JP6008380B2 - BUS CONTROL DEVICE, ITS CONTROL METHOD, AND PROGRAM - Google Patents

Description

  The present invention relates to a bus control device, a control method thereof, and a program, and more particularly to a bus control device for a serial bus capable of hot swapping, a control method thereof, and a program.

  In order to connect a plurality of slave devices to a computer system, a connection method via a serial bus is utilized. In particular, in an embedded system such as a mobile phone, a connection method for connecting a plurality of slave devices via a single serial bus is often employed. However, in such a connection method, a transmission delay may occur when each slave device transmits and receives a signal.

  Here, Patent Document 1 discloses a technique for solving a transmission delay with a master node by adjusting the phase of a signal by a slave node.

JP 2008-16955 A

  The disclosure of the above prior art document is incorporated herein by reference. The following analysis has been made from the viewpoint of the present invention.

  As described above, a transmission delay may occur when data is transmitted / received to / from a plurality of slave devices via the serial bus. In addition, the operation margin for each slave device may be biased due to hot swapping. This is because a change in bus load capacity and a transmission delay occur as the connection state of the slave device changes. Here, hot swapping refers to executing connection and disconnection of a slave device with the power turned on.

  Patent Document 1 discloses a technique for communicating with a master node without interrupting transmission in switching of a slave node that transmits and receives signals. Here, Patent Document 1 discloses a technique in which a slave node controls the phase of a data signal. However, Patent Document 1 does not consider securing an operation margin when hot swapping is performed.

  Therefore, when data is transferred via a serial bus that can be hot swapped, a bus control device that controls data transfer timing, a control method therefor, and a program are desired.

According to the first aspect of the present invention, a data communication unit that communicates with one or two or more slave devices via a serial bus capable of hot swapping, and a connection state of each slave device to the serial bus A transfer timing determination unit for determining a data transfer timing value for each slave device, a transfer timing storage unit for storing the transfer timing value, and a data transfer timing value for each slave device based on the transfer timing value. And a transfer timing control unit that controls transfer , wherein the connection state change includes changing the connection state based on hot swap of the serial bus .
According to another aspect of the present invention, a data communication unit that communicates with one or more slave devices via a serial bus that is hot-swappable, and a state in which each slave device is connected to the serial bus. A transfer timing determination unit that determines a data transfer timing value for each slave device, a transfer timing storage unit that stores the transfer timing value, and a data transfer to each slave device based on the transfer timing value And a transfer timing control unit that controls the transfer timing storage unit, wherein the transfer timing storage unit stores the transfer timing value in association with the address of each slave device. The

According to a second aspect of the present invention, there is provided a control method for a bus control device including a data communication unit that communicates with one or more slave devices via a serial bus capable of hot swapping. Based on a connection state of the slave device to the serial bus, a determination step of determining a transfer timing value for each slave device, a step of storing the transfer timing value, and a transfer timing value to each slave device viewed including the step, the controlling the transfer of data, the change of the connection state, on the basis of the serial bus hot-swap control method of the bus control device includes changing the connection state is provided.
According to another aspect of the present invention, there is provided a method for controlling a bus control device including a data communication unit that communicates with one or more slave devices via a serial bus capable of hot swapping, wherein each slave A determination step of determining a transfer timing value for each slave device based on a connection state of the device to the serial bus, a step of storing the transfer timing value, and a transfer to the slave device based on the transfer timing value see containing and controlling the transfer of data, and in the step of storing the transfer timing value, the relative address of each slave device, the bus control and storing, in association with the transfer timing values An apparatus control method is provided.

According to a third aspect of the present invention, for a computer that controls a bus control device including a data communication unit that communicates with one or more slave devices via a serial bus capable of hot swapping, Based on the connection state of each slave device to the serial bus, a determination process for determining a transfer timing value for each slave device, a process for storing the transfer timing value, and each slave device based on the transfer timing value And a process for controlling the transfer of data to the network, wherein the connection state change includes changing the connection state based on hot swap of the serial bus .
According to another aspect of the present invention, for each computer that controls a bus control device including a data communication unit that communicates with one or more slave devices via a serial bus that is hot swappable, Based on the connection state of the slave device to the serial bus, a determination process for determining a transfer timing value for each slave device, a process for storing the transfer timing value, and a process for storing the transfer timing value to each slave device And a process for controlling the transfer of the data, and in the process for storing the transfer timing value, the transfer timing value is stored in association with the address of each slave device. Is provided. Note that these programs can be recorded on a computer-readable storage medium. That is, the present invention can be embodied as a computer program product.

