JP4692122B2 - Interface device and printing apparatus having the same - Google Patents

Description

  The present invention relates to an interface apparatus for exchanging data between a host apparatus and a device apparatus, and an improvement of a printing apparatus including the interface apparatus.

  In today's integrated circuits (LSIs), the miniaturization of transistors, which are their structural units, has progressed, and as a result, leakage current flows despite no switching operation. Therefore, energy saving and power saving of electrical equipment using integrated circuits are achieved. The need for is urgently needed. The same applies to the interface device for exchanging data between the host device and the device device.

  Conventionally, power has been saved by a method of stopping the operation of a part or the whole of the integrated circuit, a method of stopping the clock supply, a method of reducing the clock operating frequency, etc., but leakage current due to miniaturization of the integrated circuit Due to the increase in power consumption, a sufficient power saving effect cannot be obtained only by stopping the operation of the integrated circuit. For this reason, in recent years, a method of stopping the power supply itself to the integrated circuit has been adopted. In this case, since the power supply to the integrated circuit is stopped, there is a possibility that the response when data transmission or data request from an external device is delayed is delayed and the operation cannot be resumed properly.

    Therefore, for example, in Patent Document 1 below, when there is data transmission from the host computer in the power saving mode in which the power supply from the main power supply is stopped, the response control unit communicates with the host computer according to the communication control information, A printing apparatus that returns to the normal transfer mode during this time is disclosed.

Patent Document 2 below discloses a power supply circuit and a communication system that supply power only to a function for returning to a normal operation state in a power saving mode.
Japanese Patent Application Laid-Open No. 2002-244834 JP 2003-228444 A

  However, in the conventional technique described in Patent Document 1, since power is supplied to the entire interface portion related to data reception, the problem of increased leakage current cannot be dealt with.

  In the conventional technique described in Patent Document 2, since power is not supplied to a part other than the function for returning to the normal operation state in the power saving mode, for example, the interface unit or the like, the power is not supplied to the host computer. However, there is a problem that it is necessary to configure the host computer side so that it does not time out before the main power is supplied and the system returns from the power saving mode.

  SUMMARY An advantage of some aspects of the invention is that it provides an interface device that improves both power saving and responsiveness to an external device, and a printing apparatus including the interface device.

  To achieve the above object, the present invention provides an interface device for exchanging data between a host device and a device device, and a data transfer process for processing data transfer between the host device and the device device. Means, power supply stopping means for stopping power supply from the main power supply for supplying power to the interface device in the power saving mode, and receiving power supply from the sub power supply and transmitting data from the host device in the power saving mode. Alternatively, when there is a data request, the power saving operation processing means for sending data for requesting re-execution to the host device, and in the power saving mode, the power is supplied from the secondary power source and the data is transmitted from the host device. Or when there is a data request, the power supply restarting means restarts the power supply stopped by the power supply stop means. Characterized in that it comprises a stage, a.

  Further, the power saving operation processing means stops the operation when the operation of the interface device returns to a normal state by resuming the power supply by the power supply resuming means.

  Further, in the interface device, the data transfer processing means is a universal serial bus transfer buffer, and the power saving operation processing means includes a communication means for receiving a setup transaction, an out transaction, and an in transaction from a host device; And access control means for returning data requesting re-execution of out-transaction or in-transaction to the host device.

  The power saving operation processing means includes setup transaction holding means for holding a setup transaction when the communication means receives the setup transaction.

  The communication means and the access control means may be supplied with power from a sub power source different from the main power source of the interface device.

  In addition, the present invention is a printing apparatus including any one of the interface devices described above.

  According to the present invention, in the power saving mode, the power stop means stops the power supply from the main power supply, the power saving operation processing means receives the power supply from the sub power supply, and there is a data transmission or data request from the host device. In this case, since data for requesting re-execution is sent to the host device, both power saving and responsiveness to the external device can be improved.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings.

