Patent Description:
In recent years, the transfer speed of external recording devices, such as a memory card, is increasing. When a new standard is formulated, new transfer techniques are adopted, such as a change from parallel transfer to high-speed serial transfer, and an increase in frequencies, for example; as a result, the transfer speed increases.

Also, techniques to reduce a time period of initialization of a memory card have been proposed as in, for example, PTL1.

Prior art which relates to this field can be found in document <CIT>, disclosing a memory card, a host device, a memory card connector, and a memory card adapter. The memory card includes a first surface, a second surface, and 1st to Nth terminal groups. The first surface includes first to Nth rows, wherein N is an integer of two or greater. The second surface faces the opposite side from the first surface. The 1st to Nth terminal groups are placed in the first to Nth rows. The 1st terminal group includes terminals to which differential clock signals are assigned, terminals to which single-ended signals are assigned, and a terminal to which a first power supply voltage is assigned. Kth terminal group, wherein K is an integer no smaller than two and no greater than N, includes terminals to which differential data signals are assigned.

Further prior art can be found in document <CIT>, disclosing a communication speed control device and a communication speed control method.

It is desirable that a communication apparatus that reads and writes data by performing communication with an external recording device be compatible with the standards of a plurality of external recording devices via a single slot in view of, for example, area conservation and cost reduction. In this case, the communication apparatus needs to determine with which standard an external recording device inserted in the slot is compatible among the plurality of standards.

However, the technique of PTL1 is a technique that involves a single standard, and is not a technique for determining the standard with which the external recording device is compatible among the plurality of standards.

The present invention has been made in view of the foregoing situation, and provides a technique to appropriately determine with which standard an external recording device is compatible among a plurality of standards.

Objects of the present disclosure are achieved by what is defined in the appended independent claims. Advantageous modifications thereof are set forth in the appended dependent claims.

The present invention makes it possible to appropriately determine with which standard an external recording device is compatible among a plurality of standards.

Note that other features and advantages of the present invention will be more apparent from the accompanying drawings and the following description in the embodiments of the invention.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain principles of the invention.

Multiple features are described in the exemplary embodiments.

<FIG> is a block diagram of a communication apparatus that reads and writes data by communicating with an external recording device <NUM>. This communication apparatus can be mounted on, for example, an image capturing apparatus or the like. The communication apparatus includes a semiconductor apparatus <NUM>, an external recording device connector <NUM>, a common power source generation unit <NUM>, a second transfer mode power source generation unit <NUM>, and a third transfer mode power source generation unit <NUM>.

The semiconductor apparatus <NUM> records (writes) or reproduces (reads) data by communicating with the external recording device <NUM> via the external recording device connector <NUM>. For example, the semiconductor apparatus <NUM> is an LSI (Large Scale Integrated Circuit) mounted on a camera, a smartphone, a personal computer, or the like.

The external recording device connector <NUM> is a connector (connection unit) for connecting to the attachable and removable external recording device <NUM>, and includes an electrical contact for connecting the semiconductor apparatus <NUM> and the external recording device <NUM>. For example, the external recording device connector <NUM> is a slot for a recording medium. The external recording device <NUM> holds data processed by the semiconductor apparatus <NUM> in a ROM (Read Only Memory), and also transmits/receives data recorded in a ROM.

The semiconductor apparatus <NUM> and the external recording device <NUM> have a plurality of transfer modes with different transfer speeds. The semiconductor apparatus <NUM> judges with which transfer mode the external recording device <NUM> is compatible, and they perform transfer in the same transfer mode. A sequence for determining a transfer mode will be described later with reference to <FIG>. The present embodiment will be described using an exemplary case where the plurality of transfer modes with different transfer speeds are three transfer modes, namely a first transfer mode, a second transfer mode, and a third transfer mode.

The first transfer mode is a transfer mode whose transfer speed is lower than the transfer speeds of the second transfer mode and the third transfer mode. The second transfer mode is a transfer mode whose transfer speed is higher than the transfer speed of the first transfer mode and lower than the transfer speed of the third transfer mode. The third transfer mode is a transfer mode whose transfer speed is higher than the transfer speeds of the first transfer mode and the second transfer mode. Also, while the external recording device <NUM> includes an independent electrical terminal for the first transfer mode, it includes a shared electrical terminal for the second transfer mode and the third transfer mode. However, this electrical terminal configuration is merely an example; for example, all of the transfer modes may share the same electrical terminal.

