CN1220943C - Universal serial bus (USB) connection detecting circuit system and its operation method - Google Patents
Universal serial bus (USB) connection detecting circuit system and its operation method Download PDFInfo
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- CN1220943C CN1220943C CN 01136149 CN01136149A CN1220943C CN 1220943 C CN1220943 C CN 1220943C CN 01136149 CN01136149 CN 01136149 CN 01136149 A CN01136149 A CN 01136149A CN 1220943 C CN1220943 C CN 1220943C
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Abstract
The present invention relates to a USB connecting and detecting circuit system and an operation method thereof. The circuit system comprises a conveying circuit and a detecting circuit, wherein the conveying circuit comprises a set of differential signal lines, a set of ground resistance assemblies and a set of potential resistance assemblies. The ground resistance assemblies and the potential resistance assemblies are respectively connected with the same differential signal lines through switch assemblies. The conveying circuit uses a power supply supplying system to respectively receive signals which are relevant to electric current to the differential signal lines, and every signal which is relevant to the electric current contacts the ground through ground resistance. The detecting circuit is used for detecting the change of relevant signals of a power supply flowing across every differential signal line. When a device is connected with the circuit system through a USB transmission line, the differential signal line of the USB transmission line is connected with the differential signal lines of the circuit system, so the relevant signals of the power supply originally flowing across the ground resistance assemblies are changed. Consequently, by comparing differences of the relevant signals of the power supply before and after connection, the circuit system can automatically identify the pattern of a connected device.
Description
Technical field
The present invention relates to a kind of Circuits System and method of operating thereof, particularly relevant a kind of USB (universal serial bus) (Universal Serial Bus, USB) an employed connection detection circuit system and the method for operating thereof of system.
Background technology
USB (universal serial bus) (Universal Serial Bus USB) is leading firm by the man schedulers of number, at existing computer system and interfacing equipment install with expansion on the complicated problem that faced, a kind of new bus interface that is proposed.Under this system, all peripheral devices all can pass through same interface, that is one usb bus and main frame link up, and its characteristic is, all USB peripheral devices all have the function of plug and play, that is, when installing or removing this type of device, the main frame of neither need shutting down computer does not in advance need install driver separately yet again.
According to the USB specification, each USB system is mainly by three assemblies, that is usb host (Host), USB interconnection (Inter-connection) and USB device (Device) constitute.In each USB system, have only a usb host, and be made in a main frame inside usually.The kind of USB device has then comprised USB functional device and usb hub (Hub).The USB functional device is aforesaid computer interface equipment, for example: keyboard, mouse and printer or the like, each USB functional device is connected to a usb host by a USB interconnection; Usb hub then can be extended for single tie point a plurality of, makes a plurality of USB functional devices be able to by this hub usb bus in the connection.
Seeing also Fig. 1, is the connected mode synoptic diagram of USB system shown in the figure.By among the figure as can be known, the mode of connection that a USB system is extended downwards by a usb host 10 beginning has a starlike hierarchical structure.The Root Hub 11 (Root Hub) that is positioned at usb host 10 bottoms has two tie points 12,13, in order to connect a USB functional device 15 or usb hub 14.Each usb hub 14 can provide a plurality of tie points, to connect a plurality of USB functional devices 15, also or, this usb hub 14 also can connect one or above usb hub 16 again, so that more a plurality of USB functional device 17 is connected this bus.Mode according to this, a usb host can be connected to 127 functional devices at most.
When a USB device is connected to a usb hub device, this usb hub device can detect a new device automatically and occur, and with its usb host device that is connected of this event notice, after a series of data transmission action, this USB device just can connect this usb bus, and beginning RESPONSE CALCULATION machine host or user's demand is exercised the built-in function of its device.In the middle of this a succession of action, a usb hub device is in order to detect the mode whether have a USB device to connect or remove, is to utilize one group of connection detection circuit system that is built in respectively in usb hub device and the USB device.
See also Fig. 2, show one group of connection detection circuit system in an existing usb hub device and the USB device among the figure.This group connection detection circuit system comprises a upper detection circuitry (Up Stream Detection Circuitry) 200 that is disposed in the usb hub device 20 and a next detection circuitry (Down StreamDetection Circuitry) 300 that is disposed in the USB device 30.
On the other hand, also have one group of differential signal line 303,304 to be connected with two differential signal lines 403,404 (D+ and D-) of USB transmission line 40 in the USB device 30, this group differential signal line 303,304 all connects the interior transmission device 305 of USB device so far.
In addition, if this USB device is a speeder (Full/High Speed Device), that is data transfer rate is the device of per second 12/480Mb, for example, printer or microphone etc. then in this high speed USB device, can dispose a current potential resistance 308 (pull-up resistor), in order to connecting the differential signal line 303 in the USB device so far, and this differential signal line 3.03 is connected to the D+ differential signal line 403 of USB transmission line 40.
