USB function device 20 transmits the USB data according to the request of the USB host device 10, and when the reception of the USB data is completed normally, the USB function device 20 transmits an ACK packet to the USB function device 20 to enter the idle state. Becomes

On the other hand, when the USB host device 10 transmits data from the idle state, as shown in FIG.
First, the USB host device 10 transmits an OUT token for requesting the USB function device 20 to prepare for data reception. Upon receiving the OUT token, the USB function device 20 receives the USB data in accordance with the request from the USB host device 10, and when the reception of the USB data is completed normally, the USB function device 20
An ACK packet is transmitted to the host device 10.

The packet format of the IN token and the OUT token is as shown in FIG.
From the beginning, a packet identification field (PID), an address field (ADDR), an endpoint field (ENDP), a CRC check field (CRC)
5). Packet identification field (PI
In D), information for identifying an IN token or an OUT token is set, and a specific function device on the USB interface is specified in the address field. In the end point field (ENDP), a specific end point in a specific function device is specified.
The C check field is a cyclic redundancy check code field for detecting a transmission error of the token packet.

The token packet thus configured is received by the function-side USB transceiver 31, and the PID detection circuit 32 reads information set in the packet identification field (PID), which is the first field of the token packet, and IN It identifies whether the token is a token or an OUT token. Further, two signal output lines are derived from the PID detection circuit 32 and connected to the AND gates 41 and 42, respectively. An OUT token detection signal is input to the AND gate 41, and the IN token is input to the AND gate 42. Input the detection signal. This OUT token detection signal becomes active when the PID detection circuit 32 detects an OUT token.
Is a signal that becomes active when an IN token is detected, and both become inactive when an ACK packet is transmitted and received.

As described above, when the token packet is received, transmission / reception of USB data is started. The USB function device 20 according to the present embodiment includes a buffer memory 50,
The B transceiver 31 improves performance by temporarily storing USB data to be transmitted and received in the buffer memory 50.

More specifically, when the USB function device 20 receives USB data, the function-side USB transceiver 31 sends a predetermined DMA request signal to the D-side.
The data is transmitted to the MA controller 61 and the DMA controller 6
1 receives the DMA request signal and transfers the received USB data to the buffer memory 50 by DMA. Meanwhile, USB
When transmitting USB data from the function device 20, after the USB data is once stored in the buffer memory 50, the function-side USB transceiver 31
A DMA request signal is transmitted to the MA
The A controller 61 receives the DMA request signal and transfers the USB data stored in the buffer memory 50 to the function-side USB transceiver 31.

Further, the DMA request signal is input to each of the AND gates 41 and 42 to an input terminal different from the input terminal connected to the signal output line. Therefore, the USB host device 10 sends the USB
When transmitting data to the function device 20, A
The ND gate 41 is gated each time a DMA request signal is transmitted. On the other hand, when data is transmitted from the USB function device 20 to the USB host device 10, similarly, the AND gate 42 is gated each time a DMA request signal is transmitted. Is done.

The outputs of the AND gates 41 and 42 are both input to the display 70. The display 70 includes two LEDs (not shown), one of which indicates that data is being transmitted to the USB host device 10 when lit, and the other LED indicates that data is being transmitted from the USB host device 10 when lit. Indicates that receiving is in progress. This indicator 70 is provided when there is a signal output from the AND gate 41.
The former LED is turned on, and when there is a signal output from the AND gate 42, the latter LED is turned on.

Accordingly, the user can visually check these two LEDs to confirm whether or not data has been transmitted / received. In the above sense, in the first embodiment, the PID
Detection circuit 32, AND gates 41 and 42, display 7
0 constitutes data transfer status display means.

Next, the operation of the first embodiment configured as described above will be described. USB host device 10
When transmitting data from the USB function device 20 to the USB function device 20, the USB host device 10 first transmits an OUT token for requesting the USB function device 20 to prepare for data reception. Then, this OUT token is received by the function-side USB transceiver 31, and the PID detection circuit 32 detects that it is an OUT token, and activates the OUT token detection signal.