  Therefore, according to each aspect of the present invention, there is provided a bus control device that controls data transfer timing, a control method thereof, and a program when transferring data via a serial bus capable of hot swapping. Is done.

It is a figure for demonstrating one Embodiment of this invention. It is a figure which shows an example of a system structure provided with the bus control apparatus 1 which concerns on the 1st Embodiment of this invention. 2 is a diagram illustrating an example of an internal configuration of a bus control device 1. FIG. 6 is a diagram illustrating an example of a transfer timing table 15. FIG. It is a flowchart of a training process. 6 is a diagram illustrating an example of determination of a transfer timing value 110. FIG. It is a flowchart of the data transfer process after training. It is a flowchart of a hot swap detection process. 2 is a diagram illustrating an example of an internal configuration of a bus control device 1. FIG.

  First, an outline of an embodiment will be described with reference to FIG. In this summary, the drawing reference numbers are added for convenience to each element as an example for facilitating understanding, and are not intended to limit the present invention to the illustrated embodiment.

  As described above, hot swap causes a bias in the operation margin for each slave device. Therefore, when data is transferred via a serial bus that can be hot swapped, a bus control device that controls data transfer timing, a control method therefor, and a program are desired.

  Therefore, as an example, the bus control device 1 shown in FIG. 1 is provided. The bus control device 1 shown in FIG. 1 is connected to a data communication unit 10 that communicates with one or more slave devices 3 via a serial bus 2 that is hot swappable, and the slave devices 3 are connected to the serial bus. Based on the transfer timing determination unit 11 that determines the data transfer timing value 110 for each slave device 3, the transfer timing storage unit 12 that stores the transfer timing value 110, and the transfer timing value 110, And a transfer timing control unit 13 that controls data transfer.

  Here, the computer system 4 includes a bus control device 1 and a serial bus 2. The bus control device 1 and the serial bus 2 are connected. Here, the serial bus 2 can be hot swapped. That is, the computer system 4 can change the connection state of the slave device 3 during operation.

  First, the bus control device 1 includes a data communication unit 10. The data communication unit 10 transmits / receives data to / from the slave device 3.

  The bus control device 1 also includes a transfer timing determination unit 11. The transfer timing determination unit 11 determines the transfer timing of data with each slave device 3. As described above, depending on the connection state of the slave device 3, the operation margin for each slave device 3 is biased. Therefore, the transfer timing determination unit 11 executes a test (hereinafter, training) for determining the data transfer timing in advance of the data transfer.

  Then, the transfer timing determination unit 11 determines an optimal transfer timing value 110 based on the training result. Here, the transfer timing determination unit 11 determines the transfer timing of data that can secure an operation margin. Note that the operation margin here is an operation margin with respect to the setup time and the hold time.

  Further, the bus control device 1 includes a transfer timing storage unit 12. The transfer timing storage unit 12 stores a transfer timing value 110.

  The bus control device 1 includes a transfer timing control unit 13. The transfer timing control unit 13 switches the data transfer timing based on the transfer timing value 110. Then, the data communication unit 10 transfers data to each slave device 3.

  As described above, the bus control device 1 trains the transfer timing value 110 according to the connection state of the slave device 3. In addition, the bus control device 1 adjusts the data transfer timing even when a hot swap occurs. That is, the bus control device 1 can ensure an operation margin regardless of the connection state of the slave devices.

  Therefore, the present invention can provide a bus control device, a control method thereof, and a program for controlling the data transfer timing when transferring data via a serial bus capable of hot swapping.

  Hereinafter, specific embodiments will be described in more detail with reference to the drawings.

