JP2000183939A - Data transferring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain highly flexible data transfer between devices, and also clarify a data transferring procedure by adding a few circuits to a conventional hub device. SOLUTION: A data buffer 4 for storing data and a transaction controller 7 for controlling a repeater circuit 2, decoding a data transfer request received from a host computer through an upstream port 11, transmitting a token packet to the origin of data transmission, storing the received data in the data buffer 4, transmitting a confirmation packet to the origin of transmission, successively transmitting the token packet to the destination of reception and then the stored data, receiving the confirmation packet from the destination of reception, and transmitting the end status of data transfer to the host computer after confirming the acceptance of all data at the data transfer through a downstream port 20 are added to a conventional hub device. Also, a timing generating circuit 6 is provided for an isochronous data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a USB (Un
More particularly, the present invention relates to a data transfer device applied to a hub device used in an versatile serial bus), and in particular, by adding a small number of circuits to a conventional hub device, a highly flexible data transfer between devices can be achieved and data can be transferred. The present invention relates to a data transfer device in which a transfer procedure is clarified.

[0002]

2. Description of the Related Art First, referring to FIG. 5, a plurality of devices 5 are connected to a host computer (hereinafter abbreviated as a host) 30.
Hub devices 41 to 44 used for USB connecting 1 to 55 in a tree shape will be described.

In this example, the host 30 is connected to one hub device 41 as an upper device, and the hub device 41 connects hub devices 42 and 43 to lower devices. On the other hand, the hub device 42 has the hub device 41 as a host device and the devices 51 to 51.
53 is connected as a lower device. The other hub device 4
3 connects the hub device 41 as a higher-level device and the hub device 44 and the device 54 as lower-level devices.

That is, in this type of hub device, data transfer is performed between the host 30 and each of the devices 51 to 55. Therefore, the host side of the upper device side is upstream and the lower device side is down stream. On the stream side, it merely forms a data transfer path between the upper device and the lower device.

Next, referring to FIG. 6, one hub device 1 will be described.
00 will be described. Hub device 1
00 connects to a host via an upstream port 110 and connects to a device via a downstream port 120. The repeater circuit 131 accommodates the port controllers 111, 121, 122, to 12N of each port and the hub controller 132, and is controlled by the hub controller 132. Hub controller 13
The port controllers 121 and 122 of the downstream port 120 are connected to the communication path of the port controller 111 designated based on the data transfer request received from the host via the host upstream port 110.
Each of them is connected by controlling the repeater circuit 131.

As a result, for example, even when data is transferred from the device 51 connected to the hub device 42 shown in FIG. 5 to the device 52, the data transmitted from the device 51 is transmitted from the hub device 42 to the hub device 41. Relayed by the host 30 via the hub device 41 to the hub device 42 again.
Will arrive at the device 52. On the other hand, U
Since the data transfer capacity of the SB is limited, if this data is large, other data transmission is hindered.

A technique for solving this problem is described in, for example, Japanese Patent Application Laid-Open No. 10-107827.

As shown in FIG. 7, according to the data relay device 200, the line concentrator 231 is connected between the upstream port 210 and the downstream port 220.
An ABC transmission circuit 232, a transmission control circuit 233, and a connection switching device 234 are provided. Of these, ABC
A transmission circuit 232 and a transmission control circuit 233 are added to a conventional hub device as pseudo host means, and have the same functional operations as the host 30. Also, the connection switching device 23
4 connects the port controllers 221 and 222 in the downstream port 220 with each other.

[0009] The data relay device disclosed in this publication is described only as having the pseudo host function as described above, and the details thereof are not clear. In other words, the description from the data relay device to the lower device is described with a flowchart, but the transmission and reception of control packets with the host is not described. Also, the part of the pseudo host function corresponding to the host function is unclear.

[0010]

In the data relay device described in the above-mentioned publication as the above-mentioned conventional data transfer device, a pseudo data added to realize data transfer between devices without passing through a host. The interface between the host means and the host is unclear, and among the newly added parts, at least there is no description about information transfer on the side of the pseudo host means. There is a problem in terms of.

[0011] An object of the present invention is to solve the above-mentioned problems, and to add a small number of circuits to a conventional hub device, thereby enabling highly flexible data transfer between devices without the intervention of a host computer. It is another object of the present invention to provide a data transfer device in which a data transfer procedure is clarified.

[0012]

A data transfer device according to the present invention is applied to a hub device used for USB for connecting a plurality of devices to a host in a tree-like manner.
And a transfer unit for temporarily storing data received from the source device when receiving a data transfer request from the host to the device, and transmitting the data to the destination device;
The time when the temporarily stored data is transmitted from the transmission source device can be transmitted after confirming the normality of the received data.