If this USB device is a low speed device (Low Speed Device), that is data transfer rate is the device of per second 1.5Mb, for example, mouse and keyboard etc., then in this low speed USB device, can configuration one current potential resistance 309 (pull-up resistor), in order to connecting the differential signal line 304 in the USB device so far, and this differential signal line 304 is connected to the D-differential signal line 404 of USB transmission line 40.
No matter be speeder or low speed device, one group of differential signal line 303,304 and a current potential resistance 308 or 309 in this USB device 30 can constitute the next detection circuitry (DownStream Detection Circuitry) 300.This next detection circuitry 300 is connected with upper detection circuitry 200 by USB transmission line 40, the detection action that can finish the newly-increased of USB device or remove.
Below, the function mode of at this point organizing the connection detection circuit system is done an explanation.
At first, before USB device 30 is not connected to usb hub device 20 as yet, the differential signal line 403 in order to be connected to D+ and D-in this usb hub device 20, one group of differential signal line 203 of 404,204, all be connected to an earthing potential by stake resistance 206,207.
And when USB device 30 was connected to usb hub device 20 by USB transmission line 40,20 in usb hub device can be by the VCC power lead 401 in the USB transmission line 40, and the voltage that transmits a 5V is to USB device 30.Then, the Circuits System in the USB device 30 with the power supply that utilizes usb hub device 20 to be provided, makes its current potential resistance 308 or 309 be connected to the current potential of a 3.3V.If this USB device is a speeder, then this USB device 30 will make current potential resistance 308 be connected to the current potential of a 3.3V, and make the D+ differential signal line 403 of USB transmission line produce potential change, and connect the variation that the electric potential detector 220 of the differential signal line 203 of D+ differential signal line 403 so far will detect this current potential in the usb hub device 20, so usb hub device 20 just can detect a speeder and connect bus so far.In addition, if this USB device is a low speed device, then this USB device 30 will make current potential resistance 309 be connected to the current potential of a 3.3V, and make the D-differential signal line 404 of USB transmission line produce potential change, and connect the variation that the electric potential detector 220 of the differential signal line 204 of D-differential signal line 404 so far will detect this current potential in the usb hub device 20, so usb hub device 20 just can detect a low speed device and connect bus so far.
Otherwise if originally connect a USB device 30 of usb hub device 20 so far, when bus removed since then, usb hub device 20 also can utilize this connection detection circuit system to detect the variation of current potential, and then learnt the action that removes of this device.
The above is an existing usb hub device (or a usb host), with the connection detection circuit system in the USB device.The shortcoming of this existing connection detection circuit system is that this Circuits System is to design according to standard USB specification, that is, be positioned at the device at these connection detection circuit system two ends, must keep a master slave relation, to meet the starlike hierarchical structure of usb bus.So under this Circuits System, a USB functional device can only be connected with a usb hub device or a usb host device, is connected to another USB functional device and can't directly go.
Summary of the invention
In order to overcome the deficiencies in the prior art, the purpose of this invention is to provide a kind of universal serial bus (USB) connection detecting circuit system, make a USB device be connected to an arbitrary USB device or a usb host.
Another object of the present invention provides a kind of method of operating of universal serial bus (USB) connection detecting circuit system, and making a USB device that comprises this Circuits System be detected the device that it connected automatically is a usb host or another USB device.
According to the present invention, this universal serial bus (USB) connection detecting circuit system is implemented on a USB device main frame, in order to be connected to a USB interface, and be connected with a usb host or a USB device by this USB interface, this system comprises a transfer circuit and a testing circuit, wherein, this transfer circuit is in order to receiving one first power supply coherent signal from a power system, and testing circuit is then in order to detect the variation of this first power supply coherent signal.Transfer circuit comprises one first differential signal line, one first stake resistance assembly and one first switch module, wherein, the first power supply coherent signal, first differential signal line of flowing through, and pass through the first stake resistance assembly and ground connection, and first switch module, then be disposed between first differential signal line and the stake resistance assembly, in order to switch the change-over switch of first differential signal line and the first stake resistance inter-module.
This transfer circuit also comprises one first power lead and a second switch assembly, and one first current potential resistor assembly and one the 3rd switch module, wherein, first power lead is a power lead that is sent to the USB transmission line in order to the second source coherent signal that this transfer circuit is received from a power system, and connects power system so far by the second switch assembly; And the first current potential resistor assembly is connected to first differential signal line by the 3rd switch module.
The testing circuit of this Circuits System comprises a timer, and this timer can be in order to calculate a time section.