[First Embodiment]
The first embodiment of the present invention will be described in more detail with reference to the drawings.

  FIG. 2 is a diagram illustrating an example of a system configuration including the bus control device 1 according to the first embodiment of the present invention.

  A computer system 4 shown in FIG. 2 includes a bus control device 1, a serial bus 2, and a slave node 5. The computer system 4 can be connected to one or more slave devices 3. Further, the slave node 5 executes connection processing and disconnection processing of the slave device 3 based on hot swap. In FIG. 2, only the modules related to the computer system 4 according to the present embodiment are shown for simplicity. The bus control device 1, serial bus 2, and slave device 3 are as described above. Therefore, further explanation is omitted.

  Next, FIG. 3 is a diagram illustrating an example of an internal configuration of the bus control device 1.

  The bus control device 1 includes a data communication unit 10, a transfer timing determination unit 11, a transfer timing storage unit 12, a transfer timing control unit 13, and a data communication control unit 14. FIG. 3 shows only modules related to the bus control device 1 according to the present embodiment for simplicity.

  The data communication unit 10 is as described above. Therefore, further explanation is omitted.

  The transfer timing determination unit 11 determines the transfer timing value 110 as described above. Here, the transfer timing determination unit 11 trains the transfer timing. Thereafter, the transfer timing determination unit 11 determines the transfer timing value 110 based on the training result. Here, the transfer timing determination unit 11 determines the transfer timing value 110 after training at the transfer timing of one or more patterns. In the following description, a training transfer timing pattern is represented as a training timing set 111. Furthermore, in the following description, the transfer timing for training is represented as a training timing value 112.

  Here, for example, it is preferable that the transfer timing determination unit 11 selects the median value from the training timing values 112 in which the communication is normal. This is because the transfer timing determination unit 11 can maximize the operation margin by selecting the median value.

  Furthermore, the transfer timing determination unit 11 determines whether the slave device 3 is connected based on the training result.

  The transfer timing storage unit 12 stores a transfer timing value 110. Here, it is assumed that the transfer timing storage unit 12 stores a transfer timing value 110 as the transfer timing table 15.

  Further, the transfer timing storage unit 12 registers the training timing set 111 in the transfer timing table 15.

  Further, the transfer timing storage unit 12 registers the training state value 113 in the transfer timing table 15. The training state value 113 is a value representing whether or not training is performed on each slave device.

  In addition, the transfer timing storage unit 12 registers the connection state value 114 of each slave device 3 in the transfer timing table 15. The connection state value 114 is a value indicating whether or not a slave device is connected.

  The transfer timing storage unit 12 registers the above information in the transfer timing table 15 in association with the slave device identifier 115. Here, the slave device identifier 115 is information for identifying each slave device 3. For example, the address of the slave device 3 is preferable as the slave device identifier 115. Alternatively, the bus control device 1 may assign an index to 3 in advance as a slave device identifier 115 to the slave device. Here, the type of the slave device identifier 115 is not limited as long as it is information that can distinguish the slave device 3.

  Here, FIG. 4 is a diagram illustrating an example of the transfer timing table 15.

  In the transfer timing table 15 of FIG. 4, slave_device1 is registered as the slave device identifier 115. Information is registered in the transfer timing table 15 of FIG. 4 in association with slave_device1.

  First, in the transfer timing table 15 of FIG. 4, the setup time setup_time1 and the hold time hold_time1 are registered as the transfer timing value 110.

  In addition, a training timing set 111 for the setup time and hold time is registered in the transfer timing table 15 of FIG. In the transfer timing table 15 of FIG. 4, s1_1, s1_2, and s1_3 are registered as the timing set 111 for training with respect to the setup time. In the transfer timing table 15 of FIG. 4, h1_1, h1_2, and h1_3 are registered as the training timing set 111 for the hold time.

  In the transfer timing table 15 of FIG. 4, “trained” is registered as the training state value 113.

  Furthermore, in the transfer timing table 15 of FIG. 4, the corresponding slave device 3 is registered as “connected” as the connection state value 114.