The common power source generation unit <NUM> generates a power source that is commonly necessary when the external recording device <NUM> performs transfer in any transfer mode (a common power source). The second transfer mode power source generation unit <NUM> generates a power source that is necessary when the external recording device <NUM> performs transfer in the second transfer mode (a second transfer mode power source). The second transfer mode power source is not necessary when the external recording device <NUM> performs transfer in the first transfer mode or the third transfer mode. The third transfer mode power source generation unit <NUM> generates a power source that is necessary when the external recording device <NUM> performs transfer in the third transfer mode (a third transfer mode power source). The third transfer mode power source is not necessary when the external recording device <NUM> performs transfer in the first transfer mode or the second transfer mode.

In the following description, it is assumed that the first transfer mode is a transfer mode that conforms to the UHS-I standard, the second transfer mode is a transfer mode that conforms to the UHS-II standard, and the third transfer mode is a transfer mode that conforms to the SDExpress standard. It is assumed that the external recording device <NUM> supports the first transfer mode (UHS-I standard), and in some cases, supports at least one of the second transfer mode (UHS-II standard) and the third transfer mode (SDExpress standard) as an option. However, the present embodiment is not limited to various types of standards mentioned herein, and each transfer mode may be a transfer mode that conforms to another standard. For example, the second transfer mode may be a transfer mode that conforms to the UHS-III standard. Note that the first transfer mode (UHS-I standard) and the second transfer mode (UHS-II standard) are compatible, and the first transfer mode (UHS-I standard) and the third transfer mode (SDExpress standard) are compatible. However, the second transfer mode (UHS-II standard) and the third transfer mode (SDExpress standard) are not compatible. However, a part of signal lines (at least one signal line; for example, VDD1) is used as the same signal line in any of the first transfer mode (UHS-I standard), the second transfer mode (UHS-II standard), and the third transfer mode (SDExpress standard).

The semiconductor apparatus <NUM> includes a first recording control unit <NUM>, a first physical layer <NUM>, a second recording control unit <NUM>, a second physical layer <NUM>, a third recording control unit <NUM>, a third physical layer <NUM>, a signal line switching unit <NUM>, and a system control unit <NUM>.

The first recording control unit <NUM> is a controller in the first transfer mode, and is a logic circuit for processing data to be transmitted/received, generating a command for transmitting/receiving data, correcting an error in received data, and so on.

The first physical layer <NUM> is a physical layer in the first transfer mode, and is a circuit that converts logic signals for communication with the first recording control unit <NUM> into electrical signals for communication with the external recording device <NUM>. For example, the first physical layer <NUM> is composed of an LVCMOS (Low Voltage Complementary Metal Oxide Semiconductor). Also, communication between the first physical layer <NUM> and the external recording device <NUM> is performed using parallel signals.

The second recording control unit <NUM> is a controller in the second transfer mode, and is a logic circuit for performing processing for packetizing data to be transmitted/received, generating a command for transmitting/receiving data, correcting an error in received data, and so on.

The second physical layer <NUM> is a physical layer in the second transfer mode, and is a circuit that converts logic signals for communication with the second recording control unit <NUM> into electrical signals for communication with the external recording device <NUM>. For example, the second physical layer <NUM> is a PHY (physical layer) that has a SerDes (Serializer/Deserializer) function. Also, communication between the second physical layer <NUM> and the external recording device <NUM> is performed using serial signals.

The third recording control unit <NUM> is a controller in the third transfer mode, and is a logic circuit for performing processing for packetizing data to be transmitted/received, generating a command for transmitting/receiving data, correcting an error in received data, and so on. Also, the third recording control unit <NUM> can receive an input of a third transfer mode compatibility signal (a third signal), which indicates that the external recording device <NUM> is compatible with the third transfer mode, from a specific signal line (a third signal line). The supply of a power source from the third transfer mode power source generation unit <NUM> to the external recording device <NUM> serves as the trigger that enables the external recording device <NUM> to generate the third transfer mode compatibility signal. A specific sequence will be described later with reference to <FIG>, <FIG>, and <FIG>.

The third physical layer <NUM> is a physical layer in the third transfer mode, and is a circuit that converts logic signals for communication with the third recording control unit <NUM> into electrical signals for communication with the external recording device <NUM>. For example, the third physical layer <NUM> is a PHY (physical layer) that has a SerDes function. Also, communication between the third physical layer <NUM> and the external recording device <NUM> is performed using serial signals.

