JP2011154549A - Universal serial bus host device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a USB host device and a program for allowing a USB host device to recognize a USB device with a simpler configuration. <P>SOLUTION: When an abnormal recognition signal (USB+, USB-) is detected by a USB host controller 24n as a recognition signal detection part, and supply of power (VCC) is interrupted, a CPU 24a as a switching control part resumes the supply of power (VCC). A POS terminal 22 as a host device for a plurality of USB devices 26 is provided with a restoration mechanism, so that it is simpler than when each of the USB devices 26 is provided with the restoration mechanism. Therefore, cost reduction is achieved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a universal serial bus host device and a program.

  Conventionally, in a system in which a universal serial bus (hereinafter referred to as USB) device is connected to a USB host device, if the USB host device cannot recognize the USB device due to some abnormality, a connector can be connected or disconnected. There is known a system that can recover the recognition of a USB device by a USB host device without restarting (for example, Patent Document 1).

  However, in Patent Document 1, a recovery mechanism for recovering recognition of a USB device is equipped in the USB device. For this reason, in a system in which a plurality of USB devices are connected to a USB host device, such as a POS (Point Of Sales) system, the above-described recovery mechanism is provided in each of the plurality of USB devices, resulting in a complicated system configuration. And there is a risk that the cost may increase.

  SUMMARY An advantage of some aspects of the invention is that it provides a USB host device and a program capable of recovering recognition of a USB device by the USB host device with a simpler configuration.

  The present invention includes a recognition signal detection unit that detects a recognition signal from a connected universal serial bus device, and a switching control unit that switches between supply and cut-off of power to the connected universal serial bus device, The switching control unit restarts the power supply when the recognition signal abnormality is detected by the recognition signal detection unit and the power supply is cut off.

  According to the present invention, it is possible to obtain a USB host device and program capable of recovering recognition of a USB device by the USB host device with a simpler configuration.

FIG. 1 is a diagram showing a schematic configuration of a commodity sales system as an information processing system according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of a POS terminal as a USB host device. FIG. 3 is a diagram showing a schematic configuration of the CPU of the POS terminal. FIG. 4 is a schematic configuration diagram showing a POS terminal and a part of the POS terminal. FIG. 5 is a diagram showing the waveform of the signal in each part of FIG.

  Hereinafter, an embodiment of an information processing system according to the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a product sales system 1 as an information processing system according to the present embodiment includes a store system 2. The store system 2 is connected to another device (for example, a POS (Point Of Sales) headquarters system (not shown)) via a telecommunication line 4 such as a public network or the Internet VPN (Virtual Private Network). Yes.

  The store system 2 includes a store server 21 as a computer that plays a central role in the system, and a POS terminal 22 as a product sales terminal device. The store server 21 and the POS terminal 22 are connected via a telecommunication line 23 such as a LAN (Local Area Network).

  As shown in FIG. 2, a POS terminal 22 as a USB host device includes a CPU (Central Processing Unit) 24a, a ROM (Read Only Memory) 24b, a RAM (Random Access Memory) 24c, a clock unit 24d, and an I / O (Input / Output). / Output) port 24e, network interface 24f, keyboard controller 24g, touch panel controller 24h, display controller 24i, printer controller 24j, scanner controller 24k, hard disk (HDD) controller 24m, and USB host controller 24n. As shown in FIG. 2, they are connected via a bus line 24p such as an address bus or a data bus.

  The CPU 24a controls the POS terminal 22 by executing various computer-readable programs stored in the ROM 24b. The ROM 24b stores various programs (application program, device driver program, etc.) and various data executed by the CPU 24a. The RAM 24c temporarily stores data and programs when the CPU 24a executes various programs. In the present embodiment, the program for the POS terminal 22 includes a module for performing sales registration, a module for performing electronic settlement, a module for performing communication control, a module for controlling switching of power supply to the USB device, and a USB device. A module for variably setting a time interval for restarting after the power supply is cut off is included. Therefore, according to this program, the CPU 24a of the POS terminal 22 operates as a sales registration unit 41, an electronic settlement unit 42, a communication control unit 43, a switching control unit 44, a time setting control unit 45, etc., as shown in FIG. To do.

