CN201037934Y

CN201037934Y - Universal serial bus load detecting device

Info

Publication number: CN201037934Y
Application number: CNU200720050920XU
Authority: CN
Inventors: 吕皇庆; 温增兴
Original assignee: Mitac Computer Shunde Ltd; Mitac International Corp
Current assignee: Mitac Computer Shunde Ltd; Shunda Computer Factory Co Ltd; Mitac International Corp
Priority date: 2007-04-28
Filing date: 2007-04-28
Publication date: 2008-03-19
Anticipated expiration: 2017-04-28

Abstract

The utility model discloses a common serial bus load detecting device, which detects the largest admitting load of the host end of the awaiting common serial bus. A USB load detecting device comprises a simulating USB device; a micro-processor is electrically connected with the simulating USB device; a simulating signal detecting circuit is electrically connected with the simulating USB device; a load control unit is electrically connected with the micro-processor to receive modulating signal transmitted from the micro-processor and increase load of the simulating USB device to the largest admitting load of the awaiting USB. The common serial bus load detecting device can detect the largest load of the awaiting USB and improves the problem earlier that system is affected due to oversized USB load.

Description

The USB (universal serial bus) Weight detector

Technical field

The utility model relates to a kind of USB (universal serial bus) (Universal Serial Bus; USB) Weight detector, but particularly a kind of USB (universal serial bus) Weight detector of maximum current load of fast detecting USB (universal serial bus).

Background technology

USB (universal serial bus) (Universal Serial Bus; USB) be the interfacing equipment interface of a new generation, it is by Intel, Compaq, NEC, DEC, IBM, the common formulation of seven tame software and hardware institutes of manufacturer such as Northern Telecom, Microsoft, the transfer rate of this kind interface has 1.5Mbps and two kinds of forms of 12Mbps, can be connected to 127 interfacing equipments at most, because its transfer rate is all fast many compared with employed parallel port of PC or serial port, so USB all has apparent lifting for the transfer efficiency of computer equipment and perimeter interface.

The operating system of computer system or notebook computer is all supported USB interface now, the peripheral PORT COM of computer system or notebook computer all has unified formulation specification, for example support peripheral devices such as USB interface network card, hub, keyboard, mouse, joystick, CD-ROM drive, magnetic tape station, printer, scanner, digital camera, all interfacing equipments have almost been comprised, these USB devices are not only supported the ability of plug and play (Plug andPlay), and needn't start shooting again and just can use (Hot Swap).Therefore, by USB, dissimilar interfacing equipments such as mouse, keyboard, joystick, loudspeaker, modulator-demodular unit, scanner, CD-ROM drive or the like can be connected on computers by identical interface, thereby have simplified PC connecting interface type.In addition, USB also has advantages such as cost is low, connection device is many, occupying system resources is few, the multiple transport-type of support, provides the consumer to use great convenience undoubtedly.

Though USB device now all has the specification of standard,, after detecting new USB device, host computer (Host) end just can provide the user to utilize to connect the USB port (ports) of computer.Yet, how to learn that above-mentioned host computer end can bear the USB device and connects the maximum current load after the USB port or connect the normal operation that can or can not have influence on computer system under the fully loaded situation in bearing the USB device when the host computer end, the maximum current load of the USB port of known detection host computer measures its actuation voltage (port droop) to single USB port with host computer and learns the voltage-current relationship of this USB port under the fully loaded situation of USB port, can obtain the maximum current load (current margin) of this USB port, yet, the very inconvenience and have no efficient of this detection mode, if when the computer volume production, will have the secret worry of the fiduciary level and the stability of product quality, also easily cause the increase of cost recovery, therefore how the pick-up unit and the detection method thereof of a kind of maximum current load that can fast detecting USB device of output will be the problems that industry is desired most ardently solution.

The utility model content

In view of above problem, fundamental purpose of the present utility model is to provide a kind of USB (universal serial bus) (Universal Serial Bus; USB) Weight detector is effectively and apace to detect the maximum load of USB device to be measured.