  Further, the transfer timing control unit 13 switches the data transfer timing based on the transfer timing value 110 as described above. Therefore, the computer system 4 does not need to execute processing for ensuring an operation margin in each slave node 5.

  The data communication control unit 14 performs data transmission / reception in the computer system 4.

  Next, the operation of the bus control device 1 will be described.

  First, the training process will be described with reference to the flowchart of FIG.

  First, the transfer timing determination unit 11 refers to the transfer timing table 15. Next, the transfer timing determination unit 11 confirms the training state value 113 based on the slave device identifier 115. Thereafter, the transfer timing determination unit 11 determines whether or not training is not performed on the target slave device 3 (step S110).

  When the condition of step S110 is satisfied, the transfer timing determination unit 11 acquires the training timing set 111 from the transfer timing table 15. Then, the transfer timing determination unit 11 sequentially selects the training timing value 112 from the training timing set 111. Thereafter, the transfer timing determination unit 11 sets the training timing value 112 in the transfer timing control unit 13 (step S111).

  Next, the data communication unit 10 transmits / receives data to / from the slave device 3 (step S112). At that time, the transfer timing control unit 13 controls the data transfer timing. Here, the data transfer timing is the training timing value 112. And training shall be performed about each of the setup time and hold time of data.

  Then, the transfer timing control unit 13 changes the training timing value 112 and repeats data transmission / reception. At that time, the transfer timing determination unit 11 determines whether or not data transmission / reception has been trained with all the training timing values 112 (step S113). If the condition of step S113 is not satisfied, the bus control device 1 repeats the processes of step S111 and step S112.

  On the other hand, when the condition of step S113 is satisfied, the transfer timing determination unit 11 determines whether or not there is a training timing value 112 for which communication was normal (step S114). When the condition of step S114 is satisfied, the transfer timing determination unit 11 determines the data transfer timing value 110 (step S115). For example, it is preferable that the transfer timing determination unit 11 selects the median value from the training timing values 112 for which communication was normal. This is because the transfer timing determination unit 11 can maximize the operation margin by selecting the median value.

  Thereafter, the transfer timing storage unit 12 registers the transfer timing value 110 in the transfer timing table 15 (step S116). In addition, the transfer timing storage unit 12 registers the training state value 113 in the transfer timing table 15. Further, the transfer timing storage unit 12 registers the connection state value 114 in the transfer timing table 15.

  On the other hand, when the condition of step S114 is not satisfied, the transfer timing determination unit 11 determines that the target slave device 3 is not connected (step S117). Also in this case, the transfer timing storage unit 12 registers the training state value 113 in the transfer timing table 15. Further, the transfer timing storage unit 12 registers the connection state value 114 in the transfer timing table 15.

  Then, the bus control device 1 executes the above training for all the slave devices 3. At that time, the transfer timing determination unit 11 refers to the transfer timing table 15 and confirms the training state of the slave device 3.

  Here, when no hot swap occurs, the bus control device 1 does not need to re-execute training. This is because the bus control device 1 holds the value of the transfer timing table 15 until the computer system 4 is reset. On the other hand, when a hot swap occurs, the bus control device 1 updates the value of the transfer timing table 15 by a method described later.

  Here, the determination of the transfer timing value 110 will be described with reference to FIG. First, FIGS. 6 (a-1) to 6 (a-5) are diagrams showing hold times for each training timing value 112. FIG. On the other hand, FIG. 6B is a diagram showing a data reception result for each hold time. For example, in the case of FIG. 6A-1, the hold time is T1. In addition, from FIG. 6B, the reception result in that case is abnormal. In the case of FIG. 6A-5, the hold time is T5. From FIG. 6B, the reception result in that case is abnormal. On the other hand, from FIG. 6B, when the data hold time is T2, T3, T4, the reception result is normal. Here, among the hold times of T2, T3, and T4, T3 is a median value (see FIG. 6 (a-2) to FIG. 6 (a-4)).

