JP2004287537A - Data transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure that an OS and a system can detect that a device is plugged into or unplugged from an IEEE1394 bus. <P>SOLUTION: A plug in/out detection means 104 in a plug in/out storage device 103 detects the plugging in/out of the device and stores it in a plug in/out storage means 105. Then a control device 101 reads from the plug in/out storage means 105, ensuring that it is possible to detect the plugging in/out of the device. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a data transfer device for performing data transfer between a plurality of devices connected on a bus having a hot-swap function.
[0002]
[Prior art]
In recent years, in view of the widespread use of digital technology in digital cameras and digital video, attempts have been made to connect such digital devices to the same bus and control them by a personal computer (hereinafter referred to as a PC). I have. Among such buses, the IEEE 1394 bus is capable of transmitting signals between arbitrary devices in any connection form, real-time data (isochronous data) such as AV signals, and non-transmission data such as device control commands. Real-time data (asynchronous data) can be transmitted at the same time, and it has become widespread as a serial bus excellent in compatibility with PCs and related devices.
[0003]
In addition, this serial bus allows hot swapping of digital equipment while the power of the equipment is turned on, but when hot swapping of a digital equipment is performed, the upper-level OS or system always detects the insertion and removal. I couldn't do it. There are several reasons for this, one of which will be explained. First, at the time of device insertion / removal, after a bus reset occurs on the serial bus, starting with the initialization of the topology, many packets are transmitted / received in order to initialize each device itself. These processes are performed by circuits in the interface card, and the results are transferred to the MPU as needed. MPU processing has a lot of unnecessary information and information including errors, and there are cases where the OS or system cannot cope. For these reasons, detection of device insertion / removal may be missed.
[0004]
Conventionally, as an invention for solving such a problem, a data transfer device described in Japanese Patent Application Laid-Open No. 2001-274803 is known. FIG. 4 shows the data transfer device. FIG. 4 shows a block diagram of a conventional data transfer device. 4, reference numeral 200 denotes an interface card, which includes a port circuit (PORT) 205, a physical layer circuit (PHY) 204, a link layer circuit (LINK) 203, a buffer memory (MEM) 202, an interface circuit (IF) 201, and an analysis circuit. The analysis unit 206 analyzes the packet based on the information of the port circuit 205 and the physical layer circuit 204 and inserts and removes the packet such as video data, control data, and information necessary for bus transfer. The information after the processing is completed is written into the buffer memory 202 and transferred from the interface circuit 201 to the MPU 207 via the internal bus.
[0005]
The operation of the conventional data transfer device configured as described above will be described below.
[0006]
First, a problem to be solved by the conventional example will be described. In IEEE 1394, which is a serial bus for realizing high-speed transfer, a PC is provided with an interface card having a specification specified by an OHCI (Open Host Controller Interface) protocol. The interface recognizes the state of the plug on the serial bus, sequentially accumulates packets (ID packets) in the internal buffer memory 202, and sequentially transfers the packets to the MPU 207 of the PC.
[0007]
The MPU 207 sets the transferred information in a device driver and an application program. From this information, confirm that the device has been inserted or removed.
[0008]
At this time, the data transfer device transfers the data or packet obtained from the bus even if there is an error. The received packet is stored in the buffer memory 202 and transferred to the MPU 207 as needed. In other words, the driver software and various application software are required to evaluate and analyze data obtained from these pieces of information, and to correctly deal with the results. However, it is difficult to assume everything, such as the content of an error, and the MPU 207 cannot perform processing correctly, and the system becomes unstable.
[0009]
In order to avoid these problems, the data received in the interface card 200 in the control device is accumulated in a time series and the data is analyzed, so that only the data after the sequence of the insertion / extraction process is increased, The MPU 207 can perform processing correctly.
[0010]
[Patent Document 1]
JP 2001-274803 A
[Problems to be solved by the invention]
In this data transfer device, hot-swapping can be supported by adding the function shown in the conventional example to the IEEE 1394 card. However, a conventional IEEE 1394 card or a PC having a function equivalent to the IEEE 1394 card in a chipset cannot be used. Therefore, an IEEE 1394 card to which a function shown in the conventional example is newly added, or a function corresponding to the IEEE 1394 card is added. It was necessary to prepare a personal computer. Further, it has been desired that a non-control-side device newly added to the IEEE 1394 bus be used.