As described above, by temporarily storing transfer data between devices, the data transfer device according to the present invention can transfer data between lower devices without being limited to the same channel or the same time slot. Enables flexible data transfer between devices.

[0014] Further, with regard to the transmission and reception of specific messages between the host and the device, the data transfer device uses the transfer means to transmit a data transfer request from the host to devices included in its own lower device. Upon receiving the data, a token packet for data reception is sent to the data transmission source device to receive the data, then the normality of the received data is confirmed and temporarily stored, and the data reception confirmation packet is transmitted to the data transmission source. The data transmission packet is transmitted to the data receiving device, and the stored data is transmitted to the receiving device to receive a data reception confirmation packet from the receiving device. Check that all data has been received from the host.After that, when the host requests the status, the data is transferred. It is sending the termination of status.

Further, a specific configuration of the data transfer device according to the present invention includes a repeater circuit for accommodating one high-order device and a plurality of low-order devices, and one high-order device for controlling and connecting this repeater circuit and a plurality of low-order devices. A hub controller that controls the basic functions of a hub that connects to and relays data to lower-level devices; a data buffer that stores data to be input by connecting to devices and circuits accommodated in a repeater circuit; When receiving a data transfer request between devices included in the apparatus, the controller controls the repeater circuit to receive data from the requested data transmission source device, temporarily stores the received data in a data buffer, and then executes the repeater circuit. And a transaction controller for sending the data to the data receiving device via the communication controller.

Further, when the transaction controller receives a data transfer request from a host computer to devices included in lower-level devices, the transaction controller first sends a token packet for data reception to a data transmission source device via a repeater circuit. The data is received, the normality of the received data is confirmed, the data is temporarily stored in the data buffer, and a data reception confirmation packet is transmitted to the data transmission source. On the other hand, the transaction controller sends a packet for sending data to the data receiving device via the repeater circuit, and then controls the data buffer and sends the stored data to the receiving device via the data buffer. After receiving the data reception confirmation packet from the destination device and then confirming that all data has been received from the transmission source device, when the status is requested from the host, send the data transfer completion status. ing.

As an additional function, it is possible to provide a timing generation circuit which is controlled by the transaction controller, measures a time limit for data transfer subject to time restrictions including transfer timing, and notifies the transaction controller.

With such a configuration, it is only necessary to add a minimum necessary circuit to the case where data is transferred between devices without the intervention of a host computer.
Further, the data transfer procedure between the host and the device in the data transfer apparatus according to the present invention is clarified.

[0019]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram showing an embodiment of the present invention. The data transfer device 1 shown in FIG.
This is one of the basic modes. The upstream port 10 and its port controller 11 for connecting a higher-level device, the downstream port 20 and its port controllers 21 and 22N for connecting a lower-level device, the repeater circuit 2, the hub controller 3, The data buffer 4 and the transaction controller 5 are assumed. The host is the highest-level device, and the higher-level devices other than the host include a hub device and the data transfer device according to the present invention. The lower-level device includes a device and a data transfer device according to the present invention.

The repeater circuit 2 includes a port controller 1
1, 2, 22, and 2N, the hub controller 3, the data buffer 4, and the transaction controller 5 are accommodated and connected, and an instruction is received from each controller to connect these circuits to form a communication path. Hub controller 3
Has a function similar to that of a conventional hub device, and controls the repeater circuit 2 when a token packet for a data transmission source or a data reception destination is received from a higher-level device via the port controller 11 and the repeater circuit 2. A communication path for this data transfer is formed.

The data buffer 4 receives data from a source device via a communication path formed in the repeater circuit 2 and one of the downstream ports 20 under the control of the transaction controller 5 when transferring data between devices. Is received and stored, and the stored data is stored in the transaction controller 5.
And transmits the data to the receiving device via the communication path formed in the repeater circuit 2 and one port controller of the downstream port 20.

The transaction controller 5 includes a port controller 11 and a repeater circuit 2
, When a data transfer request is input, a conventional USB transaction is generated to cause data transfer. Specifically, the transaction controller 5
Recognizes from the received data transfer request that the source device and the destination device of the data are included in its own lower device, and controls the repeater circuit 2 and the data buffer 4 to communicate between the port controllers of the downstream ports 20. Performs data transfer. See Figure 3 for details of this function.
This will be described later with reference to FIG.

Next, with reference to FIG. 2, an embodiment of the configuration when the data transfer device 1 shown in FIG. 1 is used on a USB will be described. 2, the data transfer device 1 shown in FIG. 1 is used instead of the hub device 42 shown in FIG. The reference numerals shown in FIG. 2 are the same as those shown in FIG. 1, and the components having the same names are shown.