As stated earlier, the external recording device <NUM> uses a shared electrical terminal in the second transfer mode and the third transfer mode. It is therefore necessary to switch between the connection destinations of signal lines of serial signals (a first signal line and a second signal line) depending on the transfer mode to be used. The signal lines of serial signals (the first signal line and the second signal line) are selectively connected to the second physical layer <NUM> and the third physical layer <NUM> via the signal line switching unit <NUM>. The signal line switching unit <NUM> selects one of the second physical layer <NUM> and the third physical layer <NUM> in accordance with the transfer mode to be used, and connects the selected physical layer and the signal lines of serial signals of the external recording device connector <NUM> (the first signal line and the second signal line).

In accordance with the transfer mode with which the external recording device <NUM> is compatible, the system control unit <NUM> switches among the first recording control unit <NUM>, the second recording control unit <NUM>, and the third recording control unit <NUM> to be used. Also, when performing a transfer in each type of transfer mode, the system control unit <NUM> provides the common power source generation unit <NUM>, the second transfer mode power source generation unit <NUM>, and the third transfer mode power source generation unit <NUM> with an instruction for supplying a power source. Furthermore, with respect to the signal line switching unit <NUM>, the system control unit <NUM> performs control to switch between the use of signal lines of the second physical layer <NUM> and the use of signal lines of the third physical layer <NUM>. The system control unit <NUM> is, for example, a CPU (Central Processing Unit) or the like. A specific control sequence will be described later with reference to <FIG>, and <FIG>.

Although the signal line switching unit <NUM> is present in the semiconductor apparatus <NUM> in the example of <FIG>, it may be present outside the semiconductor apparatus <NUM>, that is to say, on a printed substrate of the communication apparatus, and the position thereof is not limited. Also, the semiconductor apparatus <NUM> may include, in place of the signal line switching unit <NUM>, an integrated physical layer (a multi-protocol PHY) in which the second physical layer <NUM> and the third physical layer <NUM> are integrated. In this case, the semiconductor apparatus <NUM> switches between signals of the second recording control unit <NUM> and signals of the third recording control unit <NUM> inside the integrated physical layer.

<FIG> are flowcharts of processing in which the communication apparatus determines the transfer mode with which the external recording device <NUM> is compatible in the first embodiment.

There are a plurality of determination methods for the third transfer mode, and the used determination method differs between <FIG> and <FIG> and <FIG> and <FIG>. In <FIG> and <FIG>, determination of the third transfer mode is made based on communication in the first transfer mode. In <FIG> and <FIG>, determination based on communication in a specific transfer mode is not made, and the supply of the third transfer mode power source serves as the trigger to make determination of the third transfer mode based on whether the third transfer mode compatibility signal is input. In the cases of <FIG> and <FIG>, as determination of the third transfer mode is made based on communication, the determination accuracy is improved. However, as it is necessary to execute initialization processing for the first transfer mode prior to determination of the third transfer mode, the time period required for determination processing is relatively long. On the other hand, in the cases of <FIG> and <FIG>, as determination of the third transfer mode is made without executing the initialization processing for the first transfer mode, the time period required for determination processing is relatively short, but the determination accuracy decreases.

In <FIG> and <FIG>, determination of the second transfer mode is preferentially made. In a case where the external recording device <NUM> is compatible with the second transfer mode, the second transfer mode is selected as the transfer mode to be used, regardless of whether the external recording device <NUM> is compatible with the third transfer mode. On the other hand, in <FIG> and <FIG>, determination of the third transfer mode is preferentially made. In a case where the external recording device <NUM> is compatible with the third transfer mode, the third transfer mode is selected as the transfer mode to be used, regardless of whether the external recording device <NUM> is compatible with the second transfer mode.

In general, determination of the second transfer mode can be executed in a shorter time period than determination of the third transfer mode. Therefore, in a default determination mode, the communication apparatus determines the transfer mode with which the external recording device <NUM> is compatible in line with the flowchart of <FIG>.

Also, the communication apparatus can display a menu screen for selecting a determination mode on a display unit (not shown), and a user can select a determination mode of the communication apparatus via this menu screen. Selection of the determination mode includes selection of a determination speed ("normal determination" or "high-speed determination"), and selection of a mode to be prioritized ("determination with priority on the second transfer mode" or "determination with priority on the third transfer mode").

