TWI413905B - Apparatus for testing usb ports - Google Patents

Abstract

An apparatus for testing usb (Universal Serial Bus) ports includes a current measurement device, a voltage comparator, an A/D (Analog to Digital) converter, a MCU (Micro Controller Unit), and a loading circuit. The current measurement device is used to measure an output current of an usb port. The voltage comparator is used to protect the loading circuit according to an indicating signal the voltage comparator itself outputs. The A/D converter is used to output a digital signal into which the A/D converter itself converts an analog signal. The MCU is used to examine the output current, an output voltage and four basic transmission properties of the usb port. With the apparatus, it is accomplished to detect both the basic transmission properties and the output current and the output voltage of the usb port.

Description

Universal serial bus enthalpy test device

The present invention relates to a test apparatus, and more particularly to a test apparatus for testing a power supply specification for a universal serial bus bar.

Most of the electronic devices currently in use are equipped with a universal serial bus. A universal serial bus is a serial bus that is used to connect external devices of an electronic device. Universal serial busbars are especially widely used on computers, but can also be used on set top boxes and gaming consoles. The universal serial bus can be used to allow direct exchange of data between the electronic device and its portable device (Universal Serial Bus Device, USB device).

After the user connects the USB device to the universal serial bus of the electronic device, the electronic device first detects whether the USB device has successfully connected to the universal serial bus. If the connection is successful, then the electronic device can exchange data with the USB device, thereby implementing the function of the USB device. Therefore, in order to verify that the universal serial bus of the electronic device can work normally, the tester or the user needs to perform the action of testing the quality problem of the general sequence bus when the electronic device is factory-inspected and routinely maintained.

In general, the general-purpose serial busbar specification requires that the supply voltage not exceed 5.25 volts. Thus, under normal operating conditions, the universal sequence bus bar provides a voltage between 4.75 and 5.25 volts, and the output current of the universal sequence bus bar does not exceed 500 milliamps (mA).

Therefore, when testing the performance of a general-purpose serial bus and transmitting data, it is usually done through a mouse, keyboard, joystick, printer, or mobile hard disk with a USB plug. During the test, the USB device can be inserted into the universal serial bus, and then the electronic device's test program can check whether the USB device is detected, and then it is detected whether the USB device can work normally. However, there is a problem with this type of test method: when the electronic device includes a plurality of general-purpose serial bus bars, the tester needs to insert each of the universal serial bus bars into one USB device. This procedure not only increases the complexity of the test process, but also makes the test time too long and inefficient.

In addition, in order to verify whether the supply voltage and current of the universal serial bus are in compliance with the specifications, the tester must additionally set other available voltages for detection outside the USB device for testing the performance of the general-purpose serial bus. , current testing device. Therefore, this action also increases the test cost of the universal serial bus.

Based on the above prior art, there is a problem of test cost and test complexity. The present invention proposes a universal sequence bus sputum test device for testing a universal sequence bus 一 of an electronic device.

The universal serial bus bar testing device comprises: a current detector, a voltage comparator, an analog data converter, a microcontroller and a load circuit.

A current detector can be used to detect an output current generated in the common sequence bus bar and generate an analog comparison voltage corresponding to the output current.

The voltage comparator can be used to output an indication signal according to the analog comparison voltage and a reference voltage.

An analog digital data converter can be used to connect the current detector to the universal serial bus to convert the analog comparison voltage to a analog output voltage generated in the universal serial bus 成 to a digital comparison voltage and a digital output voltage.

A microcontroller can be used to receive a differential signal, a digital comparison voltage, and a digital output voltage generated in a common sequence bus.

The load circuit can be connected between an output contact of the universal serial bus bar test device, the voltage comparator and the microcontroller. And, the load circuit can be used to form one of an on state and a off state according to the microcontroller and the indication signal.

Therefore, the universal sequence bus bar test device disclosed in one embodiment of the present invention can not only complete the test of the basic transmission type of the universal sequence bus, but also achieve the power supply specification (output voltage and output) at the same time. Current test function.

The above description of the present invention and the following embodiments are intended to illustrate and explain the spirit and principles of the invention, and to provide further explanation of the scope of the invention.

Please refer to "FIG. 1", which is a general-purpose serial busbar test device according to an embodiment of the present invention. Such a universal serial bus sputum test device can be used to test a universal serial bus 埠 10 of an electronic device.