The illustrated data transfer device 1 is connected to a hub device 41 as a host device, and can interface with the host 30 via the hub device 41. On the other hand, as the lower-level device, devices 51, 52, and 5 are assigned to the port controllers 21, 22, and 23 of the downstream port 20, respectively.
3 are connected.

Next, this function will be described with reference to FIGS. 1 and 2 in addition to the operation procedure of FIG.

First, when the data transfer device 1 receives a data transfer request from the host 30 via the hub device 41 at the port controller 11 (YES in step S 1), the port controller 11 controls the repeater circuit 2. The received transfer request is sent to the transaction controller 5.
The transaction controller 5 decodes the received transfer request and, when recognizing that the data transfer is from the device 51, which is its own lower device, to the device 52 (procedure S2), controls the repeater circuit 2 to control the port controller 2
A token packet for receiving data, called an in-token packet, is transmitted to the device 51, which is the data transmission source, via the device 1 (step S3).

As a result, the transaction controller 5 accepts data input from the data transmission source device 51 (step S4), so confirms that the received data is normal (step S5: YES), Is stored in the data buffer 4 (procedure S6). Usually US
In B, the end of the packet (reception completed) is indicated by EOP
(End of Packet) signaling, that is, a method in which two data signal lines on the USB are simultaneously set to a low level, can be notified to the receiving side. Next, the transaction controller 5 sends, via the port controller 21, an acknowledgment packet (so-called ACK packet) that replies that the data has been normally received to the device 51 that has transmitted the data (step S7).

Subsequent to the procedure 7, the transaction controller 5 controls the repeater circuit 2 to transmit the data to the device 5 via the port controller 22.
After transmitting a token packet for data transmission called an out-token packet to the device 2 (step S8), the repeater circuit 2 is controlled to transmit the data buffer 4 from the data buffer 4 to the device 52, which is the data receiving destination, via the port controller 22. Is transmitted (step S9).

Next, the transaction controller 5
Receives an acknowledgment (ACK) packet indicating that the transmitted data has been received from the data receiving device 52 via the port controller 22 (step S10).
YES), the number of bytes received so far is measured (step S11), and the coincidence with the number of bytes which is the data amount notified as the first data from the transmission source device 51 is checked (step S12).

On the other hand, the host 30 sends a status request for the data transfer request sent earlier via the hub device 41, and the port controller 11 receives the request via the hub device 41 in the data transfer device 1.

If the data amount matches in step S12, the transaction controller 5 can receive a status request from the port controller 11 (YES in step S13). Is transmitted from the port controller 11 to the host 30 via the hub device 41 (procedure S14), and the procedure ends.

If the data received from the transmission source device 51 contains an error or if the data is not received within a predetermined time in the above-mentioned procedure S4, Further, the above procedure 12
Is "NO", and the received data amount is less than the notified amount, the receiving packet is transmitted to the data transmission source device 51, and the process returns to the above step S3 to wait for the arrival of data.

If the above step S10 is "NO" and the data reception confirmation packet is not received from the receiving device 52 within the predetermined time limit, the receiving device 5
Step S8 for sending a token packet to be sent to S2
And the data stored in the data buffer 4 is retransmitted.

In the above description, only the device is connected to the lower device of the data transfer device. However, the data transfer device according to the present invention, as applied to the hub device 43 in FIG. Or, when a data transfer device is connected and the device connected to these lower devices and the device that is its own lower device, or the device connected to each different lower device, transfer data between them, By decoding the transfer request, the above-described function can be exhibited. Incidentally, a data transfer request between a device and a lower device whose decoding result is connected to one lower device is relayed and transferred to the corresponding lower device. Also,
When one of the lower-level devices is a transmission source or a reception destination, a packet for data reception or data transmission is transferred instead of a data transfer request.

Next, another embodiment different from the data transfer apparatus 1 described above with reference to FIG. 4 and FIG. 1 will be described.

The data transfer device 9 shown in FIG. 4 further includes a timing generation circuit 6 as a component, and a transaction controller 7 connected to the timing generation circuit 6 and having a modified function. Have been.

The timing generation circuit 6 mainly corresponds to isochronous data including call voice data or moving image data which need to be transferred in real time. That is, for example, the timing generation circuit 6
At a timing based on the measurement of ms, a transaction generation signal is given to the transaction controller 7,
The transaction controller 7 receiving this transaction generation signal performs data transfer between the devices only once.

Therefore, the host computer cannot transfer data between an input device such as a video camera or a microphone that transmits continuous data at a predetermined cycle and an output device such as an image display device or a speaker connected thereto. , Data transfer between devices can be made possible.