The default determination mode mentioned earlier refers to the combination of "normal determination" and "determination with priority on the second transfer mode"; in this case, the communication apparatus determines the transfer mode with which the external recording device <NUM> is compatible in line with the flowchart of <FIG>. In a case where the combination of "high-speed determination" and "determination with priority on the second transfer mode" has been selected, the communication apparatus determines the transfer mode with which the external recording device <NUM> is compatible in line with the flowchart of <FIG>. In a case where the combination of "normal determination" and "determination with priority on the third transfer mode" has been selected, the communication apparatus determines the transfer mode with which the external recording device <NUM> is compatible in line with the flowchart of <FIG>. In a case where the combination of "high-speed determination" and "determination with priority on the third transfer mode" has been selected, the communication apparatus determines the transfer mode with which the external recording device <NUM> is compatible in line with the flowchart of <FIG>.

Note that the default determination mode is not limited to the combination of "normal determination" and "determination with priority on the second transfer mode". For example, in a case where external recording devices <NUM> that are compatible with the third transfer mode have been disseminated in larger numbers than external recording devices <NUM> that are not compatible with the third transfer mode, the combination of "normal determination" and "determination with priority on the third transfer mode" may be used as the default determination mode.

First, with reference to <FIG>, a description is given of determination processing for a case where the combination of "normal determination" and "determination with priority on the second transfer mode" has been selected as the determination mode. The system control unit <NUM> executes the overall control on the determination processing of <FIG> in line with a control program stored in a ROM (not shown), unless specifically stated otherwise. Processing of the flowchart of <FIG> is started when the system control unit <NUM> detects that the external recording device <NUM> has been connected to the external recording device connector <NUM>.

In S200, the system control unit <NUM> supplies the common power source to the external recording device <NUM> by issuing an instruction to the common power source generation unit <NUM>. In S201, the system control unit <NUM> supplies the second transfer mode power source to the external recording device <NUM> by issuing an instruction to the second transfer mode power source generation unit <NUM>.

In S202 to S204, the system control unit <NUM> performs control to determine whether the external recording device <NUM> is compatible with the second transfer mode. Specifically, in S202, the system control unit <NUM> performs control to connect the signal lines of the signal line switching unit <NUM> to the second physical layer <NUM>. In S203, the second recording control unit <NUM> outputs a second transfer mode determination signal from the second physical layer <NUM> to the external recording device <NUM>. In S204, the second recording control unit <NUM> determines whether a second transfer mode compatibility signal, which indicates that the external recording device <NUM> is compatible with the second transfer mode, has been input from the external recording device <NUM> before the elapse of a predetermined time period (a first time period) since the second transfer mode determination signal was output. In a case where the second transfer mode compatibility signal has been input, processing proceeds to S205; otherwise, processing proceeds to S206.

In a case where the second transfer mode conforms to the UHS-II standard or the UHS-III standard, the second transfer mode determination signal (a first signal) is STB. L, and the second recording control unit <NUM> outputs STB. L via a D0 lane (the first signal line). Also, the second transfer mode compatibility signal (a second signal) is STB. L, and in a case where STB. L has been input from a D1 lane (the second signal line), the second recording control unit <NUM> determines that the second transfer mode compatibility signal has been input. According to the standard, the determination takes up to <NUM>. That is to say, the predetermined time period (the first time period) in S204 is <NUM>.

In S205, the system control unit <NUM> starts initialization in the second transfer mode (second initialization processing). This enables communication with the external recording device <NUM> in the second transfer mode. That is to say, in a case where the second initialization processing has been executed, the second recording control unit <NUM> communicates with the external recording device <NUM> in the second transfer mode.

In S206, the system control unit <NUM> stops the supply of the second transfer mode power source to the external recording device <NUM> by issuing an instruction to the second transfer mode power source generation unit <NUM>.

In S207, the system control unit <NUM> starts initialization in the first transfer mode (first initialization processing). In S208, the first recording control unit <NUM> issues a third transfer mode determination command from the first physical layer. As it is necessary to execute the first initialization processing to issue the third transfer mode determination command, a relatively long time period (e.g., a few hundred ms) is required from the start of the first initialization processing in S207 to the issuance of the third transfer mode determination command in S208. In S209, the first recording control unit <NUM> determines whether the external recording device <NUM> is compatible with the third transfer mode based on a third transfer mode determination response. In a case where the external recording device <NUM> is compatible with the third transfer mode, processing proceeds to S210; otherwise, processing proceeds to S213.