  Here, as described above, it is preferable to determine the transfer timing value so that the operation margin is maximized. Therefore, it is preferable to select the median value from the training timing values 112 for which communication was normal. Therefore, in the case of FIG. 6, it is preferable to select the hold time T3 as the transfer timing value 110 of the hold time.

  Next, data transfer processing after training will be described using the flowchart of FIG.

  First, the bus control device 1 confirms whether communication with the target slave device 3 is possible (step S210). At that time, the bus control device 1 refers to the connection state value 114 of the transfer timing table 15. Then, the transfer timing determination unit 11 determines whether or not hot swap has occurred (step S211). At that time, the transfer timing determination unit 11 periodically communicates with all the slave devices 3. Note that the transfer timing determination unit 11 also communicates with the slave device 3 that is determined to be unconnected. This is because the transfer timing determination unit 11 detects hot swap of the slave device 3.

  Here, when the condition of step S211 is not satisfied, the transfer timing determination unit 11 determines whether or not there is a communication request from the data communication control unit 14 to the target slave device 3 (step S212). If the condition of step S212 is not satisfied, the transfer timing determination unit repeats the determination of S211.

  On the other hand, when the condition of step S212 is satisfied, the transfer timing determination unit 11 acquires the transfer timing value 110 (step S213). At that time, the transfer timing determination unit 11 refers to the transfer timing table 15. Then, the transfer timing determination unit 11 sets the transfer timing value 110 in the transfer timing control unit 13. Thereafter, the data communication unit 10 transmits data to the slave device 3 (step S214). At that time, the transfer timing control unit 13 controls the data transfer timing.

  Next, a case where the condition of step S211 is satisfied will be described. That is, the hot swap detection process will be described.

  The hot swap detection process will be described with reference to the flowchart of FIG.

  First, the transfer timing determination unit 11 performs training for the unconnected slave device 3 (step S310). Then, the transfer timing determination unit 11 determines whether or not there is a response from the slave device 3 that has been determined to be unconnected (step S311). This is because the newly connected slave device 3 is detected by hot swap.

  Here, it is assumed that the condition of step S311 is satisfied. In this case, the transfer timing determination unit 11 determines that the target slave device 3 is connected (step S312). Then, the transfer timing storage unit 12 registers information indicating “connected” in the connection state value 114 of the transfer timing table 15 (step S313).

  On the other hand, consider a case where the condition of step S311 is not satisfied. In this case, the transfer timing determination unit 11 determines whether or not there is a response from the slave device 3 that has been determined to be connected (step S314). This is because the disconnected slave device 3 is detected by hot swap.

  If the condition in step S314 is satisfied, the process proceeds to step S212. On the other hand, when the condition of step S314 is not satisfied, the transfer timing determination unit 11 determines that the target slave device 3 is disconnected (step S315). Then, the transfer timing storage unit 12 registers information indicating “no connection” in the connection state value 114 of the transfer timing table 15 (step S316).

  After the process of step S313 or the process of step S316, the transfer timing determination unit 11 initializes a value associated with the target slave device 3 in the transfer timing table 15 (step S317). Subsequently, the process of step S317 is also executed for all slave devices on the serial bus 2 to which the target slave device 3 is connected. Then, the process proceeds to step S110. That is, the bus control device 1 re-executes training.

  As described above, the first effect of the bus control device 1 according to the present embodiment is that it is possible to ensure an operation margin that matches the connection state of the slave devices. This is because the transfer timing that can ensure the operation margin of the setup time and the hold time is trained in advance.

  The second effect of the bus control device 1 according to the present embodiment is that the operation margin is not biased even when the connection state of the slave device is changed by hot swapping. This is because hot swap is detected and the data transfer timing is updated. Therefore, even when hot swap occurs, the bus control device having the first effect can be provided.

[Second Embodiment]
Next, the second embodiment will be described in detail with reference to the drawings.

  In the present embodiment, hot swap can be immediately detected. In the description of the present embodiment, the description of the same parts as those in the first embodiment is omitted. Further, in the description of the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As described above, in the present invention, the bus control device 1 trains data transfer timing in advance. Based on the training result, the bus control device 1 determines the transfer timing. Therefore, the bus control device 1 can transfer data while ensuring an operation margin. When a hot swap occurs, the bus control device 1 updates the transfer timing.