After that, when the function-side USB transceiver 31 receives the actual USB data, the function-side USB transceiver 31 transmits a DMA request signal to the DMA controller 61. The received USB data is DMA-transferred to the buffer memory 50. Since the activated OUT token detection signal is input to one input terminal of the AND gate 41, when the DMA request signal is input to the other input terminal, the AND gate 41 is gated and displayed. The device 70 turns on the LED to indicate that data is being received from the USB host device 10.

If the USB function device 20 is a US
When the reception of the B data is completed, the USB host device 1
Then, an ACK packet is transmitted to 0 to notify that fact. Then, the PID detection circuit 32 deactivates the OUT token detection signal and enters an idle state, and the LED does not light up.

On the other hand, the USB function device 20
When transmitting data to the USB host device 10 from
First, the USB host device 10 transmits an IN token for requesting the USB function device 20 to transfer data. Then, this IN token is received by the function-side USB transceiver 31, and
The ID detection circuit 32 detects that it is an IN token and activates the IN token detection signal.

Thereafter, the USB function device 2
0 temporarily stores USB data to be transmitted to the buffer memory 50, and the function-side USB transceiver 31 transmits a DMA request signal to the DMA controller 61.
The DMA controller 61 that has received the request signal transfers the USB data stored in the buffer memory 50 to the function-side USB transceiver 31, and the function-side USB transceiver 31 transfers the USB data to the USB.
It is transmitted to the host device 10 side.

Since the activated IN token detection signal is input to one input terminal of the AND gate 42, when the DMA request signal is input to the other input terminal, the AND gate 42 is turned on. And display 7
0 indicates that the LED is turned on to transmit data to the USB host device 10. USB host device 1
When 0 completes the reception of the USB data, it transmits an ACK packet to the USB function device 20 to notify it. Then, the PID detection circuit 32 outputs I
The N token detection signal is deactivated to enter an idle state, and the LED does not light up.

<Second Embodiment> FIG. 6 is a block diagram showing a communication system according to a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals. It is attached. In the figure, the host-side USB transceiver 11 of the USB host device 10 and the U-side
Function side U of SB function device 21
The SB transceiver 31 is connected by a D + signal line and a D- signal line, and enables normal USB communication. In the USB communication in this case, similarly to the first embodiment described above, USB data is DMA-transferred between the function-side USB transceiver 31 and the buffer memory 50.

OUT output from the PID detection circuit 32
The token detection signal and the IN token detection signal are input to the host-side data transmission counter 43 and the host-side data reception counter 44, respectively. The host-side data transmission counter 43 and the host-side data reception counter 44
The DMA counter 6 operates when the OUT token detection signal and the IN token detection signal become active, respectively.
The DMA count is acquired from 2 and latched, and after the latch is completed, the DMA count is counted down by "1" and its output signal is activated until the count becomes "0".

The output signals of the host-side data transmission counter 43 and the host-side data reception counter 44 are input to a display 70, and the display 70 is active when the output signal from the host-side data transmission counter 43 is active. In some cases, while the LED indicating that data is being received from the USB host device 10 is turned on, the data is being transmitted to the USB host device 10 when the output signal from the host-side data reception counter 44 is active. Is turned on.

That is, in the second embodiment, while the output signal of the host-side data transmission counter 43 or the host-side data reception counter 44 is active, it is assumed that data transmission / reception is being performed. Therefore, although the display 70 does not display the data transmission / reception status in real time, the lighting time of the LED is relatively long and the visibility is improved. The above-described countdown in the host-side data transmission counter 43 and the host-side data reception counter 44 is performed in synchronization with a clock signal input from the clock generation circuit 81. The frequency of the clock signal output from the clock generation circuit 81 is variably set by the frequency setting unit 82.

That is, with such a configuration, the active period of the output signals of the host-side data transmission counter 43 and the host-side data reception counter 44 can be changed, and the convenience can be improved. . In the above sense, in the second embodiment,
PID detection circuit 32 and host-side data transmission counter 4
3, the host-side data reception counter 44, and the display 70
, The clock generation circuit 81 and the frequency setting unit 82 constitute data transfer status display means.