  Further, the clock unit 24d shown in FIG. 2 measures the current date and time. The network interface 24f controls data communication with other devices connected through the telecommunication lines 23, 4 and the like. The I / O port 24e inputs a mode selection signal from the mode switch 25a and outputs a drive signal to a drawer opening device 25b that automatically opens a drawer (not shown). The keyboard controller 24g captures a key signal corresponding to the operation key from the keyboard 25c and notifies the CPU 24a of the key signal. The touch panel controller 24h controls the customer display 25e with a touch panel to display characters corresponding to the display data supplied from the CPU 24a in color, and receives signals from the touch panel sensor 25d attached to the screen of the display 25e. And notifies the CPU 24a. The display controller 24i controls the operator display 25f to display characters corresponding to the display data provided from the CPU 24a in color. The printer controller 24j controls the driving of the R / J printer 25g to perform receipt printing and journal printing based on print data supplied from the CPU 24a. The scanner controller 24k takes in a signal of data read by the scanner 25h and sends it to the CPU 24a.

  The hard disk controller 24m controls writing and reading of data to and from the hard disk 25i based on an instruction signal from the CPU 24a. The hard disk 25i has a storage area for data related to the system, as well as data indicating a restart time for restarting after the power supply to the USB device 26 is shut off.

  Further, the USB host controller 24n receives the instruction signal from the CPU 24a and controls the USB device (USB device) 26. Specifically, the communication between the CPU 24 a and the USB device 26, that is, the exchange of data between the CPU 24 a and the USB device 26 is controlled.

  Here, with reference to FIGS. 4 and 5, USB communication in the POS terminal 22 and the USB device 26 according to the present embodiment will be described in more detail.

  As shown in FIG. 4, the POS terminal 22 includes a CPU 24a and a USB host controller 24n, a constant voltage power supply 28 as a power supply, a power supply switching circuit 29, and the like as parts related to USB communication. The USB device 26 is connected to the POS terminal 22 via connectors 27f and 27m (27).

  Power is supplied from the constant voltage power supply 28 to the USB device 26 via the power supply switching circuit 29 and the connector 27. The power supply switching circuit 29 includes a switch 29a. Switching on and off of the switch 29a can be controlled by a switching control signal (CTRL) from the CPU 24a that operates as the switching control unit 44 (see FIG. 3). Note that the switching control signal (CTRL) from the CPU 24a can be supplied to the power supply switching circuit 29 via a circuit (not shown) such as a controller, for example. In the present embodiment, as shown in FIG. 5, when the switching control signal (CTRL) is at a high level (H), the potential (VCC) of the power supply line is at a high level (H) and power is supplied. . In the present embodiment, the ground lines of the POS terminal 22 and the USB device 26 are connected through the connector 27, and the ground potential (GND) is common.

  In addition, the USB device 26 to which power is supplied has a circuit that generates a recognition signal (USB +, USB−). As shown in FIG. 5, the recognition signals (USB +, USB−) are a pair of signals having opposite phases to each other, and in either signal, the high level (H) and the low level (L) have a constant cycle. It repeats alternately at T. That is, when the recognition signal USB + is at a high level (H), the other recognition signal USB− that makes a pair is at a low level (L), and conversely, when the recognition signal USB + is at a low level (L). The other recognition signal USB- that makes a pair is at a high level (H). The USB device 26 includes, for example, a pull-up power source (not shown) and a ground, and is connected by alternately connecting a pair of recognition signal (USB +, USB−) lines to the pull-up power source at regular intervals. Recognition signals (USB +, USB-) can be generated.

  In this embodiment, the USB host controller 24n has a function of detecting a recognition signal (USB +, USB−). Specifically, for example, the USB host controller 24n uses a circuit that detects the level of the recognition signal (USB +, USB−), a clock from an internal or external timer circuit (not shown), and the like. It has a circuit for measuring the duration time of the level of (USB +, USB−), a circuit for comparing the duration time and a threshold time Tt (for example, T + δt, δt = allowable time) (both not shown) and the like. If the level of the recognition signal (USB +, USB−) does not change even when the duration time reaches or exceeds the threshold time Tt, the USB host controller 24n detects an abnormality with respect to the CPU 24a. A signal (DET) can be sent. In this case, the CPU 24a operates as the switching control unit 44, and sends a switching control signal (CTRL low level (L)) to the power supply switching circuit 29, as shown in FIG. Turn off. That is, in this embodiment, when an abnormality of the recognition signal (USB +, USB−) is detected, the supply of power from the POS terminal 22 to the USB device 26 is cut off, and the function of the USB device 26 is stopped. Therefore, it is possible to avoid an inconvenient situation in the circuit or the like of the USB device 26 due to the operation of the USB device 26 continuing during an abnormality. In the present embodiment, the USB host controller 24n corresponds to a recognition signal detection unit.