The universal serial bus bar testing device includes a current detector 100, a voltage comparator 200, an analog digital data converter 300, a microcontroller 400, and a load circuit 500.

The universal serial bus 埠 10 includes four terminals, namely, an output terminal VBUS, a twisted pair positive terminal D+, a twisted pair negative terminal D-, and a ground GND.

The ground GND is used for grounding.

The output terminal VBUS can be used to output an analog output voltage V _{a of the} universal sequence bus 埠 10 and an output current I _o , and the output terminal VBUS can be used to connect the USB device.

The twisted pair positive terminal D+ and the twisted pair negative terminal D- can be used to provide a differential signal V _{dif '} and the differential signal V _dif can be used to drive a USB device, such as a universal serial bus bar test device.

As shown in FIG. 1, the current detector 100 is connected between the general-purpose serial bus bar 10, the load circuit 500, the analog-digital data converter 300, and the voltage comparator 200. The current detector 100 may be used to detect output current universal serial bus ports 10 of I _o, I _o and the output current comparator outputs an analog voltage V _ac.

Wherein, the analog comparison voltage V _ac corresponds to the output current I _o : when the output current I _{o is} less than 500 milliamps, the corresponding analog comparison voltage V _ac may be between 0 volts and 1 volt. When the output current I _{o is} greater than 500 mA, the corresponding analog comparison voltage V _ac will be between 1 volt and 2 volts.

For a detailed diagram of the current detector 100, please refer to "Figure 2". According to an embodiment of the invention, current detector 100 includes a current monitoring unit 102 and a monitoring resistor 104.

The current monitoring unit 102 includes a plurality of pins, which are respectively connected to the ground GND, a power source VCC, the output terminal VBUS of the universal serial bus bar 10, an output contact V _R , and the voltage comparator 200 and Analog digital data converter 300.

The monitoring resistor 104 is connected between the output terminal VBUS of the universal serial bus bar 10 and the output contact V _R . Current monitoring unit 102 may be used to monitor the resistance value of the resistor 104 and the voltage drop across the sensing resistor 104, the calculated Universal Serial Bus ports of the output current I _o 10.

The current monitoring unit 102 can include six pins, but it is worth mentioning that the unit elements that can achieve the current monitoring function are not limited to six pins. For clarity of illustration, the current monitoring unit 102, which has a number of pins of six, is disclosed above.

The positive input of voltage comparator 200 is coupled to the junction of current detector 100 and analog digital data converter 300. The negative input of voltage comparator 200 is coupled to a reference voltage V _ref , where reference voltage V _ref is 1 volt. The output of the voltage comparator 200 is connected to the load circuit 500. With this connection relationship, the voltage comparator 200 can be used to receive the analog comparison voltage V _ac , compare the analog comparison voltage V _ac with the reference voltage V _ref and output an indication signal V _ind . Wherein, the indication signal V _ind can be used to control the conduction state of the load circuit 500. When the analog comparison voltage V _{ac is} between 1 volt and 2 volts, the indication signal V _ind is at a high level. Conversely, when the analog comparison voltage V _{ac is} between 0 volts and 1 volt, the indication signal V _ind is at a low level.

The input of the analog digital data converter 300 can be used to connect the output VBUS of the universal serial bus 埠 10 with the current detector 100. By this connection relationship, the analog digital data converter 300 can be used to read the analog output voltage V _a and the analog comparison voltage V _ac .

Since the analog digital data converter 300 can be used to convert the analog signal into a digital signal. Therefore, the analog digital data converter 300 can be used to output a digital output voltage V _D and a digital comparison voltage V _dc . Wherein, the digital output voltage V _D corresponds to the analog output voltage V _a , and the digital comparison voltage V _dc corresponds to the analog comparison voltage V _ac .

The output of the analog digital data converter 300 can be used to connect an electrically-erasable programmable read-only memory 600 to the microcontroller 400. The electrically erasable programmable read only memory 600 can be used to temporarily store the memory state of the analog digital data converter 300, and the microcontroller 400 can be used to read the analog output voltage V _a corresponding to the universal serial bus bar 10 Digital output voltage V _D .