In a case where the first transfer mode conforms to the UHS-I standard and the third transfer mode conforms to the SDExpress standard, the third transfer mode determination command is CMD8. Also, the third transfer mode determination response is a response to CMD8, and includes information indicating whether the external recording device <NUM> is compatible with the third transfer mode. In this way, the execution of the first initialization processing enables communication in the first transfer mode, and determination of the third transfer mode is made based on communication of the command and the response.

In S210, the system control unit <NUM> selects the third physical layer <NUM> by issuing an instruction to the signal line switching unit <NUM>. In S211, the system control unit <NUM> supplies the third transfer mode power source to the external recording device <NUM> by issuing an instruction to the third transfer mode power source generation unit <NUM>. In S212, the third recording control unit <NUM> performs reinitialization in the third transfer mode. The initialization in the third transfer mode (third initialization processing) enables communication with the external recording device <NUM> in the third transfer mode. That is to say, in a case where the third initialization processing has been executed, the third recording control unit <NUM> communicates with the external recording device <NUM> in the third transfer mode.

In S213, the first recording control unit <NUM> continues initialization in the first transfer mode. Note that as stated earlier, the first initialization processing, which is necessary for the first recording control unit <NUM> to perform communication in the first transfer mode, was already executed at the time of S208. Therefore, the continuation of initialization in S213 refers to processing that is different from the first initialization processing.

Next, with reference to <FIG>, a description is given of determination processing for a case where the combination of "high-speed determination" and "determination with priority on the second transfer mode" has been selected as the determination mode. The system control unit <NUM> executes the overall control on the determination processing of <FIG> in line with a control program stored in the ROM (not shown), unless specifically stated otherwise. Processing of the flowchart of <FIG> is started when the system control unit <NUM> detects that the external recording device <NUM> has been connected to the external recording device connector <NUM>.

Processing of S214 to S220 is similar to processing of S200 to S206 in <FIG>, and thus a description thereof is omitted.

In S221 to S223, the system control unit <NUM> performs control to determine whether the external recording device <NUM> is compatible with the third transfer mode. Specifically, in S221, the system control unit <NUM> performs control to connect the signal lines of the signal line switching unit <NUM> to the third physical layer <NUM>. In S222, the system control unit <NUM> supplies the third transfer mode power source to the external recording device <NUM> by issuing an instruction to the third transfer mode power source generation unit <NUM>. This is because a determination method different from that of <FIG> is used for determination of the third transfer mode, and the supply of the third transfer mode power source becomes the trigger for the external recording device <NUM> to respond with the third transfer mode compatibility signal. In S223, the third recording control unit <NUM> determines whether the third transfer mode compatibility signal, which indicates that the external recording device <NUM> is compatible with the third transfer mode, has been input from the external recording device <NUM> before the elapse of a predetermined time period (a second time period) since the third transfer mode power source was supplied. In a case where the third transfer mode compatibility signal has been input, processing proceeds to S224; otherwise, processing proceeds to S225. The time period from S222 to S223 is shorter than the time period from S207 to S208 in <FIG>, and is, for example, a few ms.

In a case where the third transfer mode conforms to the SDExpress standard, the third transfer mode compatibility signal is input from a CLKREQ signal line (a third signal line). Once the power source dedicated to SDExpress (the third transfer mode power source) has been supplied, a response is input to the CLKREQ signal line. It takes up to <NUM> to make a response. That is to say, the predetermined time period (the second time period) in S223 is <NUM>.

In S224, the third recording control unit <NUM> starts initialization in the third transfer mode (third initialization processing). This enables communication with the external recording device <NUM> in the third transfer mode. That is to say, in a case where the third initialization processing has been executed, the third recording control unit <NUM> communicates with the external recording device <NUM> in the third transfer mode.

In S225, the system control unit <NUM> stops the supply of the third transfer mode power source to the external recording device <NUM> by issuing an instruction to the third transfer mode power source generation unit <NUM>. In S226, the system control unit <NUM> starts initialization in the first transfer mode.