  FIG. 1 shows a block diagram of a configuration example of an interface device according to the present invention. In FIG. 1, the device device 10 includes an interface device 14 for exchanging data with the host device 12. Here, examples of the device device 10 include a printing apparatus. Examples of the host device 12 include a host computer.

  The interface device 14 includes a communication unit 16, a data transfer processing unit 18, a power saving operation processing unit 20, a power supply control unit 22, and a storage unit 24.

  The communication unit 16 receives data transmitted from the host device 12 and performs an operation of transmitting the requested data to the host device 12 when a data request is received from the host device 12. The communication unit 16 is configured to receive power supply from the sub power supply 26 even in the power saving mode.

  The data transfer processing unit 18 processes data transfer between the host device 12 and the device device 10. For example, the data received by the communication unit 16 from the host device 12 is temporarily stored in a buffer and transferred to the device device 10, or the data requested from the host device 12 is received from the device device 10 and temporarily stored in the buffer. Then, an operation such as passing this to the communication unit 16 is performed. The buffer may be formed in the storage unit 24.

  In the power saving mode, the power saving operation processing unit 20 transmits data or data to the host device 12 via the communication unit 16 when data is transmitted from the host device 12 via the communication unit 16 or when a data request is received. An operation of sending data for requesting re-execution of the request is performed. Here, as data for requesting the re-execution, for example, when a universal serial bus (USB) is used, a NAK response corresponds to this. The power saving operation processing unit 20 is configured to receive power supply from the sub power source 26 even in the power saving mode.

  The power supply control unit 22 stops when there is an operation to stop the power supply from the main power supply 28 that supplies power to the interface device 14 in the power saving mode, and when there is a data transmission or data request from the host device 12 in the power saving mode. The power supply to the interface device 14 in the power saving mode and the normal operation mode is controlled. The power supply control unit 22 is configured to receive power supply from the sub power supply 26 even in the power saving mode.

  The storage unit 24 includes, for example, a working RAM of the CPU, a flash memory as a non-volatile memory, a magnetic storage device, and the like, such as whether the interface device 14 is in a power saving mode or a normal operation mode. Store data and programs.

  FIG. 2 shows a flowchart of an example of the power saving operation of the interface device 14. In FIG. 2, when the interface device 14 starts the power saving mode (S1), the power supply control unit 22 stops the power supply from the main power supply 28 to the interface device 14 (S2). The power supply control unit 22 in this case functions as a power supply stop unit according to the present invention. Even in this case, power is supplied to the communication unit 16, the power saving operation processing unit 20, and the power supply control unit 22 from the sub power supply 26.

  Next, the communication unit 16 monitors the access including the data transmission or data request from the host device 12 (S3), and if there is an access from the host device 12, the communication unit 16 notifies the power saving operation processing unit 20 to that effect. To be notified.

  When the notification is received from the communication unit 16, the power saving operation processing unit 20 transmits data for requesting data transmission or re-execution of the data request to the host device 12 via the communication unit 16 ( S4). Thereby, the time for returning from the power saving mode to the normal operation mode can be secured. The power saving operation processing unit 20 instructs the power supply control unit 22 to stop the power saving mode, and the power supply control unit 22 resumes the power supply stopped in S2 (S5). The power supply control unit 22 in this case functions as power supply restarting means according to the present invention.

  Next, the power saving operation processing unit 20 monitors whether the data transfer processing unit 18 and other circuits of the interface device 14 for which power supply has been resumed have started normal operation (S6). When the normal operation is started, the power saving mode of the power saving operation processing unit 20 ends. That is, when the communication unit 16 is accessed from the host device 12, the power saving operation processing unit 20 does not transmit data for requesting data transmission or re-execution of the data request (S7). Note that when the power saving mode ends, the power supply from the sub power supply 26 to the communication unit 16, the power saving operation processing unit 20, and the power supply control unit 22 may be stopped, and the power supply may be received from the main power supply 28. .