According to above-mentioned purpose, the utility model discloses a kind of USB (universal serial bus) (Universal Serial Bus; USB) Weight detector is in order to detect a USB host end to be measured (Device under testUSB Host; DUT USB Host) maximum permissible load, this USB Weight detector comprises: an emulation USB device, it has two power leads and binary signal line, to be connected with this usb host end to be measured; One microprocessor is electrically connected this emulation USB device, and has the two pin positions corresponding with two power leads of this emulation USB device; One simulate signal circuit for detecting is electrically connected this emulation USB device, and has the two pin positions corresponding with the binary signal line of this emulation USB device; And a load control unit, electricity connects this microprocessor, to receive the modulation signal that this microprocessor transmitted and increase this maximum permissible load that is loaded to this USB to be measured of emulation USB device.

USB Weight detector of the present utility model can be reached following effect:

1, compatible high, do not need extra driver;

2, it is excessive and influence the problem of system to improve the USB load ahead of time;

3, simple to operate, detect fast.

More than about the explanation of the utility model content and following embodiment explanation in order to demonstration with explain principle of the present invention.

Description of drawings

Fig. 1 is the functional block diagram of the utility model USB (universal serial bus) Weight detector.

Fig. 2 detects the process flow diagram of the maximum load of usb host end to be measured for the utility model USB Weight detector.

Embodiment

Please refer to Fig. 1, be the utility model USB (universal serial bus) (Universal Serial Bus; USB) functional block diagram of Weight detector.This USB Weight detector 10 is in order to detect a USB host end to be measured (Device under test USB Host; DUT USB Host) 70 maximum permissible load, USB Weight detector 10 comprise an emulation USB device 20, a microprocessor (Micro Control Unit; MCU) 30, one load control unit 40, a simulate signal circuit for detecting 50 and a display device 60.

Be connected to four lines (not shown) in the usb host end 70 to be measured altogether, be respectively: Vcc, Gnd, D+ and D-, Vcc and Gnd are power lead; D+ and D-are pair twist (twist paired) signal wire.So emulation USB device 20 of the present utility model also designs corresponding Vcc, Gnd, D+ and the D-pin position that connects usb host end 70 to be measured.

Microprocessor 30 of the present utility model is a single-chip processor, it has two pin position V and G is electrically connected on emulation USB device 20 pairing Vcc and Gnd pin position respectively, recording the load result of emulation USB device 20, and export a modulation signal T in order to the voltage signal that receives emulation USB device 20.

Simulate signal circuit for detecting 50 has two pin position D1 and D2 is electrically connected on emulation USB device 20 pairing D+ and D-pin position respectively, in order to receive the signal condition of emulation 20 corresponding D+ of USB device and D-pin position.When D+ and D-pin position connect noble potential, D1 and signal that D2 detects are " 1 ", and expression emulation USB device 20 is under the normal load situation, when D+ and D-pin position connect electronegative potential, D1 and signal that D2 detects are " 0 ", and expression emulation USB device 20 is under the fully loaded situation.In addition, simulate signal circuit for detecting 50 can provide a detection signal S to microprocessor 30 load state of detecting emulation USB device 20, after microprocessor 30 receives the load result that emulation USB device 20 transmitted, after can making comparisons with the load result of emulation USB device 20, export modulation signal T again.

Load control unit 40 is electrically connected on microprocessor 30, in order to receive the modulation signal T that microprocessor 30 is transmitted, to promote the load of emulation USB device 20, test the load limit of usb host end 70 to be measured by this, demonstrate the electric current and voltage load state of described usb host end 70 to be measured again via display device 60.In the utility model, load control unit 40 can be an optical relay (Photo Relay).

In addition, the utility model USB Weight detector 10 also comprises key (Start) 12 at the beginning, be electrically connected on microprocessor 30, in order to provide a user to start described USB Weight detector 10, an and reset button (Reset) 14, be electrically connected on microprocessor 30, in order to when the user when detecting described usb host end to be measured 70 unusual conditions take place, can carry out reset action with recoil state of cancellation.

To illustrate that below described USB Weight detector 10 detects the principle of operation of described usb host end 70 to be measured.Please see figures.1.and.2 simultaneously.Fig. 2 is the process flow diagram that the utility model USB Weight detector 10 detects the maximum load of described usb host end 70 to be measured.At first, microprocessor 30 can provide an initial load test value to load control unit 40 (step 102), with the load value of detection simulation USB device 20.Because the pressure drop and the loading range of the definition USB of USB association device must be tested under positive and negative 250mv and 10K0hm/500mA load environment, test so the current loading of 10K 0hm/500mA is adopted in initial load of the present utility model.

