USB-testing method and testing fixture board for USB device

The present invention relates to technology of testing input/output interfaces which comply with USB 3.0 standard and, more particularly, to a universal serial bus (USB) testing method and a testing fixture board for a USB device.

Universal serial bus (USB) interface is the input/output interface most widely used. A USB device, such as a mouse, keyboard, printer, hard disk drive, USB flash drive, camera, cellular phone, tablet, laptop, personal computer, set-top box, or game console, can be linked to another USB device by the USB interface in order to exchange data.

To test and determine whether USB interfaces of USB devices function well, USB device delivery inspection requires a testing worker to conduct a quality test on the USB interfaces. Regarding the physical layer testing specifications of USB 2.0, USB Implementers Forum (USB IF) sets forth three testing specifications for low speed, full speed, and high speed, respectively. The USB High-Speed Electrical Test Tool provided by the USB IF controls how a USB device under test sends specific testing packets when operated by a conventional operating system, and the testing packets are observed with an oscilloscope to confirm the compatibility and signal quality of the USB interface of the USB device which meets USB 2.0 standard.

Unlike USB 2.0 standard, USB 3.0 standard features greatly simplified testing specifications and testing techniques. USB 3.0 interface chips of USB devices operated by a conventional operating system are preconfigured with a test mode. In the situation where connecting a USB device under test to a testing fixture board is not followed by any response for a while, a USB interface chip mounted on the USB device under test enters a compatibility mode directly. In the compatibility mode, the USB device under test starts sending testing packets so that an oscilloscope measures the testing packets through the testing fixture board and displays the measured testing packets, allowing a testing worker to confirm and support the compatibility and signal quality of the USB interface of the USB device under test.

However, testing techniques applicable to USB 3.0 interfaces are useless to a USB device with a USB 3.0 interface, if the USB device is an embedded system.

In an embodiment, a universal serial bus (USB) testing method comprises the steps of: selecting a selected test mode from a plurality of test modes; creating a USB communication link between a USB device and a testing fixture board; generating, by the testing fixture board, a test-triggering instruction corresponding to the selected test mode according to the selected test mode; sending the test-triggering instruction to the USB device with the USB communication link; generating, by the USB device, a testing packet corresponding to the selected test mode according to the test-triggering instruction; and outputting the testing packet repeatedly from at least one external port of the USB device.

In an embodiment, a testing fixture board for a USB device comprises a substrate, a storage unit, a USB port, a user interface and a control unit. The storage unit, USB port, user interface and control unit are disposed on the substrate. The control unit is coupled to the storage unit, USB port and user interface. The storage unit stores a list of a selection signal and a test-triggering instruction for each of a plurality of test modes. The user interface generates a selection signal indicative of a selected test mode among the plurality of test modes. The control unit generates the test-triggering instruction corresponding to the selected test mode according to the selection signal and the list and sends the test-triggering instruction from the USB port.

In conclusion, a USB testing method and a testing fixture board for a USB device provided according to the present invention are applicable to a USB device operated by an embedded operating system with a view to triggering the USB device to test a USB interface thereof, thereby testing the compatibility and signal quality of the USB interface easily.

FIG. 1 is a schematic block diagram of a testing fixture board for a universal serial bus (USB) device according to an embodiment of the present invention;

FIG. 2 is a schematic view of application of the testing fixture board in FIG. 1 ;

FIG. 3 is a flowchart of a USB testing method according to an embodiment of the present invention;

FIG. 4 is a schematic block diagram of a measuring device for the USB device according to an embodiment of the present invention;

FIG. 5 is a schematic view of application of the measuring device in FIG. 4 ;

FIG. 6 is a schematic block diagram of another testing fixture board according to another embodiment of the present invention;

FIG. 7 is a schematic view of application of the testing fixture board in FIG. 6 ;

FIG. 8 is a schematic block diagram of the measuring device according to another embodiment of the present invention; and

FIG. 9 is a schematic block diagram of the measuring device according to yet another embodiment of the present invention.