[0012]
An object of the present invention is to reliably detect device insertion / removal / bus reset on an IEEE 1394 bus even when using a conventional IEEE 1394 card (OHCI card) or a PC having a function corresponding to the IEEE 1394 card in a chipset. And
[0013]
[Means for Solving the Problems]
In order to solve this problem, the invention according to claim 1 of the present invention comprises a control device for controlling another device on a bus having a hot-swap function, an insertion / removal detection means for detecting device insertion / removal on the bus, and A data transfer device to which an insertion / removal storage device having an insertion / removal storage unit for storing a result detected by the insertion / removal detection unit is connected, wherein when a device insertion / removal occurs on the bus, the insertion / removal detection unit includes the bus. By detecting the device insertion and removal on the above, the fact that the device has been inserted and removed is stored in the insertion and removal storage means, and the control device reads the presence or absence of device insertion and removal from the insertion and removal storage means of the insertion and removal detection device, It is configured to detect device insertion / removal on the bus.
[0014]
Accordingly, by newly providing a function to a newly developed device, an effect is obtained that device insertion / removal can be reliably detected even in a conventional device / device.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 of the present invention is a control device for controlling another device on a bus having a hot-swap function, a result of detection by the insertion / removal detection means for detecting device insertion / removal on the bus, and a result detected by the detection device. A data transfer device to which an insertion / removal storage device provided with an insertion / removal storage means for storing a device, wherein when device insertion / removal occurs on the bus, the insertion / removal detection means detects device insertion / removal on the bus. The control device detects the presence or absence of device insertion / removal by reading the presence / absence of device insertion / removal from the insertion / removal storage unit of the insertion / removal detection device. The data transfer device has an operation of reliably detecting device insertion / removal.
[0016]
The invention according to claim 2 of the present invention is characterized in that the insertion / removal detection means determines that a device is inserted / removed by a bus reset on the bus, and detects a change in state on the bus due to the occurrence of a bus reset. 2. The data transfer device according to claim 1, wherein the data transfer device has an effect of being able to do so.
[0017]
The invention according to claim 3 of the present invention is characterized in that the control device reads the presence / absence of device insertion / removal from the insertion / removal storage means of the insertion / removal detection device at regular time intervals. 3. The data transfer device according to claim 1, having an operation of enabling detection within a predetermined time.
[0018]
The invention described in claim 4 of the present invention is characterized in that the predetermined time interval is set to be longer than a time required for the bus reset state to converge, and to avoid an unstable state during the bus reset. 4. The data transfer device according to claim 3, which has an effect of enabling the data transfer.
[0019]
The invention according to claim 5 of the present invention is characterized in that the insertion / removal detection means stores a bus reset generated within a fixed time as one device insertion / removal, and a bus reset generated plural times during the bus reset. 5. The data transfer device according to claim 4, wherein said data transfer device has an effect of efficiently processing.
[0020]
The invention according to claim 6 of the present invention is characterized in that the predetermined time is set to be longer than a time required for the bus reset state to converge, and to avoid processing in an unstable state during the bus reset. 6. The data transfer device according to claim 5, which has an effect of being able to perform the data transfer.
[0021]
The invention according to claim 7 of the present invention is characterized in that the control device invalidates a device insertion / removal event detected in the control device when the insertion / removal storage device is present, 7. The data transfer device according to claim 6, wherein the data transfer device has an effect of enabling coexistence with an interrupt.
[0022]
The invention according to claim 8 of the present invention is the data transfer device according to claim 7, characterized in that the bus is an IEEE 1394 bus, and has an effect that the bus can be used on the IEEE 1394 bus.
[0023]
The invention according to claim 9 of the present invention is characterized in that the control device reads out the presence / absence of device insertion / removal from the insertion / removal storage means of the insertion / removal detection device by asynchronous transfer, and performs synchronous transfer by performing control by asynchronous transfer. 9. The data transfer device according to claim 8, which has an effect of not affecting.
[0024]
An invention according to claim 10 of the present invention is characterized in that the control device reads out the presence / absence of device insertion / removal from the insertion / removal storage unit of the insertion / removal detection device using an IEEE1394 standard AV / C command. 10. The data transfer device according to claim 9, which has an effect that a general configuration can be obtained by using a command.