Next, with reference to <FIG>, a description is given of determination processing for a case where the combination of "normal determination" and "determination with priority on the third transfer mode" has been selected as the determination mode. The system control unit <NUM> executes the overall control on the determination processing of <FIG> in line with a control program stored in the ROM (not shown), unless specifically stated otherwise. Processing of the flowchart of <FIG> is started when the system control unit <NUM> detects that the external recording device <NUM> has been connected to the external recording device connector <NUM>.

Processing of S227 is similar to processing of S200 in <FIG>, and thus a description thereof is omitted. Processing of S228 to S233 is similar to processing of S207 to S212 in <FIG>, and thus a description thereof is omitted. Processing of S234 to S240 is similar to processing of S201 to S207 in <FIG>, and thus a description thereof is omitted. As such, the determination processing of <FIG> and the determination processing of <FIG> are practically the same, except that the order of determination of the second transfer mode and the third transfer mode is reversed.

Next, with reference to <FIG>, a description is given of determination processing for a case where the combination of "high-speed determination" and "determination with priority on the third transfer mode" has been selected as the determination mode. The system control unit <NUM> executes the overall control on the determination processing of <FIG> in line with a control program stored in the ROM (not shown), unless specifically stated otherwise. Processing of the flowchart of <FIG> is started when the system control unit <NUM> detects that the external recording device <NUM> has been connected to the external recording device connector <NUM>.

Processing of S241 is similar to processing of S214 in <FIG>, and thus a description thereof is omitted. Processing of S242 to S246 is similar to processing of S221 to S225 in <FIG>, and thus a description thereof is omitted. Processing of S247 to S252 is similar to processing of S215 to S220 in <FIG>, and thus a description thereof is omitted. Processing of S253 is similar to processing of S226 in <FIG>, and thus a description thereof is omitted. As such, the determination processing of <FIG> and the determination processing of <FIG> are practically the same, except that the order of determination of the second transfer mode and the third transfer mode is reversed.

As described above, according to the first embodiment, the determination processing shown in any of <FIG> makes it possible to appropriately determine with which standard the external recording device <NUM> is compatible among the plurality of standards.

A second embodiment will be described in relation to a configuration that reduces the time period required for processing in which the communication apparatus determines the transfer mode with which the external recording device <NUM> is compatible. In the second embodiment, the fundamental configuration of the communication apparatus is similar to that of the first embodiment (see <FIG>). The following mainly describes the differences from the first embodiment.

<FIG> are flowcharts of processing in which the communication apparatus determines the transfer mode with which the external recording device <NUM> is compatible in the second embodiment.

<FIG> and <FIG> are flowcharts of determination processing for a case where the combination of "normal determination" and "determination with priority on the second transfer mode" has been selected as the determination mode. According to the determination processing of <FIG> and <FIG>, even in a case where the external recording device <NUM> has been determined to be compatible with the second transfer mode, determination of the third transfer mode is further made using a high-speed determination method, unlike the case of the first embodiment (<FIG>). Therefore, in a case where the external recording device <NUM> is compatible with both of the second transfer mode and the third transfer mode, the communication apparatus can select the third transfer mode, which is higher in speed than the second transfer mode, as the transfer mode to be used within a relatively short determination time period.

<FIG> is a flowchart of determination processing for a case where the combination of "high-speed determination" and "determination with priority on the second transfer mode" has been selected as the determination mode. According to the determination processing of <FIG>, the third transfer mode power source is supplied in parallel with the output of the second transfer mode determination signal. Regarding the determination of the input of the second transfer mode compatibility signal and the determination of the input of the third transfer mode compatibility signal, the former is performed first. Therefore, the determination processing of <FIG> is similar to the determination processing of <FIG> in that the second transfer mode is prioritized over the third transfer mode, but requires a shorter time period in the determination of the third transfer mode after it is determined that the external recording device <NUM> is not compatible with the second transfer mode.

<FIG> is a flowchart of determination processing for a case where the combination of "high-speed determination" and "determination with priority on the third transfer mode" has been selected as the determination mode. According to the determination processing of <FIG>, the third transfer mode power source is supplied in parallel with the output of the second transfer mode determination signal. Regarding the determination of the input of the second transfer mode compatibility signal and the determination of the input of the third transfer mode compatibility signal, the latter is performed first. Therefore, the determination processing of <FIG> is similar to the determination processing of <FIG> in that the third transfer mode is prioritized over the second transfer mode, but requires a shorter time period in the determination of the second transfer mode after it is determined that the external recording device <NUM> is not compatible with the third transfer mode.