  Further, as shown in FIG. 5, the CPU 24a operating as the switching control unit 44 supplies power when a certain time (Tr: restart time) elapses after the abnormality of the recognition signal (USB +, USB−) is detected. A switching control signal (CTRL high level (H)) is sent to the switching circuit 29, the switch 29a is turned on, and the supply of power from the constant voltage power supply 28 to the USB device 26 is resumed. In the present embodiment, even if some abnormality occurs due to such control and the POS terminal 22 as the USB host device cannot recognize the USB device 26 as the USB device, the power to the USB device 26 is lost. Since the USB device 26 is restarted by restarting the supply of power after the supply of power is interrupted, the USB by the POS terminal 22 is not required without connecting or disconnecting the connector 27 or restarting the POS terminal 22. Recognition of the device 26 can be restored.

  Further, the USB host controller 24n can detect that the USB device 26 is connected to the POS terminal 22. Specifically, whether or not connection is possible can be detected, for example, when one of the paired recognition signals (USB +, USB−) is at a high level (H). Incidentally, when the USB device 26 is not connected to the POS terminal 22, both of the paired recognition signals (USB +, USB−) are at a low level (L). Then, when an abnormality is detected in the recognition signal (USB +, USB−), the USB host controller 24n detects an abnormality detection signal (DET) toward the CPU 24a only when the USB device 26 is connected to the POS terminal 22. Can send. In the present embodiment, such control makes it possible to distinguish between a case where an abnormality occurs in a state where the USB device 26 is connected and a recovery is necessary, and a case where the USB device 26 is removed. In the present embodiment, the USB host controller 24n corresponds to a connection detection unit that detects whether or not the USB device 26 can be connected. The USB host controller 24n may send a connection enable / disable signal to the CPU 24a separately from the abnormality detection signal (DET). In this case, when an abnormality is detected by the USB host controller 24n, an abnormality detection signal (DET) is sent from the USB host controller 24n to the CPU 24a regardless of whether connection is possible. Then, the CPU 24 a operating as the switching control unit 44 determines whether or not to send a switching control signal (CTRL) to the switching control circuit 29.

  In the present embodiment, the restart time Tr can be variably set according to the situation. Specifically, the CPU 24a operates as the time setting control unit 45 (see FIG. 3), and information indicating the resume time Tr stored in the hard disk 25i or the like based on input from the keyboard 25c, the touch panel sensor 25d, or the like. Can be changed. That is, in the present embodiment, it becomes easier to set a more appropriate restart time Tr depending on the state of occurrence of an abnormality, so that recovery can be performed more reliably. Specifically, for example, when an abnormality that takes time to be resolved is likely to occur, the restart time Tr can be set longer.

  Examples of the USB device 26 connected to the POS terminal 22 via the circuit configuration include a barcode scanner, a card reader / writer, and an IC chip reader. The USB device 26 can be used to execute sales registration processing by the sales registration unit 41 (see FIG. 3), electronic payment processing by the electronic payment unit 42 (see FIG. 3), and the like. For example, the sales registration unit 41 detects the product ID from the barcode data of the product read by the barcode scanner (but may be the scanner 25h (see FIG. 2)) as the USB device 26, and corresponds to the product ID. The store server 21 is inquired about price data, sales data of the product is generated based on the received price data, and is stored in a storage unit such as the RAM 24c. Further, the electronic settlement unit 42, for example, calculates sales amounts by collecting sales data, and displays this on the display 25e. Then, the electronic settlement unit 42 makes the POS terminal 22 ready for settlement by the electronic settlement system desired by the customer based on the operation of the operator. Then, the CPU 24a operates a card reader / writer, an IC chip reader / writer, etc. (not shown) corresponding to the electronic payment system desired by the customer, and exchanges data necessary for payment with the card or terminal. Furthermore, it communicates with an external server etc. as needed, and performs a payment process. At this time, the electronic settlement unit 42 holds the electronic settlement ID in a storage unit such as the RAM 24c. The sales registration unit 41 and the electronic settlement unit 42 correspond to an information processing unit.

  As described above, in the present embodiment, the switching control unit 44 detects an abnormality from the specified state of the recognition signal (USB +, USB−) by the USB host controller 24n as the recognition signal detection unit, and the power (VCC) ) Is cut off, the supply of power (VCC) is resumed. Therefore, when the POS terminal 22 as the USB host device cannot recognize the USB device 26 as the USB device due to some abnormality and wants to recover the recognition, the USB device 26 is restarted by restarting the supply of power (VCC). Then, the generation of the recognition signal (USB +, USB−) is restarted. For this reason, the recognition of the USB device 26 by the POS terminal 22 can be restored without removing and inserting the connector 27 or restarting the POS terminal 22. In this embodiment, since the recovery mechanism is provided in the POS terminal 22 as the USB host device for the plurality of USB devices 26, the configuration is simplified as compared with the configuration in which the recovery mechanism is provided in each of the USB devices 26. Can contribute to cost reduction.