FIG. 1 is a schematic block diagram of a testing fixture board for a universal serial bus (USB) device according to an embodiment of the present invention. Referring to FIG. 1 , a testing fixture board 10 for a USB device (hereinafter referred to as the testing fixture board 10 ) comprises a substrate 110 , a storage unit 130 , a USB port 150 , a user interface 170 and a control unit 190 . The storage unit 130 , USB port 150 , user interface 170 and control unit 190 are disposed on the substrate 110 . The control unit 190 is coupled to the storage unit 130 , USB port 150 and user interface 170 . The storage unit 130 stores a list which shows a selection signal and a test-triggering instruction EN for each of a plurality of test modes, as shown in Table 1. In an embodiment, each test-triggering instruction EN is an identifier. The identifier is, for example, a vendor ID (VID) and/or a product ID (PID).

The description below is exemplified by one USB port 150 , but the present invention is not limited thereto. In a variant embodiment, the testing fixture board 10 comprises a plurality of USB ports 150 .

FIG. 2 is a schematic view of application of the testing fixture board in FIG. 1 . FIG. 3 is a flowchart of a USB testing method according to an embodiment of the present invention. Referring to FIG. 1 , FIG. 2 and FIG. 3 , to test a USB interface of a USB device 20 , a user selects one (hereinafter referred to as the selected test mode) of a plurality of test modes by controlling the user interface 170 so that the user interface 170 generates a selection signal (one of S 1 ˜S 11 ) indicative of the selected test mode according to the user's input (step S 01 ). Then, the user uses a connection line 30 to connect the USB port 150 of the testing fixture board 10 to an external port 250 of the USB device 20 to be tested, so as to create a USB communication link between the USB device 20 and the testing fixture board 10 (step S 02 ). The control unit 190 receives the selection signal from the user interface 170 and generates the test-triggering instruction EN corresponding to the selected test mode according to the selection signal and the list (step S 03 ). The USB device 20 is an embedded device and is operated by an embedded operating system.

For example, given the list shown in Table 1, if the selected test mode selected by the user is “Test_J,” the user interface 170 generates selection signal S 2 according to the user's input. The control unit 190 reads from the list of the storage unit 130 the test-triggering instruction EN “0x0102” corresponding to selection signal S 2 according to selection signal S 2 .

The control unit 190 sends the test-triggering instruction EN to the USB device 20 with the USB communication link (step S 04 ). Specifically speaking, the control unit 190 sends the test-triggering instruction EN from the USB port 150 to the USB device 20 with the connection line 30 via the external port 250 .

After receiving the test-triggering instruction EN, the USB device 20 generates a testing packet corresponding to the selected test mode according to the received test-triggering instruction EN (step S 05 ). Afterward, the testing packet is repeatedly outputted from an external port (such as the external port 250 for use in creating the USB communication link or any other applicable external port) of the USB device 20 (step S 06 ). For example, the USB device 20 comprises a USB chip 230 . The USB chip 230 is coupled to the external port 250 and adapted to control data transmission of the external port 250 . After receiving the test-triggering instruction EN with the external port 250 , the USB chip 230 reads a related testing packet from a built-in storage unit according to the received test-triggering instruction EN and outputs the testing packet repeatedly from the external port 250 , thereby allowing USB testing to be carried out in the selected test mode.

FIG. 4 is a schematic block diagram of a measuring device for the USB device according to an embodiment of the present invention. FIG. 5 is a schematic view of application of the measuring device in FIG. 4 . Referring to FIG. 4 and FIG. 5 , in an embodiment, after the USB device 20 started outputting the testing packet Pk repeatedly (step S 06 ), the user measures the testing packet Pk outputted from the USB device 20 with a measuring device 40 and confirms the result of the USB testing of the selected test mode in accordance with a measurement result of the measuring device 40 . For example, after the USB device 20 started outputting the testing packet Pk repeatedly (step S 06 ), the user severs the USB communication link between the USB device 20 and the testing fixture board 10 and connects the measuring device 40 to the external port 250 of the USB device 20 with a connection line 32 , so as to create a communication link between the measuring device 40 and the USB device 20 . Afterward, the measuring device 40 starts measuring the testing packet Pk outputted from the USB device 20 .