The input of the microcontroller 400 can be used to connect the twisted pair positive terminal D+ of the universal serial busbar 10, the twisted pair negative terminal D- and the analog digital data converter 300. With this connection, the microcontroller 400 can be used to receive the differential signal V _dif , the digital output voltage V _{D of the} universal sequence bus 埠 10, and the digital comparison voltage V _dc . The microcontroller 400 can also be pushed back by the digital comparison voltage V _dc to obtain the output current I _{o of the} universal serial bus 埠 10 . Therefore, the universal serial bus bar test apparatus according to an embodiment of the present invention can test the digital output voltage V _D and the output current I _{o of the} universal serial bus bar 10 by the above-described mechanism connection and principle.

In addition, the microcontroller 400 is further configured to be connected between an input signal unit 700 and the load circuit 500, and the actuation relationship is as shown in FIG. 3. The input signal unit 700 includes a switching element S ₁ and an input resistor R ₆ . The switching element S _{1 is} connected between the microcontroller 400 and a first output voltage V _s . One end of the input resistor R ₆ is connected to the contact of the microcontroller 400 and the switching element S ₁ , and the other end of the input resistor R ₆ is grounded. Here, the first output voltage V _s can be 3.3 volts.

When the switching element S ₁ is turned off, the microcontroller 400 is forcibly connected to the first output voltage V _s by the input signal unit 700. Therefore, the microcontroller 400 generates a low level error signal V _err and the microcontroller 400 can control the load circuit 500 by the error signal V _err .

Since the load circuit 500 is connected to the universal serial bus 埠 10 by the current detector 100, when the switching element S ₁ is turned off, the microcontroller 400 forcibly turns on the load circuit 500 by the low level error signal V _err . . In this case, universal serial bus ports of the output current I _o 10 more than 500 mA, and the analog comparison voltage V _ac 100 output from the current detector between 1 volt to 2 volts. Therefore, the indication signal V _ind output by the voltage comparator 200 is at a high level. Thus, the load circuit 500 is then forced to turn off. Therefore, the voltage comparator 200 can thus achieve the purpose of protecting the universal serial busbar test device disclosed in one embodiment of the present invention.

The output of the microcontroller 400 according to an embodiment of the present invention may further be used to connect a display state unit 800, a communication conversion circuit 900, and a static random access memory (SRAM) 910. The static random access memory 910 can be used to store the memory data of the microcontroller 400.

As shown in "FIG. 4", the status display unit 800 comprises a light emitting diode D ₁ and a display resistor R _5. The light emitting diode D _{1 is} connected between the microcontroller 400 and the display resistor R ₅ . One end of the display resistor R ₅ is connected to the light-emitting diode D ₁ , and the other end of the display resistor R ₅ is connected to the first output voltage V _s . When the universal serial bus bar test device of one embodiment of the present invention is connected to the universal sequence bus bar 10 and the microcontroller 400 receives the differential signal V _dif , the light emitting diode D ₁ emits light. Therefore, the display status unit 800 can thereby display the connection status of the microcontroller 400 with the universal serial bus.

Next, please refer to "Fig. 1" and "Fig. 5" at the same time, wherein "Fig. 5" is a communication conversion circuit 900 according to an embodiment of the present invention. The communication conversion circuit 900 is coupled to the microcontroller 400 and can be used to convert the output interface of the microcontroller 400. According to an embodiment of the invention, the communication conversion circuit 900 can be a communication conversion chip (MAX3232). The internal structure of the communication conversion chip (MAX3232) is shown in FIG. 5: the communication conversion circuit 900 includes a circuit component U ₁ , a first capacitor C ₁ , a second capacitor C ₂ , and a third capacitor C _{3 .} a fourth capacitor C _4, a fifth capacitor C _5, a first output means J ₁ and the output of a second J _2.

The circuit component U _{1 is} connected to the microcontroller 400.

The first capacitor C _{1 is} connected between the first pin 1 and the second pin 2 of the circuit element U ₁ .

The second capacitor C _{2 is} connected between the third pin 3 and the fourth pin 4 of the circuit element U ₁ .

The third capacitor C _{3 is} connected between the fifth pin 5 of the circuit element U ₁ and the ground.

The fourth capacitor C _{4 is} connected between the sixth pin 6 of the circuit element U ₁ and the ground.