[0025]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0026]
(Embodiment 1)
FIGS. 1 and 2 are a block diagram and a software / hardware configuration diagram for explaining a data transfer device according to the present invention. In FIG. 1, reference numeral 101 denotes a control device, 102 denotes a device A, and 103 denotes an insertion / removal storage device. These devices are connected to an IEEE 1394 bus having a hot-swap function. Further, in the insertion / removal storage device 103, reference numeral 104 denotes an insertion / removal detection unit, and reference numeral 105 denotes an insertion / removal storage unit. FIG. 2 shows a module configuration of the control device 101 and the insertion / removal storage device 103.
[0027]
The control device 101 controls devices connected to the IEEE 1394 bus, and transmits and receives video data and the like by synchronous or asynchronous transfer. For example, a device such as a PC equipped with an OS that supports hot-swapping is typical, and the present embodiment will be described on the assumption that the device is a PC. The device A 102 and the insertion / removal storage device 103 operate under the control of another control device 101 connected to the IEEE 1394 bus, and transmit and receive video data and the like to and from other devices by synchronous or asynchronous transfer.
[0028]
First, an insertion / removal detection method mounted on a general control device 101 will be described. The control device 101 detects a bus reset occurring on the IEEE 1394 bus in the IEEE 1394 interface card. From the IEEE 1394 interface card, the result is sent to the OS of the control device 101 as an event. In this case, if the OS can respond to the event, it recognizes that a device on the IEEE 1394 bus has been inserted or removed. In this case, the control device 101 checks what device is connected to the IEEE 1394 bus, and changes the processing content in a new device connection environment. 2, a dotted line indicates an event from the IEEE 1394 interface card in the control device. The bus reset is detected by an IEEE 1394 interface card, which is hardware, and a hardware interrupt is sent to a higher-order device driver. The application is notified as an event via the higher-level OS. At this point, the application will detect that a bus reset has occurred.
[0029]
Since this bus insertion / removal detection method cannot detect all bus resets, a detection method according to the present invention will be described. In FIG. 1, the insertion / removal storage device 103 detects a bus reset occurring when a device is inserted / removed on the IEEE1394 bus to which the insertion / removal detection unit 104 is connected, and stores the bus reset in the insertion / removal storage unit 103. The insertion / removal storage device is provided with a command for reading a result stored in the insertion / removal storage unit 105 from a device connected to IEEE 1394. The control device 101 checks the storage of the bus reset with respect to the insertion / removal storage device 103 at regular intervals. If the insertion and removal storage unit 105 stores that the bus reset has occurred, it is possible to recognize that the bus reset has occurred. More specifically, the application of the control device 101 reads the insertion / removal storage stored in the hardware of the insertion / removal storage device 103 via the IEEE 1394 bus using the protocol on IEEE 1394.
[0030]
Further, processing when software is installed in the control device will be described with reference to the flowchart of FIG. The flowchart in FIG. 3A is a task for reading data from an insertion / removal storage device, which is a method newly provided in the present invention. The flowchart of FIG. 3B is a task of detecting an OS standard bus reset and notifying an event. Starting from the task of FIG. 3A, S101 is a start step, S102 is an insertion / removal storage means reading step, S103 is an insertion / removal determination step, S104 is a processing step after device insertion / removal, and S105 is a wait step. The start step S101 is the start of the process. The insertion / removal storage means readout step S102 is a step for reading out the insertion / removal storage device 103. The insertion / removal determination S103 is a step of determining whether or not the insertion / removal has occurred. If the result read out in the insertion / removal storage means reading step S102 detects a bus reset, it is determined that the insertion / removal has occurred. The process proceeds to step S104. Conversely, if no insertion or removal has occurred, the process proceeds to the wait step S105. In the wait step S105, after a predetermined time has elapsed, the process proceeds to the insertion / removal storage unit reading step S102.