  FIG. 3 is a block diagram showing an example in which the interface device 14 shown in FIG. 1 is realized by USB (Universal Serial Bus). In FIG. 3, an LSI 30 having a USB device function is provided with a USB device unit 32 that functions as a USB interface. The USB device unit 32 is provided with the communication unit 16 shown in FIG. 1 and an SIE (serial interface engine) 34. Here, the communication unit 16 is configured as a device that performs high-speed serial communication with the host device 12. The SIE 34 has a function of exchanging data with the host device 12 while controlling the communication unit 16 and a function of executing the power saving operation described above in the power saving mode. That is, the SIE 34 includes a buffer unit 36 corresponding to the data transfer processing unit 18 shown in FIG. 1, an access control unit 38 corresponding to the power saving operation processing unit 20, and a main power control unit 40 corresponding to the power control unit 22. I have.

  The buffer unit 36 includes a control transfer buffer I for a setup transaction, a control transfer buffer II, a transfer buffer I for an out transaction, and a transfer buffer II for an in transaction according to USB specifications. . However, the control transfer buffer II is supplied with power from the sub power source 26 together with the access control unit 38 and the main power source control unit 40, and constitutes a power saving USB module 41. The control transfer buffer II is a buffer for storing the contents when a setup transaction is transmitted from the host device 12 during the power saving mode. Further, a plurality of transfer buffers I and transfer buffers II may be provided in order to improve transfer efficiency.

  Each of the above units is operated while exchanging data with a CPU (Central Processing Unit) 42 and a bus 44. The memory 46 is a component of the storage unit 24 shown in FIG. 1 and provides the CPU 42 with a memory area for operation.

  FIG. 4 shows a detailed block diagram of the configuration of the SIE 34 shown in FIG. In FIG. 4, the access control unit 38 includes a token phase recognition unit 48, a data phase input unit 50, a data phase output unit 52, a handshake phase recognition unit 54, and a handshake phase output unit 56. Regardless of the presence or absence of the power saving function provided by, this is a necessary component for exchanging data with the host device 12.

  The access control unit 38 is also provided with a state holding unit 58, which holds the state of whether the interface device 14 is in the power saving mode or the normal operation mode. This state holding unit 58 is a component of the storage unit 24 shown in FIG.

  The data transmitted from the host device 12 is recognized by the token phase recognition unit 48 via the communication unit 16, whereby the data phase input unit 50, the data phase output unit 52, the handshake phase recognition unit 54, and the handshake phase output. The power saving USB module 41 including the unit 56 performs the operations described below.

  First, the data transmitted from the host device 12 includes a setup transaction shown in FIG. 5, an out transaction shown in FIG. 6, and an in transaction shown in FIG.

  The setup transaction shown in FIG. 5 is used for control transfer. Control transfer is mainly used when the host device 12 transmits configuration data to the device device 10 or acquires configuration information of the device device 10. The control transfer is composed of three stages, a setup stage, a data stage, and a status stage, and there are three types of control transfers depending on the data stage and the subsequent status stage.

  The setup stage (setup transaction) includes a token phase including information indicating a transaction type, a data phase including information for instructing the CPU 42 to perform an operation, and a handshake including information for reporting a communication result in the setup stage. Consists of phases. However, the handshake phase of the setup stage has a specification that an ACK response packet indicating communication success must be returned to the host device 12 without fail. For this reason, when a setup transaction is received in the power saving mode, it is not permitted to return a NAK response to the host device 12 and request re-execution. Therefore, in the power saving USB module 41 according to the present embodiment, a data packet sent from the host device 12 in the setup stage is supplied with power from the secondary power source 26 even in the power saving mode, and can be operated. The CPU 42 is configured to determine how the CPU 42 should operate when returning to the normal operation mode. Here, the control transfer buffer II corresponds to the setup transaction holding means according to the present invention.

  The out transaction shown in FIG. 6 is used for bulk-out transfer. The bulk-out transfer is used when data is transmitted from the host device 12 to the device device 10 and includes a series of out transactions. The out transaction includes a token phase including information indicating the type of transaction, a data phase including data to be transmitted to the device apparatus 10, and a handshake phase including information for reporting a communication result in the data phase.