The fifth capacitor C _{5 is} connected between the seventh pin 7 of the circuit element U ₁ and the ground.

The first outputter J _{1 is} connected to the eighth pin 8 and the ninth pin 9 of the circuit element U ₁ and to the ground.

The second output J _{2 is} connected to the tenth pin 10 and the eleventh pin 11 of the circuit element U ₁ and to the ground.

Wherein, according to an embodiment of the present invention, the fifth pin 5 can be connected to the first output voltage V _s to supply the circuit element U ₁ power. And the first outputter J ₁ and the second outputter J ₂ are both Universal Asynchronous Receiver/Transmitter (UART). The communication conversion circuit 900 can be used to convert the output TTL interface of the microcontroller 400 to the RS-232 interface. The universal serial bus bar test device of one embodiment of the present invention can be used to communicate with other serial ports of the electronic device by the interface conversion function of the communication conversion circuit 900.

Please refer to FIG. 6 , which is a load circuit 500 of a universal serial bus bar test device according to an embodiment of the present invention. The load circuit 500 includes a first resistor R ₁ , a second resistor R ₂ , a third resistor R ₃ , a fourth resistor R ₄ , a first transistor Q ₁ , a second transistor Q ₂ , and a first The three transistors Q ₃ , a fourth transistor Q ₄ and a load resistor R _1d .

The base of the first transistor Q ₁ is connected to the voltage comparator 200 and the source of the first transistor Q ₁ is grounded.

The base of the second transistor Q ₂ is connected to the microcontroller 400 and the source of the second transistor Q ₂ is grounded.

The first resistor R _{1 is} coupled to the junction of the voltage comparator 200 and the base of the first transistor Q ₁ .

The second resistor R _{2 is} coupled to the junction of the microcontroller 400 and the base of the second transistor Q ₂ .

The base of the third transistor Q ₃ is connected to the drain of the second transistor Q ₂ and the source of the third transistor Q ₃ is grounded.

The base of the fourth transistor Q ₄ is connected to the drain of the first transistor Q ₁ and the source of the fourth transistor Q ₄ is connected to the drain of the third transistor Q ₃ .

The third resistor R _{3 is} connected to the junction of the base of the third transistor Q ₃ and the drain of the second transistor Q ₂ .

The fourth resistor R _{4 is} connected to the junction of the base of the fourth transistor Q ₄ and the drain of the first transistor Q ₁ .

The load resistor R _{1d is} connected between the output contact V _R and the drain of the fourth transistor Q ₄ .

Universal serial bus ports, one embodiment of the test apparatus according to the present invention, wherein the applied voltage 3.3 volts each in contact with one end of _a second resistor R ₂ of the first floating resistor R, the third resistor R ₃ One end of the floating connection with the fourth resistor R ₄ is applied with a voltage value of 5 volts.

In the general-purpose serial bus/drain test apparatus according to an embodiment of the present invention, as shown in FIG. 1, a regulator LDO can be connected to the output contact V _R . Among them, the regulator LDO can be used to step down. According to an embodiment of the invention, the regulator LDO is connected to the universal serial busbar 10 via the current detector 100. Therefore, the regulator LDO can be used to reduce the analog output voltage V _{a of the} universal serial bus 埠 10 to a lower voltage output for use by other serial ports of the electronic device. In accordance with an exemplary serial bus bar testing apparatus in accordance with an embodiment of the present invention, a voltage regulator LDO can be used to reverse a voltage of 5 volts and output a voltage of 3.3 volts.

Furthermore, the microcontroller 400 of one embodiment of the present invention may be an EZ-USB chip of the FX2LP series, model number CY7C68013A, produced by Cypress Corporation. This wafer is a high performance wafer with an interface for connecting a universal serial busbar of an electronic device. The chip mainly includes a USB2.0 transceiver, a data processing engine and an enhanced 8051 processing core. The rest of the unit components are not described here.

Since the microcontroller 400 is a high-performance chip combined with a data processing engine, the microcontroller 400 can be used not only to implement the above-described functions of detecting the output voltage and output current of the universal serial bus 埠 10, but also to test the universal sequence. The four types of transmissions required for bus 埠 10: control transmission, interrupt transmission, bulk transmission and synchronous transmission.