[0031]
Next, the task in FIG. 3B will be described. S201 is a start step, S202 is an insertion / removal event waiting step, S203 is an insertion / removal storage device determination step, and S204 is a processing step after device insertion / removal. The start step S201 is the start of the process. An insertion / extraction event waiting step S202 waits until an insertion / extraction event occurs. If an insertion / extraction event occurs, the process proceeds to an insertion / extraction storage device determination step S203. The insertion / removal storage device determination step S203 determines whether the insertion / removal storage device 103 has been removed based on the result of device insertion / removal. If the insertion / removal storage device 103 has not been removed, the process proceeds to an insertion / removal event waiting step S202. The process proceeds to the step S204 when the insertion / removal storage device 103 has been removed. The reason for performing this branch is that if the insertion / removal storage device 103 exists, the insertion / removal is detected by the task of FIG. 3A, and the event detected by the task of FIG. 3B is not used. is there. This prevents double processing after device insertion / removal.
[0032]
As described above, by providing the insertion / removal detection means 104 and the insertion / removal storage means 105 in the insertion / removal storage device 103, the fact that the bus reset is detected is stored, and by reading out the control device 101 at regular intervals, the bus can be surely transmitted. A reset can be detected.
[0033]
In the embodiments of the present invention, a storage medium for storing a program to be executed by a computer for all or a part of the function of each unit described above may be used. Although the control device has been described using a PC, any device having a control function, such as a camera or a VTR, can achieve the same effect. As an example of realizing an application, an OS standard event is used in combination, but in a system that always uses an insertion / removal storage device, an OS standard event may not be used at all. Although the description has been made using the IEEE 1394 bus, a similar effect can be obtained in a bus having another insertion / removal function, for example, a USB (Universal Serial Bus).
[0034]
【The invention's effect】
As described above, according to the present invention, by adding a function to a newly developed device, an advantageous effect that the device insertion / removal can be reliably detected even when the conventional device / standard is used as it is can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration according to an embodiment of the present invention; FIG. 2 is a configuration diagram of software and hardware for describing an embodiment of the present invention; FIG. FIG. 4 is a block diagram showing the configuration of a conventional data transfer device.
101 Control device 102 Device A
103 insertion / extraction storage device 104 insertion / extraction detection means 105 insertion / extraction storage means S101 start step S102 insertion / extraction storage means reading step S103 insertion / extraction determination step S104 processing after device insertion / extraction S201 start step S202 insertion / extraction event waiting step S203 insertion / extraction storage device determination step S204 after device insertion / extraction Processing 200 interface card 201 interface circuit 202 buffer memory 203 link layer circuit 204 physical layer circuit 205 port circuit 206 analyzer 207 MPU

Claims (10)

A control device for controlling other devices on a bus having a hot-swap function, an insertion / removal detection means for detecting device insertion / removal on the bus, and an insertion / removal storage device comprising an insertion / removal storage means for storing a result detected by the insertion / removal detection means Is a data transfer device to be connected,
When device insertion / removal occurs on the bus,
The insertion / removal detection means detects device insertion / removal on the bus,
The fact that the device has been inserted and removed is stored in the insertion and removal storage means,
The control device, by reading the presence or absence of device insertion and removal in the insertion and removal storage means of the insertion and removal detection device,
A data transfer device for detecting insertion and removal of a device on the bus. The insertion / extraction detection means,
2. The data transfer device according to claim 1, wherein the device is determined to be inserted or removed by a bus reset on the bus. 3. The data transfer device according to claim 1, wherein the control device reads the presence / absence of device insertion / removal from the insertion / removal storage unit of the insertion / removal detection device at predetermined time intervals. 4. The data transfer device according to claim 3, wherein the predetermined time interval is set to be equal to or longer than a time required for the bus reset state to converge. 5. The data transfer device according to claim 4, wherein said insertion / removal detection means stores a bus reset generated within a predetermined time as one device insertion / removal. 6. The data transfer device according to claim 5, wherein the predetermined time is set to be equal to or longer than a time required for the bus reset state to converge. 7. The data transfer device according to claim 6, wherein the control device invalidates a device insertion / removal event detected in the control device when the insertion / removal storage device is present. The data transfer device according to claim 7, wherein the bus is an IEEE 1394 bus. 9. The data transfer device according to claim 8, wherein the control device reads the presence or absence of device insertion / removal from the insertion / removal storage unit of the insertion / removal detection device by asynchronous transfer. 10. The data transfer device according to claim 9, wherein the control device reads the presence / absence of device insertion / removal from the insertion / removal storage unit of the insertion / removal detection device using an IEEE1394 standard AV / C command.

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