By the way, in the second embodiment, the state of data transmission / reception is displayed on the display 70 by combining several kinds of hardware, but the present invention is not limited to this configuration. For example, in the device shown in FIG. 7, the USB function device 21 includes a microcomputer 90, and the microcomputer 90 is provided with a program ROM.
By executing the communication status display program recorded in 91, the status of data transmission / reception is displayed on the display 70. Note that the microcomputer 90 operates with a clock signal transmitted from the clock generation circuit 81 as an input.

As a processing procedure of the microcomputer 90 for executing the communication status display program, first, when the function-side USB transceiver 31 receives a token packet, it detects the token packet and identifies an OUT token or an IN token. A DMA request signal is transmitted to 61. Then, the DMA controller 61 that has received the DMA request signal makes the function-side US
U between the B transceiver 31 and the buffer memory 50
The transfer of the SB data is started.

Thereafter, the microcomputer 90 sets the DMA counter 6
The DMA count is obtained from 2 and the countdown is started in the same manner as described above. While the countdown is being performed, a predetermined signal is transmitted so as to turn on the LED in the display 70 according to the type of the received token packet. Of course, the countdown speed can be controlled by software, and the speed may be set from an external input switch and may be read as appropriate.

Next, the operation of the second embodiment configured as described above will be described. USB host device 10
When transmitting data from the USB function device 21 to the USB function device 21, the USB host device 10 first transmits an OUT token for requesting the USB function device 21 to prepare for data reception. Then, this OUT token is received by the function-side USB transceiver 31, and the PID detection circuit 32 detects that it is an OUT token, and activates the OUT token detection signal.

Thereafter, when the function-side USB transceiver 31 receives the actual USB data, the function-side USB transceiver 31 transmits a DMA request signal to the DMA controller 61. The received USB data is DMA-transferred to the buffer memory 50.

The host-side data transmission counter 43 has an OU
When the T token detection signal becomes active, the DMA count number is obtained from the DMA counter 62 and latched. After the latch is completed, the DMA count number is counted down by "1" in synchronization with the clock signal input from the clock generation circuit. Then, the output signal is activated until the counted number becomes “0”. Then, the display 70 is LED
Is turned on to indicate that data is being received from the USB host device 10.

On the other hand, the USB function device 21
When transmitting data to the USB host device 10 from
First, the USB host device 10 transmits an IN token for requesting the USB function device 21 to transfer data. Then, this IN token is received by the function-side USB transceiver 31, and
The ID detection circuit 32 detects that it is an IN token and activates the IN token detection signal.

Thereafter, the USB function device 2
1 temporarily stores USB data to be transmitted to the buffer memory 50, and the function-side USB transceiver 31 transmits a DMA request signal to the DMA controller 61.
The DMA controller 61 that has received the request signal transfers the USB data stored in the buffer memory 50 to the function-side USB transceiver 31, and the function-side USB transceiver 31 transfers the USB data to the USB.
Transmit to the host device 10.

The host-side data reception counter 44 sets the IN
When the token detection signal becomes active, the DMA count is acquired from the DMA counter 62 and latched. After the latch is completed, the DMA count is counted down by "1" in synchronization with the clock signal input from the clock generation circuit. , Until the count number becomes "0". Then, the display 70 turns on the LED to indicate that data is being transmitted to the USB host device 10.

The countdown speed of the host-side data transmission counter 43 or the host-side data reception counter 44 depends on the frequency of the clock signal output from the clock generation circuit 81, and the frequency is variably set by the frequency setting unit 82. Therefore, the active period of the output signal from the host-side data transmission counter 43 or the host-side data reception counter 44 can be changed.

As described above, the PID detection circuit 32 on the side of the USB function device 20 detects whether data is received or transmitted from the received token packet, and sends the detection signal to the AND gates 41 and 42, respectively. The DMA request signal sent from the function-side USB transceiver 31 is input to AND gates 41 and 42, and the AND gate 4
Since the display contents of the display 70 are changed according to the outputs of the devices 1 and 42, the data transmission status and the data reception status can be displayed, and the convenience can be improved.