  When the device device 10 can receive the data transmitted from the host device 12 in the data phase, an ACK response packet indicating the fact is received. When the device device 10 cannot receive the data, a NAK response packet indicating the fact is received as the handshake phase. To the host device 12. When receiving the NAK response packet, the host device 12 re-executes the out transaction in response to this. As described above, the NAK response corresponds to data for requesting the host device 12 according to the present invention to re-execute. Note that the STALL response returned to the host device 12 in the handshake phase means that the device device 10 is inoperable.

  The in-transaction shown in FIG. 7 is used for bulk-in transfer. The bulk-in transfer is used when the host device 12 requests data from the device device 10 and includes a series of in-transactions. The in-transaction includes a token phase including information indicating a transaction type, a data phase including data to be transmitted to the host device 12, and a handshake phase including information for reporting a communication result in the data phase.

  When the host device 12 can receive the data transmitted from the device device 10 in the data phase, the ACK response packet indicating that is received. When the host device 12 is not able to receive the data, the NAK response packet indicating that is received in the handshake phase. To return to the device 10.

  In addition, when the device device 10 has not prepared data to be sent back to the host device 12 in the data phase, a NAK response packet indicating the fact is displayed. When the device device 10 is not operable, a STALL response packet indicating the fact is displayed. Is returned to the host device 12 in the handshake phase. When receiving the NAK response packet, the host device 12 re-executes the in-transaction in response to this. Also in this case, the NAK response corresponds to data for requesting the host device 12 according to the present invention to re-execute.

  Next, the operation of the power saving USB module 41 will be described. For example, when a setup transaction is sent from the host device 12, when the token phase recognition unit 48 recognizes a setup packet that is the first (token phase) packet of the setup transaction, it is sent from the host device 12 in the next data phase. The data phase input unit 50 stores the incoming data packet in the control transfer buffer II. The handshake phase output unit 56 returns an ACK response packet to the host device 12.

  In addition, when an out transaction is sent from the host device 12, when the token phase recognition unit 48 recognizes an out packet that is the first (token phase) packet of the out transaction, in the next data phase, the data packet is transmitted from the host device 12. Will be sent. Thus, the next packet is received by the data phase input unit 50 and stored in the transfer buffer I. When the packet can be stored in the transfer buffer I, the handshake phase output unit 56 returns an ACK response packet to the host device 12, and when the storage fails, the handshake phase output unit 56 returns to the host device 12. A NAK response packet is returned to prompt retransmission of the data packet.

  When an in-transaction is sent from the host device 12, the token phase recognition unit 48 recognizes the in-packet that is the first packet (token phase) of the in-transaction, and is data ready to be returned to the host device 12 ready? The data phase output unit 52 determines whether or not. When data can be returned, the data phase output unit 52 outputs a data packet. If the data is not ready, the handshake phase output unit 56 returns a NAK response to the host device 12 to prompt retransmission of the in-transaction. After a data packet is sent from the data phase output unit 52 to the host device 12, if a NAK response is sent from the host device 12, the handshake phase recognition unit 54 recognizes this NAK response, and the host device 12 receives the data. Judge that reception failed. In this case, when an in-transaction is sent again from the host device 12, the data phase output unit 52 resends the data packet sent last time.

  Here, in order to set the SIE 34 according to the present embodiment to the power saving mode, when a message indicating that the power saving state is written in the state holding unit 58, if a transaction other than the setup transaction is sent from the host device 12, the token phase After the recognition unit 48 recognizes the token phase, the NAK response packet is always returned from the handshake phase output unit 56 to the host device 12 in the next phase.

  When a setup transaction is sent, the same processing as in the normal mode is performed, and the processing in the power saving mode is performed from the transaction sent after the setup transaction. That is, the NAK response packet is returned from the handshake phase output unit 56 to the host device 12.