  However, the bus control device 1 according to the first embodiment needs to periodically communicate with all the slave devices 3 in order. Therefore, the bus control device 1 according to the first embodiment cannot immediately detect the occurrence of hot swap. Therefore, the bus control device 1 according to the present embodiment is provided with a bus control device including a hot swap detection unit 16 that detects hot swap of a slave device.

  Here, FIG. 9 is a diagram illustrating an internal configuration of the bus control device 1 according to the present embodiment.

  As shown in FIG. 9, the bus control device 1 according to the present embodiment includes a hot swap detection unit 16. The hot swap detection unit 16 is connected to a signal for monitoring the connection state from the slave device 3. Therefore, the bus control device 1 according to the present embodiment can immediately detect hot swap.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and further modifications, substitutions, and adjustments may be made without departing from the basic technical idea of the present invention. Can be added. For example, in the above description of the embodiment, the serial bus 2 has been described, but a plurality of serial buses 2 may be provided.

  In the above-described embodiment, the connection confirmation is performed once for confirmation of disconnection of the slave device 3. However, it may be determined that the slave device 3 is disconnected after two or more connection confirmations.

  A part or all of the above embodiments can be described as in the following supplementary notes, but is not limited thereto.

(Additional remark 1) Based on the data communication part which communicates with one or two or more slave devices via the serial bus which can be hot-swapped, and each said slave device based on the connection state to the said serial bus of each said slave device A transfer timing determination unit for determining a transfer timing value of data for the transfer, a transfer timing storage unit for storing the transfer timing value,
A bus control device comprising: a transfer timing control unit that controls transfer of data to each of the slave devices based on the transfer timing value.

  (Additional remark 2) The said transfer timing value is a bus control apparatus which is the information showing the setup time and hold time in the case of transferring data.

  (Supplementary Note 3) The bus control device, wherein the transfer timing determination unit determines the transfer timing value after testing the transfer timing of data of one or more patterns.

  (Additional remark 4) The said transfer timing judgment part is a bus control apparatus which judges the said transfer timing value based on the operation margin with respect to a setup time and a hold time, after testing the transfer timing of the data of 1 or 2 or more patterns.

  (Additional remark 5) The said transfer timing judgment part is a bus control apparatus which updates the said transfer timing value with the change of the connection state to the said serial bus of each said slave device.

  (Additional remark 6) The said transfer timing judgment part communicates with each said slave device regularly, The bus control apparatus which detects the change of the connection state to the said serial bus of each said slave device.

  (Additional remark 7) The said transfer timing storage part is a bus control apparatus which matches and stores the said transfer timing value with respect to the address of each said slave device.

  (Additional remark 8) The bus control apparatus further provided with the hot swap detection part which detects the hot swap of each said slave device.

(Supplementary Note 9) A method for controlling a bus control device including a data communication unit that communicates with one or more slave devices via a serial bus capable of hot swapping, to the serial bus of each slave device A determination step of determining a transfer timing value for each of the slave devices based on the connection state, and a step of storing the transfer timing value;
Controlling the transfer of data to each of the slave devices based on the transfer timing value.

  (Additional remark 10) The said determination process is a control method of the bus control apparatus which determines the said transfer timing value, after testing the transfer timing of the data of 1 or 2 or more patterns.

  (Additional remark 11) The said determination process is a control method of the bus control apparatus which determines the said transfer timing value based on the operation margin with respect to a setup time and a hold time, after testing the transfer timing of the data of 1 or 2 or more patterns .

  (Additional remark 12) The said determination process is a control method of the bus control apparatus which updates the said transfer timing value with the change of the connection state of each said slave device.

  (Additional remark 13) The said determination process is a control method of the bus controller which communicates with each said slave device regularly, and detects the change of the connection state to the said serial bus of each said slave device.

  (Additional remark 14) The control method of the bus control apparatus further including the process of detecting the hot swap of each said slave device.