First, with reference to <FIG> and <FIG>, a description is given of determination processing for a case where the combination of "normal determination" and "determination with priority on the second transfer mode" has been selected as the determination mode. The system control unit <NUM> executes the overall control on the determination processing of <FIG> and <FIG> in line with a control program stored in the ROM (not shown), unless specifically stated otherwise. Processing of the flowcharts of <FIG> and <FIG> is started when the system control unit <NUM> detects that the external recording device <NUM> has been connected to the external recording device connector <NUM>.

Processing of S300 to S305 is similar to processing of S200 to S205 in <FIG>, and thus a description thereof is omitted.

In S306, the second recording control unit <NUM> issues a third transfer mode determination command from the second physical layer. In the second transfer mode, the second recording control unit <NUM> can transmit a command that is the same as the command in the first transfer mode that has been described with reference to S208 of <FIG>. Also, the transfer speed of the second transfer mode is higher than that of the first transfer mode. Therefore, in the case of the external recording device <NUM> that has been determined to be compatible with the second transfer mode and has a possibility of being compatible with the third transfer mode, the time period required for the determination of the third transfer mode is reduced by issuing the third transfer mode determination command in the second transfer mode.

In S307, the second recording control unit <NUM> determines whether the external recording device <NUM> is compatible with the third transfer mode based on a third transfer mode determination response. In a case where the external recording device <NUM> is compatible with the third transfer mode, processing proceeds to S309; otherwise, processing proceeds to S308.

In a case where the second transfer mode conforms to the UHS-II standard and the third transfer mode conforms to the SDExpress standard, the third transfer mode determination command is CMD8. Also, the third transfer mode determination response is a response to CMD8, and includes information indicating whether the external recording device <NUM> is compatible with the third transfer mode. In this way, the execution of the second initialization processing enables communication in the second transfer mode, and determination of the third transfer mode is made based on communication of the command and the response. It takes approximately several tens of ms from the start of the initialization in the second transfer mode (the UHS-II standard) to the issuance of CMD8.

In S308, the second recording control unit <NUM> continues initialization in the second transfer mode. Note that as stated earlier, the second initialization processing, which is necessary for the second recording control unit <NUM> to perform communication in the second transfer mode, was already executed at the time of S306. Therefore, the continuation of initialization in S308 refers to processing that is different from the second initialization processing.

Processing of S309 is similar to processing of S206 in <FIG>, and thus a description thereof is omitted. Processing of S310 to S317 is similar to processing of S206 to S213 in <FIG>, and thus a description thereof is omitted.

Processing of S318 to S319 and S321 to S322 is similar to processing of S214 to S218 in <FIG> (S200 to S204 in <FIG>), and thus a description thereof is omitted. Processing of S320 is similar to processing of S322 in <FIG>, and thus a description thereof is omitted.

Processing of S324 is similar to processing of S225 in <FIG>, and thus a description thereof is omitted. Processing of S325 is similar to processing of S219 in <FIG>, and thus a description thereof is omitted. Processing of S326 to S331 is similar to processing of S220 to <NUM> and S223 to S226 in <FIG>, and thus a description thereof is omitted.

In <FIG>, the execution of processing of S320 and processing of S321 and S322 is carried out in no particular order. In other words, in <FIG>, processing that serves as the trigger for determination of the third transfer mode and processing that serves as the trigger for determination of the second transfer mode are executed in parallel (substantially at the same time).

Here, it is assumed that the time period from when the third transfer mode power source is supplied to the external recording device <NUM> to when the third transfer mode compatibility signal is input is <NUM> at the longest. Also, it is assumed that the time period from when the second transfer mode determination signal is output from the second physical layer to when the second transfer mode compatibility signal is input is <NUM> at the longest. In this case, according to <FIG> in which the determinations of the second transfer mode and the third transfer mode are made in series, it takes up to <NUM> until the determinations of both of the second transfer mode and the third transfer mode are completed. According to <FIG> in which these determinations are made in parallel, the time period until the determinations of both of the second transfer mode and the third transfer mode are completed is reduced to up to <NUM>.