    At this time, the main power supply control unit 40 stops the power supply from the main power supply 28. The main power supply control unit 40 in this case functions as a power supply stop unit according to the present invention. Thereby, the power supply to circuits other than the communication unit 16 and the power saving USB module 41 is stopped, and the power saving mode is set.

  Next, when the token phase recognition unit 48 recognizes that data such as a setup transaction has been transmitted from the host device 12, the NAK response packet is returned from the handshake phase output unit 56 to the host device 12, and the main power control is performed. The unit 40 resumes power supply from the main power supply 28. The main power supply control unit 40 in this case functions as power supply restarting means according to the present invention.

    Here, after the operation of the circuit that provides a function sufficient to exchange data between the device device 10 and the host device 12 returns to the normal state, the CPU 42 is in the normal operation state in the state holding unit 58. Write a notice. When the power saving return trigger is a setup transaction, the CPU 42 reads the control transfer buffer II before the write processing to the state holding unit 58.

  With the above configuration, in the power saving mode, power is supplied from the auxiliary power supply 26 only to the communication unit 16 and the power saving USB module 41 to save power, and the communication unit 16 and the power saving USB module 41 also operate in the power saving mode. Therefore, a decrease in responsiveness to external devices can be avoided.

  FIG. 8 is a block diagram showing another example in which the interface device 14 shown in FIG. 1 is realized by USB, and the same elements as those in FIG. 3 are denoted by the same reference numerals. A characteristic point in FIG. 8 is that the power saving USB module 41 is formed outside the SIE 34. As a result, the interface device 14 of the present invention can be realized even for a model having a specification in which the power saving USB module 41 cannot be formed in the SIE 34.

It is a block diagram of the structural example of the interface apparatus concerning this invention. It is a flowchart of the example of the power saving operation | movement of the interface apparatus concerning this invention. It is a block diagram which shows the example which implement | achieved the interface apparatus concerning this invention by USB. FIG. 4 is a detailed block diagram of the configuration of the SIE shown in FIG. 3. It is a figure which shows a setup transaction. It is a figure which shows an out transaction. It is a figure which shows an in transaction. It is a block diagram which shows the other example which implement | achieved the interface apparatus concerning this invention by USB.

Explanation of symbols

  10 device device, 12 host device, 14 interface device, 16 communication unit, 18 data transfer processing unit, 20 power saving operation processing unit, 22 power control unit, 24 storage unit, 26 sub power supply, 28 main power supply, 30 LSI, 32 USB Device section, 34 SIE, 36 buffer section, 38 access control section, 40 main power supply control section, 41 power saving USB module, 42 CPU, 44 bus, 46 memory, 48 token phase recognition section, 50 data phase input section, 52 data phase An output unit, a 54 handshake phase recognition unit, a 56 handshake phase output unit, and a 58 state holding unit.

Claims (3)

An interface device for exchanging data between a host device and a device device,
A data transfer processing means, which is a universal serial bus transfer buffer, for processing data transfer between the host device and the device device;
Power supply stopping means for stopping power supply from the main power supply for supplying power to the interface device in the power saving mode;
In the power saving mode, the power supply is received from the secondary power supply, and the setup transaction, the out transaction and the in transaction are received from the host device. A power saving operation processing means for returning to the host device ;
A setup transaction holding means for holding a data packet for instructing an operation when the power saving mode ends, included in the power saving operation processing means when receiving the setup transaction ;
Power supply restarting means for receiving power supply from the sub power supply in the power saving mode and restarting the power supply stopped by the power supply stop means when receiving a setup transaction, an out transaction and an in transaction from the host device; ,
Equipped with a,
Rukoto the power saving mode, the resumption of the power supply by the power supply resuming means, the operation of the interface device is finished when waking successfully, the power-saving operation processing means, to stop operation and the power-saving mode ends An interface device. 2. The interface device according to claim 1, wherein the communication unit and the access control unit are supplied with power from a sub power source different from a main power source of the interface device. A printing apparatus comprising the interface device according to claim 1.

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