[0053]

As described above, according to the present invention, in a communication system including a USB host device and a USB function device, a data transfer status is displayed, so that a communication system capable of improving convenience can be provided. Can be provided. Further, according to the second aspect of the present invention, the data transmission status and the reception status are individually displayed, so that the data transfer status can be easily understood.

Further, according to the invention of claim 3,
The data transmission status and the reception status can be individually displayed with a simple configuration. Further, according to the invention of claim 4, it is possible to improve the visibility of the displayed contents while individually displaying the data transmission status and the data reception status with a simple configuration. Furthermore, according to the fifth aspect of the invention, the display period for displaying the data transmission status and the data reception status is made variable, so that a desired display mode can be selected.

Further, according to the invention of claim 6,
A USB function device capable of displaying a data transfer status can be provided. Further, according to the present invention, in a communication system including a USB host device and a USB function device, a data transfer status is displayed, so that a communication system control method capable of improving convenience can be provided. Can be provided.

Further, according to the invention of claim 8,
In a communication system including a USB host device and a USB function device, it is possible to provide a medium recording a communication status display program for displaying a data transfer status on a predetermined display.

[Brief description of the drawings]

FIG. 1 is a block diagram of a communication system according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of a transmission procedure at the time of data transmission and data reception of a USB host device.

FIG. 3 is a sequence diagram showing a transmission procedure when transmitting data from a USB function device to a USB host device.

FIG. 4 is a sequence diagram showing a transmission procedure when data is transmitted from the USB host device to a USB function device.

FIG. 5 is a schematic diagram showing a format of a token packet.

FIG. 6 is a block diagram of a communication system according to a second embodiment of the present invention.

FIG. 7 is a block diagram of a communication system according to a modification of the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... USB host device 11 ... Host side USB transceiver 20 ... USB function device 31 ... Function side USB transceiver 32 ... PID detection circuit 41, 42 ... AND gate 50 ... Buffer memory 61 ... DMA controller 70 ... Display

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 7/14 H04N 7/14

Claims (8)

[Claims] 1. A communication system comprising: a USB host device having a predetermined transceiver capable of transferring data; and a USB function device, wherein a data transfer status between the USB host device and the USB function device is displayed. A communication system, comprising: 2. The communication system according to claim 1, wherein said data transfer status display means individually displays a data transmission status and a data reception status. 3. The communication system according to claim 2, wherein the USB host device sends a token indicating data transmission or reception to the USB host device before transmitting / receiving data, and After receiving the token, the device transmits and receives data to and from the USB host device while DMA-transferring data between its own transceiver and the buffer memory based on a predetermined DMA request signal. A communication system, wherein the status display means displays data transmission status and reception status based on the token and the DMA request signal. 4. The communication system according to claim 2, wherein the USB host device sends a token indicating data transmission or reception to the USB host device before transmitting / receiving data, and the USB function After receiving the token, the device transmits and receives data to and from the USB host device while DMA-transferring data between its own transceiver and the buffer memory based on a predetermined DMA request signal. The status display means acquires the DMA count number at the time of the DMA transfer when the token is detected, and displays an indication during data transmission or data reception while counting the DMA count number based on a predetermined clock signal. A communication system, comprising: 5. The communication system according to claim 4, wherein said data transfer status display means variably sets a frequency of said clock signal. 6. A data transfer status display means which includes a predetermined transceiver and is capable of transferring data to and from a USB host device, and displays a data transfer status to and from the USB host device. A USB function device characterized by the above-mentioned. 7. A communication system control method for a communication system including a USB host device having a predetermined transceiver and capable of transferring data, and a USB function device, wherein the communication between the USB host device and the USB function device is performed. A method for controlling a communication system, comprising: detecting a data transfer status of the data and displaying the data on a predetermined display. 8. A medium in which a communication status display program for a communication system including a USB host device having a predetermined transceiver and capable of transferring data and a USB function device is recorded. A medium in which a communication status display program is recorded, wherein the status of data transfer between USB function devices is detected and displayed on a predetermined display.