The reduction of the determination time period will be described more specifically. In S323, the second recording control unit <NUM> determines whether the second transfer mode compatibility signal has been input from the external recording device <NUM> before the elapse of a predetermined time period (a first time period) since the second transfer mode determination signal was output. Also, in S328, the third recording control unit <NUM> determines whether the third transfer mode compatibility signal has been input from the external recording device <NUM> before the elapse of a predetermined time period (a second time period) since the third transfer mode power source was supplied. As such, processing of S323 and S328 per se is similar to S218 and S223 of <FIG>. However, unlike S218 of <FIG>, the supply of the third transfer mode power source has already started at the time of S323 of <FIG>. Therefore, while the second recording control unit <NUM> is waiting for the elapse of the predetermined time period (the first time period) for the determination of S323 in <FIG>, the predetermined time period (the second time period) necessary for the determination of S328 elapses partially or entirely. Thus, the time period required for the determinations of both of the second transfer mode and the third transfer mode, is reduced from the sum of the time periods that are required for the respective determinations to the longer one of the time periods that are required for the respective determinations.

Processing of S332 to S336 is similar to processing of S318 to S332 in <FIG>, and thus a description thereof is omitted. In S337 that follows S336, determination of third transfer mode is made prior to the second transfer mode, unlike <FIG>. Specific processing here is similar to processing of S328 in <FIG>, and thus a description thereof is omitted. In a case where the external recording device <NUM> is compatible with the third transfer mode, processing proceeds to S338; otherwise, processing proceeds to S341.

Processing of S338 to S340 is similar to processing of S326 to S327 and S329 in <FIG>, and thus a description thereof is omitted.

Processing of S341 is similar to processing of S330 in <FIG>, and thus a description thereof is omitted. Thereafter, the determination of the second transfer mode is made in S342. That is to say, unlike <FIG>, the determination of the second transfer mode is made after the determination of the third transfer mode. Specific processing here is similar to processing of S323 in <FIG>, and thus a description thereof is omitted. In a case where the external recording device <NUM> is compatible with the second transfer mode, processing proceeds to S343; otherwise, processing proceeds to S344.

Processing of S343 to S345 is similar to processing of S325, S326, and S331 in <FIG>, and thus a description thereof is omitted.

Here, it is assumed that the time period from when the third transfer mode power source is supplied to the external recording device <NUM> to when the third transfer mode compatibility signal is input is <NUM> at the longest. Also, it is assumed that the time period from when the second transfer mode determination signal is output from the second physical layer to when the second transfer mode compatibility signal is input is <NUM> at the longest. In this case, according to <FIG> in which the determinations of the second transfer mode and the third transfer mode are made in series, it takes up to <NUM> until the determinations of both of the second transfer mode and the third transfer mode are completed. According to <FIG> in which these determinations are made in parallel, the time period until the determinations of both of the second transfer mode and the third transfer mode are completed is reduced to up to <NUM>, similarly to <FIG>. That is to say, similarly to the case of <FIG>, the time period required for the determinations of both of the second transfer mode and the third transfer mode, is reduced from the sum of the time periods that are required for the respective determinations to the longer one of the time periods that are required for the respective determinations.

As described above, according to the second embodiment, the determination processing shown in any of <FIG> and <FIG> makes it possible to determine with which standard the external recording device <NUM> is compatible among the plurality of standards in a short time period compared to the first embodiment.

The present invention can be implemented by processing of supplying a program for implementing one or more functions of the above-described embodiments to a system or apparatus via a network or storage medium, and causing one or more processors in the computer of the system or apparatus to read out and execute the program. The present invention can also be implemented by a circuit (for example, an ASIC) for implementing one or more functions.

This application claims priority from <CIT>.

Claim 1:
A communication apparatus, comprising:
a connection unit (<NUM>) that includes a plurality of signal lines and is configured to connect to an external recording device (<NUM>); and
control means (<NUM>) for controlling communication with the external recording device (<NUM>) connected to the connection unit (<NUM>),
wherein
the control means (<NUM>) is configured to perform control to:
determine whether a second signal has been input before a predetermined time period elapses since a first signal was output to the external recording device (<NUM>), the second signal indicating that the external recording device (<NUM>) is compatible with a second transfer mode;
in a case where it is determined that the second signal has been input, perform communication in the second transfer mode; and
in a case where it is determined that the second signal has not been input,
start first initialization processing for performing communication in a first transfer mode,
determine whether the external recording device (<NUM>) is compatible with a third transfer mode based on communication in the first transfer mode, and
in a case where it is determined that the external recording device (<NUM>) is compatible with the third transfer mode, perform communication in the third transfer mode.