In an embodiment, the USB chip 230 of the USB device 20 is coupled to the external port 250 , as shown in FIG. 1 . The testing fixture board 10 and the measuring device 40 are each connected to the USB device 20 by the communication link via the external port 250 .

FIG. 6 is a schematic block diagram of another testing fixture board according to another embodiment of the present invention. FIG. 7 is a schematic view of application of the testing fixture board in FIG. 6 . In another embodiment, the USB chip 230 of the USB device 20 is coupled to the external ports 250 , 252 , as shown in FIG. 6 and FIG. 7 , respectively. The testing fixture board 10 and the measuring device 40 are each connected to the USB device 20 by the communication link via the external port 250 , as shown in FIG. 8 . Alternatively, the testing fixture board 10 and the measuring device 40 are connected to the USB device 20 by the communication link via the external ports 250 , 252 , respectively; for example, the testing fixture board 10 is coupled to the external port 250 of the USB device 20 , whereas the external port 250 is coupled to the external port 252 of the USB device 20 , as shown in FIG. 7 and FIG. 9 .

In an embodiment, the external port 250 / 252 is a USB port or a circular mil-spec port. The USB port is a standard USB port, mini USB port, micro USB port, or type C USB port.

In an embodiment, the storage unit 130 and the control unit 190 are implemented by a microcontroller 120 , as shown in FIG. 2 and FIG. 7 . The microcontroller is, for example, a USB chip, but the present invention is not limited thereto. In an embodiment, a USB chip of the testing fixture board 10 is substantially identical to the USB chip 230 of the USB device 20 . The USB chip 230 meets USB 3.0 standard.

In an embodiment, the measuring device 40 comprises an oscilloscope 410 (shown in FIG. 4 , FIG. 5 , FIG. 7 and FIG. 8 ,) and a measurement result shown on the oscilloscope 410 is a waveform diagram, such as an eye pattern. Therefore, the user observes a waveform, an operating voltage, and/or the other signal features in the waveform diagram to evaluate the compatibility and signal quality of the USB interface. In an embodiment, the measuring device 40 further comprises another testing fixture board 430 (shown in FIG. 4 , FIG. 5 , FIG. 7 and FIG. 8 ,) and the testing fixture board 430 is coupled between the USB device 20 and the oscilloscope 410 . The testing fixture board 430 is conducive to signal transmission between the USB device 20 and the oscilloscope 410 , for example, by sending the testing packets to the oscilloscope 410 .

In an embodiment, the measuring device 40 is built-in with various standard templates for the test modes. The measuring device 40 compares a received testing packet with a standard template for the selected test mode to determine whether the USB testing carried out in the selected test mode is satisfactory (it will be determined to be satisfactory, provided that the received testing packet matches the standard template.) In an embodiment, the measuring device 40 uses its user interface to identify an ongoing test mode according to the user's input, read a standard template for the selected test mode, and compare the standard template with the received testing packet. In another embodiment, the measuring device 40 compares the received testing packets with all the built-in standard templates one by one to determine whether each testing packet matches any one of the standard templates. If the testing packet matches one of the standard templates, the measuring device 40 will determine that the USB testing carried out in the selected test mode is satisfactory. If the testing packet matches none of the standard templates, the measuring device 40 will determine that the USB testing carried out in the selected test mode is unsatisfactory.

In an embodiment, to carry out the USB testing in another test mode, the user controls the user interface 170 anew in order to select a desired test mode, causing the testing fixture board 10 to generate and send another test-triggering instruction to the USB device 20 . Afterward, the USB device 20 generates and sends repeatedly another testing packet according to the newly-received test-triggering instruction, that is, following steps S 01 ˜S 06 again.

In an embodiment, the USB device 20 is a host or an OTG (on-to-go) device and is exemplified by a mouse, keyboard, printer, fax machine, photocopier, hard disk drive, USB flash drive, camera, cellular phone, tablet, laptop, personal computer, set-top box, or game console.

In conclusion, a USB testing method and a testing fixture board for a USB device provided according to the present invention are applicable to a USB device operated by an embedded operating system with a view to triggering the USB device to test a USB interface thereof, thereby testing the compatibility and signal quality of the USB interface easily.