Wherein, when the universal sequence bus bar test device is successfully connected with the universal sequence bus bar 10 and can be correctly recognized by the electronic device, the control transfer function can be regarded as normal.

After the electronic device transmits an interrupt signal to the universal serial bus bar test device via the universal serial bus bar 10, if the electronic device can receive the response message of the universal sequence bus bar test device within the limited time, the electronic device can be regarded as the interrupt transmission. functioning normally.

After the electronic device transmits a data signal to the universal serial bus test device via the universal serial bus, the electronic device can receive a signal returned from the universal serial bus test device, and the content of the signal is equivalent. When the data signal is sent, it can be regarded as normal for the bulk transfer function.

The requirement for synchronous transmission is looser. As long as the universal serial bus sputum test device can complete the transmission and reception of signals with the electronic device, the synchronous transmission function can be regarded as normal.

Therefore, the general-purpose serial bus sputum test apparatus of an embodiment of the present invention can perform the test of the above four types of transmissions not only by the microcontroller 400, but also by the universal sequence bus arrangement of an embodiment of the present invention. The current detector 100, the voltage comparator 200, the analog digital data converter 300, the microcontroller 400, and the load circuit 500 included in the test apparatus complete the test of the power supply specification (output voltage and output current) of the universal serial bus 埠10. Features.

While the present invention has been described above in its preferred embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of patent protection shall be subject to the definition of the scope of the patent application attached to this specification.

10. . . Universal sequence bus

100. . . Current detector

102. . . Current monitoring unit

104. . . Monitoring resistor

200. . . Voltage comparator

300. . . Analog digital data converter

400. . . Microcontroller

500. . . Load circuit

600. . . Electric wiping programmable read-only memory

700. . . Input signal unit

800. . . Display status unit

900. . . Communication conversion circuit

910. . . Static random access memory

VBUS. . . Output

D+. . . Twisted pair positive end

D-. . . Twisted pair negative end

GND. . . Ground terminal

VCC. . . power supply

V _a . . . Analog output voltage

I _o . . . Output current

V _dif . . . Differential signal

V _ac . . . Analog comparison voltage

V _R . . . Output contact

V _ref . . . Reference voltage

V _ind . . . Indication signal

V _D . . . Digital output voltage

V _dc . . . Digital comparison voltage

S ₁ . . . Switching element

R ₆ . . . Input resistance

V _s . . . First output voltage

V _err . . . Error signal

D ₁ . . . Light-emitting diode

R ₅ . . . Display resistance

U ₁ . . . Circuit component

C ₁ . . . First capacitor

C ₂ . . . Second capacitor

C ₃ . . . Third capacitor

C ₄ . . . Fourth capacitor

C ₅ . . . Fifth capacitor

J ₁ . . . First output

J ₂ . . . Second output

1. . . First pin

2. . . Second pin

3. . . Third pin

4. . . Fourth pin

5. . . Fifth pin

6. . . Sixth pin

7. . . Seventh pin

8. . . Eighth pin

9. . . Ninth pin

10. . . Tenth pin

11. . . Eleventh pin

R ₁ . . . First resistance

R ₂ . . . Second resistance

R ₃ . . . Third resistance

R ₄ . . . Fourth resistor

Q ₁ . . . First transistor

Q ₂ . . . Second transistor

Q ₃ . . . Third transistor

Q ₄ . . . Fourth transistor

R _1d . . . Load Resistance

LDO. . . Stabilizer

1 is a schematic structural diagram of a universal serial bus enthalpy test apparatus according to an embodiment of the present invention;

Figure 2 is a schematic illustration of a current detector in accordance with an embodiment of the present invention;

Figure 3 is a schematic illustration of an input signal unit in accordance with an embodiment of the present invention;

Figure 4 is a schematic illustration of a display state unit in accordance with an embodiment of the present invention;

Figure 5 is a schematic diagram of a communication conversion circuit in accordance with an embodiment of the present invention;

Figure 6 is a schematic diagram of a load circuit in accordance with an embodiment of the present invention.