  (Supplementary Note 15) The serial bus of each slave device to a computer that controls a bus control device including a data communication unit that communicates with one or more slave devices via a serial bus capable of hot swapping A determination process for determining a transfer timing value for each slave device based on a connection state to the slave, a process for storing the transfer timing value, and a control of data transfer to each slave device based on the transfer timing value And a program for executing the process.

  (Supplementary Note 16) The determination process is a program for determining the transfer timing value after testing the transfer timing of data of one or more patterns.

  (Additional remark 17) The said judgment process is a program which judges the said transfer timing value based on the operation margin with respect to a setup time and a hold time after testing the transfer timing of the data of 1 or 2 or more patterns.

  (Additional remark 18) The said determination process is a program which updates the said transfer timing value with the change of the connection state to the said serial bus of each said slave device.

  (Additional remark 19) The said determination process is a program which communicates with each said slave device regularly and detects the change of the connection state to the said serial bus of each said slave device.

  (Additional remark 20) The program which further contains the process which detects the hot swap of each said slave device.

  The disclosure of the cited patent document is incorporated herein by reference. Within the scope of the entire disclosure (including claims) of the present invention, the embodiments and examples can be changed and adjusted based on the basic technical concept. Various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) within the scope of the claims of the present invention, Selection is possible. That is, the present invention of course includes various variations and modifications that could be made by those skilled in the art according to the entire disclosure including the claims and the technical idea.

DESCRIPTION OF SYMBOLS 1 Bus control apparatus 2 Serial bus 3 Slave device 4 Computer system 5 Slave node 10 Data communication part 11 Transfer timing judgment part 12 Transfer timing storage part 13 Transfer timing control part 14 Data communication control part 15 Transfer timing table 16 Hot swap detection part 110 Transfer timing value 111 Timing set for training 112 Timing value for training 113 Training state value 114 Connection state value 115 Slave device identifier

Claims (9)

A data communication unit that communicates with one or more slave devices via a hot-swappable serial bus;
Based on the connection state of each slave device to the serial bus, a transfer timing determination unit that determines a data transfer timing value for each slave device;
A transfer timing storage unit for storing the transfer timing value;
Based on the transfer timing value, a transfer timing control unit that controls transfer of data to the slave devices,
With
The bus control device, wherein the transfer timing storage unit stores the transfer timing value in association with the address of each slave device. The bus control device according to claim 1, wherein the transfer timing value is information indicating a setup time and a hold time when data is transferred. The transfer timing determining unit is 1 or after testing the transfer timing of data of two or more patterns, the bus control device according to claim 1 or 2, wherein determining the transfer timing value. The transfer timing determination unit, after testing the transfer timing of data of one or more patterns, set-up time, and based on the operation margin for a hold time, any one of claims 1 to 3 to determine the transfer timing values The bus control device according to one. The transfer timing determination unit, wherein with the change of the status of the connection to the serial bus of the slave device, the bus control device according to any one of claims 1 to 4 updates the transfer timing value. The transfer timing determining unit communicates with regularly each slave device, the bus control device according to any one of claims 1 to 5 for detecting a change in the connection state to the serial bus of each slave device . Bus control apparatus according to any one of claims 1 to 6 further comprising a hot-swap detecting section for detecting a hot swap of the respective slave device. A control method of a bus control device including a data communication unit that communicates with one or more slave devices via a serial bus that is hot-swappable,
A determination step of determining a transfer timing value for each slave device based on a connection state of each slave device to the serial bus;
Storing the transfer timing value;
Controlling the transfer of data to each of the slave devices based on the transfer timing value;
Including
In the step of storing the transfer timing value, the transfer timing value is stored in association with the address of each slave device. For a computer that controls a bus control device that includes a data communication unit that communicates with one or more slave devices via a serial bus that is hot swappable.
Based on the connection state of each slave device to the serial bus, a determination process for determining a transfer timing value for each slave device;
Processing for storing the transfer timing value;
A process for controlling the transfer of data to each of the slave devices based on the transfer timing value;
And execute
In the process of storing the transfer timing value, the program stores the transfer timing value in association with the address of each slave device.

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