Then, microprocessor 30 is after receiving the detection signal S that load result (step 104) that emulation USB device 20 transmitted and simulate signal circuit for detecting 50 transmitted (step 106), can increase predetermined current values newly in emulation USB device 20 by output modulation signal T order load control unit 40, to judge whether emulation USB device 20 surpasses its maximum current load (step 108), if detection simulation USB device 20 does not surpass then repeating step 102 to 108 of maximum current load as yet, and in step 108, bestow current loading greater than this predetermined current value.If surpassed maximum current load to detect emulation USB device 20, then need to judge whether that through the internal logic computing of microprocessor 30 test is by (step 110), if microprocessor 30 is judged as yet not test and is passed through, then by the logical operation of the built-in divider 32 of microprocessor 30, execution in step 110 again after half of the current loading that the output of order load control unit 40 is above-mentioned tested to emulation USB device 20 (steps 112), for example: the current loading of bestowing originally is 500mA, do not test till microprocessor 30 judges that test is passed through if test, so can obtain the maximum current load of usb host end 70 to be measured by then bestowing 250mA again; If judge that through microprocessor 30 test finishes, then demonstrates the current/voltage value (step 114) of the maximum load of usb host end 70 to be measured by display device 60.

Compared to prior art, USB Weight detector 10 of the present utility model can be reached following effect:

1, compatible high, do not need extra driver: on any interface that USB port arranged, and do not need install driver to carry out to detect action;

2, it is excessive and influence the problem of system to improve the USB load ahead of time: use notion to go to inspect USB working load situation with the user, the problem that can learn product reduces the client demand, promotes product quality and reduce cost recovery to solve ahead of time on the design phase;

3, simple to operate, detect fast: utilize USB plug and play (Plug and Play) function in the design, detect Vcc/Gnd load voltage situation, and utilize the operating state of D+/D-judgement USB device, can measure the maximum load of USB to be measured apace.

Though this novel previous embodiment discloses as above, so it is not in order to limit the utility model protection domain.In not breaking away from spirit and scope of the present utility model, change of being done and retouching all belong within the scope of patent protection of the present utility model.

Claims

1. a USB (universal serial bus) Weight detector in order to detect the maximum permissible load of a USB host end to be measured, is characterized in that, this USB Weight detector comprises:

One emulation USB device, it has two power leads and binary signal line, to be connected with this usb host end to be measured;

One microprocessor is electrically connected this emulation USB device, and has the two pin positions corresponding with two power leads of this emulation USB device;

One simulate signal circuit for detecting is electrically connected this emulation USB device, and has the two pin positions corresponding with the binary signal line of this emulation USB device; And

One load control unit, electricity connect this microprocessor, in order to receive the modulation signal that this microprocessor transmits and increase this maximum permissible load that is loaded to this USB to be measured of emulation USB device.

2. USB (universal serial bus) Weight detector according to claim 1 is characterized in that: this USB Weight detector also comprises a display device, is electrically connected on this microprocessor, to show this maximum permissible load of this USB to be measured.

3. USB (universal serial bus) Weight detector according to claim 1 is characterized in that: this maximum permissible load is a current value.

4. USB (universal serial bus) Weight detector according to claim 1 is characterized in that: this microprocessor is a single-chip processor.

5. USB (universal serial bus) Weight detector according to claim 1 is characterized in that: this load control unit is an optical relay.

6. USB (universal serial bus) Weight detector according to claim 1 is characterized in that: this microprocessor also comprises a divider, so that tendency to develop to this modulation signal of this load control unit is done the dichotomy logical operation.

7. USB (universal serial bus) Weight detector according to claim 1 is characterized in that: this USB Weight detector also comprises key at the beginning, is electrically connected on this microprocessor, in order to start this USB Weight detector.

8. USB (universal serial bus) Weight detector according to claim 1 is characterized in that: this USB Weight detector also comprises a reset button, is electrically connected on this microprocessor, in order to replacement and the recoil state action of carrying out this USB Weight detector.