  In the present embodiment, the switching control unit 44 detects the power (VCC) to the USB device 26 when the USB host controller 24n as the recognition signal detection unit detects an abnormality in the recognition signal (USB +, USB−). After the supply is cut off, the supply of power (VCC) is resumed. Therefore, according to the present embodiment, it is possible to avoid the occurrence of an unfavorable situation in the circuit of the USB device 26 and the like due to the USB device 26 continuing to operate in the event of an abnormality.

  In this embodiment, the switching control unit 44 is operated by the USB host controller 24n serving as the connection detection unit when an abnormality of the recognition signal (USB +, USB−) is detected by the USB host controller 24n serving as the recognition signal detection unit. When it is detected that the USB device 26 is not connected (that is, when it is not detected that the USB device 26 is connected), the supply of power (VCC) to the USB device 26 is not resumed. . Therefore, in this embodiment, when the USB device 26 is removed from the POS terminal 22, it is possible to suppress the above-described reset control (supply resumption control after power interruption) being performed wastefully. If it is determined by the CPU 24a or the like that the USB device 26 is removed based on the recognition signal detection unit, the switching control unit 44 is necessary (for example, after a time longer than the restart time Tr). As a result, the switch 29a is turned on, and the POS terminal 22 can be brought into a state in which power (VCC) is supplied when the USB device 26 is connected.

  In the present embodiment, the USB host controller 24n as the connection detection unit determines whether the USB device 26 can be connected by either the high level (H) or the low level (L) of the recognition signal (USB +, USB−). Is detected. Therefore, it is possible to detect whether or not the USB device 26 can be connected with higher accuracy by a relatively simple configuration.

  In the present embodiment, the time setting control unit 45 that variably sets the restart time is provided. Therefore, the reset control according to the present invention can be more appropriately performed according to the occurrence state of the abnormality.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various modifications can be made. For example, in the above-described embodiment, the case where the USB host device according to the present invention is configured as the POS terminal 22 is exemplified. However, the USB host device according to the present invention may be used as another information processing apparatus (for example, a personal computer). Can be implemented.

  In the above-described embodiment, the USB host controller 24n is exemplified as the recognition signal detection unit and the connection detection unit. However, the CPU 24a can also operate as the recognition signal detection unit and the connection detection unit. In this case, the program executed by the CPU 24a includes a module that operates as a recognition signal detection unit and a module that operates as a connection detection unit. The USB host controller 24n to the CPU 24a receive a signal ( That is, a signal capable of detecting them is sent. Moreover, you may implement so that the function of a switching control part may be acquired as operation | movement of elements other than CPU24a.

  Further, the recognition signal detection unit can detect not only the comparison of the durations but also other abnormalities that have occurred in the recognition signal, such as abnormalities in the signal level (amplitude). In addition, the connection detection unit can detect whether or not connection is possible from signals other than the recognition signal.

  As described above, the present invention is useful for a USB host device, particularly suitable for a USB host device capable of connecting a plurality of USB devices such as a POS terminal, and further suitable for a product sales system such as a POS system. Yes.

22 POS terminal (USB host device)
26 USB devices (USB devices)
24n USB host controller (recognition signal detector, connection detector)
44 switching control unit 45 time setting control unit Tr restart time

JP2008-152533

Claims (6)

A recognition signal detector for detecting a recognition signal from the connected universal serial bus device;
A switching control unit that switches supply and interruption of power to the connected universal serial bus device;
With
The universal serial bus host device, wherein the switching control unit restarts the power supply when the recognition signal abnormality is detected by the recognition signal detection unit and the power supply is cut off.   2. The switch control unit according to claim 1, wherein when the recognition signal detection unit detects an abnormality of the recognition signal, the switching control unit restarts the power supply after cutting off the power supply. Universal serial bus host device. A connection detector for detecting whether or not the universal serial bus device can be connected;
The switching control unit supplies the power when the connection detection unit detects that the universal serial bus device is not connected when the recognition signal abnormality is detected by the recognition signal detection unit. 3. The universal serial bus host device according to claim 1, wherein the universal serial bus host device is not restarted. The recognition signal is a signal in which a high level and a low level are switched at a predetermined cycle,
4. The universal serial bus host device according to claim 3, wherein the connection detection unit detects whether or not the universal serial bus device is connected based on the high level of the recognition signal.   The time setting control unit that variably sets a restart time from when the recognition signal abnormality is detected by the recognition signal detection unit to when the switching control unit restarts the supply of power. The universal serial bus host device according to any one of 1 to 4.   A program that causes a computer to function as the switching control unit of the universal serial bus host device according to any one of claims 1 to 5.

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