10. . . Universal sequence bus

100. . . Current detector

200. . . Voltage comparator

300. . . Analog digital data converter

400. . . Microcontroller

500. . . Load circuit

600. . . Electric wiping programmable read-only memory

700. . . Input signal unit

800. . . Display status unit

900. . . Communication conversion circuit

910. . . Static random access memory

VBUS. . . Output

D+. . . Twisted pair positive end

D-. . . Twisted pair negative end

GND. . . Ground terminal

V _a . . . Analog output voltage

I _o . . . Output current

V _dif . . . Differential signal

V _ac . . . Analog comparison voltage

V _R . . . Output contact

V _ref . . . Reference voltage

V _ind . . . Indication signal

V _D . . . Digital output voltage

V _dc . . . Digital comparison voltage

V _s . . . First output voltage

V _err . . . Error signal

LDO. . . Stabilizer

Claims (10)

A universal serial bus flow test device for testing a general sequence sink flow of an electronic device, the universal sequence sink flow test device comprising: a current detector for detecting the general sequence sink generated Discharging an output current of the buffer to generate a corresponding analog voltage; a voltage comparator for outputting an indication signal according to the analog comparison voltage and a reference voltage; and an analog digital converter connected to the current detector The universal sequence is arranged to convert the analog voltage and a analog output voltage generated in the general sequence sink into a digital comparison voltage and a digital output voltage; a microcontroller is configured to receive the a differential signal of the general sequence sink, the digital comparison voltage and the digital output voltage; and a load circuit coupled to an output contact of the universal serial bus flow test device, the voltage comparator and the Between the microcontrollers, the load circuit is configured to form one of an on state and a off state according to the microcontroller and the indication signal. The universal sequence sinking rogue testing device of claim 1, further comprising: at least one input signal unit, each of the input signal units being coupled to the microcontroller, and configured to generate an error signal to cause the microcontroller The load circuit is controlled according to the error signal. The universal sequence sinking test device of claim 2, wherein each of the input signal units comprises: a switching element connected between the microcontroller and a first output voltage; and an input resistor, the input One end of the resistor is connected to the junction of the microcontroller and the switching element, and the other end of the input resistor is grounded. The universal sequence sinking rogue testing device of claim 1, further comprising: at least one display state unit, each of the display state units being coupled to the microcontroller for displaying the microcontroller and the universal sequence The connection status of 埠. The universal sequence sinking flow testing device according to claim 4, wherein each of the display state units comprises: a light emitting diode connected to the microcontroller; and a display resistor connected to the light emitting diode relative to The other end of the microcontroller is between a first output voltage. The universal sequence sinking rogue testing device of claim 1, wherein the current detector comprises: a current monitoring unit connected to the ground, a power source, the universal sequence sink, the output contact, the voltage a comparator and the analog digital data converter; and a monitoring resistor coupled between the universal serial bus and the output contact. The universal sequence sinking test device of claim 1, wherein the load circuit comprises: a first transistor, a base of the first transistor is connected to the voltage comparator and a source of the first transistor Grounding; a second transistor, a base of the second transistor is coupled to the microcontroller and a source of the second transistor is grounded; a first resistor coupled to the voltage comparator and the first transistor a base contact; a second resistor connected to the junction of the microcontroller and the base of the second transistor; a third transistor having a base connected to the second transistor a drain of the third transistor and a source of the third transistor; a fourth transistor having a base connected to the drain of the first transistor and a source of the fourth transistor connected to the third a drain of the transistor; a third resistor connected to the junction of the base of the third transistor and the drain of the second transistor; a fourth resistor connected to the base of the fourth transistor a junction of the drain of the first transistor; and a load resistor coupled to the output contact and the fourth Between the bungee of the transistor. The universal sequence sinking test device as claimed in claim 1, further comprising a communication conversion circuit connected to the microcontroller to convert the output interface of the microcontroller. The universal sequence bus-flow testing device according to claim 8, wherein the communication conversion circuit comprises: a circuit component connected to the microcontroller; a first capacitor connected to a first pin of the circuit component a second capacitor is connected between a third pin and a fourth pin of the circuit component; a third capacitor is connected to a fifth pin of the circuit component Between the grounding; a fourth capacitor connected between a sixth pin of the circuit component and the ground; a fifth capacitor connected between a seventh pin of the circuit component and the ground; a first output And an eighth output pin connected to the circuit component, a ninth pin and a ground; and a second output device connected to a tenth pin, an eleventh pin and the ground of the circuit component. The universal sequence sinking test device of claim 9, wherein the first output device and the second output device are universal asynchronous transceiver transmitters.