In the above description, for example, it has been described that the data from the transmission source device is sent to the transaction controller via the repeater circuit, and the transaction controller stores the data in the data buffer. After the data is stored in the data buffer via the communication controller, the transaction controller may confirm the normality. As described above with reference to the drawings, the configuration change of the functional block by the separation and merging of the functions in the above description, or the change of the procedure by the replacement before and after the operation, the parallel processing, and the like, as long as the above functions are satisfied It is free and the above description does not limit the present invention.

[0041]

As described above, according to the data transfer apparatus of the present invention, when data is transferred between devices in USB, the flexibility between devices is reduced by adding a small number of circuits to a conventional hub device. And the data transfer procedure can be clarified.

The reason is that, when the data transfer apparatus performs data transfer between devices without the intervention of a host computer, a data buffer for temporarily storing data transferred between the devices and a transaction for generating a data transfer procedure are provided. This is because only a controller and a circuit necessary for data transfer between devices are additionally provided in the conventional hub device. Also, the data transfer procedure between the host and the device in the data transfer device is clarified.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

FIG. 2 is a device connection diagram showing one embodiment of a USB to which the device shown in FIG. 1 is applied.

FIG. 3 is a flowchart showing an embodiment of a main operation procedure in the apparatus shown in FIG.

FIG. 4 is a functional block diagram showing another embodiment different from the device shown in FIG. 1;

FIG. 5 is a device connection diagram showing one mode of USB.

FIG. 6 is a functional block diagram showing an example of a conventional device.

FIG. 7 is a functional block diagram showing another example different from the device shown in FIG. 6;

[Explanation of symbols]

 1, 9 Data transfer device 2 Repeater circuit 3 Hub controller 4 Data buffer 5, 7 Transaction controller 6 Timing generation circuit 10 Upstream port 11, 21, 22, 2N port controller 20 Downstream port 30 Host (host computer) 41, 42 , 43, 44 Hub device 51, 52, 53, 54, 55 Device

Claims (6)

[Claims] 1. A USB (Universal Se) for connecting a plurality of devices to a host computer in a tree-like manner.
In a data transfer device applied to a hub device used for a real bus, when a data transfer request between the devices is received from a host computer, the data received from a transmission source device is temporarily stored, and then temporarily stored in a reception destination device. A data transfer device having transfer means for sending. 2. The data transfer device according to claim 1, wherein the timing of transmitting the temporarily stored data from the transmission source device is after confirming the normality of the received data. 3. A data transfer device applied to a hub device used for USB which connects a plurality of devices to a host computer in a tree-like manner. In the data transfer device, a request to transfer data from the host computer to the devices included in its own lower device. When receiving the data, it sends a token packet for data reception to the data transmission source device to receive the data, then confirms the normality of the received data, temporarily stores the data, and sends a data reception confirmation packet to the data transmission source. And sends a packet for data transmission to the data receiving device, and then sends the stored data to the receiving device to receive a data acknowledgment packet from the receiving device. When the status is requested from the host computer after confirming the transfer of all data received from the device Data transfer device for transmitting a data transfer completion status to the data transfer device. 4. A data transfer device applied to a hub device used for USB which connects a plurality of devices to a host computer in a tree-like manner, and a repeater circuit accommodating one upper device and a plurality of lower devices. A hub controller for performing a basic function of hub control for connecting and relaying data between one higher-level device and a plurality of lower-level devices for controlling and connecting a repeater circuit, and connecting to a device and a circuit accommodated in the repeater circuit And a data buffer for storing data to be input, and when receiving a data transfer request between devices included in the lower-level device from a host computer, controlling the repeater circuit to request a data transmission source device. After receiving data and temporarily storing the received data in the data buffer, via the repeater circuit A data transfer device, comprising: a transaction controller that sends the data to a data receiving device. 5. The data transfer device according to claim 4, wherein the transaction controller first receives a data transfer request between devices included in the lower-level device from the host computer via the repeater circuit. A token packet for data reception is transmitted to receive data, the normality of the received data is confirmed, the data is temporarily stored in the data buffer, and a data reception confirmation packet is transmitted to the data transmission source, while the packet is transmitted through the repeater circuit. Sends a packet for data transmission to the data receiving device, and then controls the data buffer to send the stored data to the receiving device via the data buffer. Packet and then all data from the source device. A data transfer completion status is transmitted when a status is requested from the host computer. 6. The timing generating circuit according to claim 5, further comprising: a timing generation circuit that is controlled by the transaction controller, measures a time limit for a data transfer that is subject to a time constraint including a transfer time, and notifies the transaction controller. A data transfer device characterized by the above-mentioned.