In addition, this Circuits System also can comprise one first power system with as the power system that a plurality of power supply coherent signals are provided.
According to the present invention, the present invention also provides a kind of method of operating of universal serial bus (USB) connection detecting circuit system, comprises the following step: receive one first power supply coherent signal from a power system; Make this first power supply coherent signal pass through a stake resistance assembly and ground connection; And when a device connects on the lead that the first power supply coherent signal so far flows through, detect the variation of this first power supply coherent signal, wherein, this device connects Circuits System so far with a USB transmission line, and connects lead so far with a differential signal line of this USB transmission line.
In addition, this method of operating also comprises: receive a second source coherent signal from a power system, and this power lead that second source coherent signal is comprised to the USB transmission line is provided, wherein, this step is that the differential signal line at the USB transmission line connects so far before the Circuits System; And the variation of the detected first power supply coherent signal of foundation, whether decision stops to receive first coherent signal and second source coherent signal from power system.Wherein, when stopping after power system receives the first power supply coherent signal and second source coherent signal, if in a time section, this Circuits System then utilizes this 3rd power supply coherent signal to provide the differential signal line of one the 4th power supply coherent signal to the USB transmission line by a current potential resistor assembly when receiving one the 3rd power supply coherent signal on the power lead that the USB transmission line that is connected is comprised.Otherwise, if behind a time section, on the power lead of the USB transmission line that is connected, do not receive one the 3rd power supply coherent signal yet, then this Circuits System will receive the first power supply coherent signal and two power supply coherent signals from power system again, and make the first power supply coherent signal pass through the first stake resistance assembly and ground connection again, and provide the power lead of second source coherent signal to the USB transmission line.
By above-mentioned function mode, device main frame of the present invention (devicehost) device can pick out the device kenel that it connected clearly, and switch to a device pattern or a host mode voluntarily to respond the device that it is connected, to carry out data transmission work to each other smoothly.
Description of drawings
The present invention is described in detail below in conjunction with drawings and Examples:
Fig. 1 is the connected mode synoptic diagram of USB system;
Fig. 2 is an existing USB connection detection circuit system schematic;
Fig. 3 is the connection detection circuit system schematic of the present invention the 1st embodiment;
Fig. 4 a is a device and the connection diagram of one usb host/hub device that comprises the connection detection circuit system of the present invention the 2nd embodiment;
Fig. 4 b is a device and the connection diagram of a USB device that comprises the connection detection circuit system of the present invention the 2nd embodiment;
Fig. 5 a is a device and the connection diagram of one usb host/hub device that comprises the connection detection circuit system of the present invention the 3rd embodiment;
Fig. 5 b is a device and the connection diagram of one usb host/hub device that comprises the connection detection circuit system of the present invention the 3rd embodiment;
Fig. 6 is the detection flow chart of steps of the connection detection circuit system of the present invention the 2nd embodiment.
Symbol description among the figure:
10 usb hosts
11 Root Hubs
12 tie points
13 tie points
14 usb hubs
15 USB functional devices
16 usb hubs
17 USB functional devices
20 usb hosts/hub device
200 upper detection circuitry
203 differential signal lines
204 differential signal lines
205 USB transmission devices
206 stake resistances
207 stake resistances
30 USB devices
300 the next detection circuitry
303 differential signal lines
304 differential signal lines
305 USB transmission devices
308 current potential resistance
309 current potential resistance
40 USB transmission lines
401 VCC power leads
402 GND power leads
403 D+ differential signal lines
404 D-differential signal lines
50 USB device main frames
503 differential signal lines
504 differential signal lines
506 stake resistances
507 stake resistances
508 current potential resistance
509 current potential resistance
509 current potential resistance
510 power systems
511 hand switch component groups
60 USB device main frames
600 connection detection circuit systems
603 differential signal lines
604 differential signal lines
605 USB transmission receivers
606 stake resistances
607 stake resistances
608 current potential resistance
609 current potential resistance
610 power systems
611 power leads
612 ground wires
620 current detection circuit systems
70 USB device main frames
700 connection detection circuit systems
701 upper resistance
702 upper resistance
703 differential signal lines
704 differential signal lines
705 USB transmission receivers
706 stake resistances
707 stake resistances
710 power systems
711 power leads
712 ground wires
720 voltage detecting circuit systems
Embodiment
Below, do a detailed explanation with regard to proposed by the invention several in order to method and the embodiment of reaching aforementioned purpose.
" manual switchover pattern (Manual Switch Mode) "
Referring to Fig. 3, shown in the figure for the connection detection circuit system of the present invention the 1st embodiment.This connection detection circuit system 500 has one group of differential signal line 503,504, one group of current potential resistance 508,509, a winding earth resistance 506,507, a power system 510, and a manual switch module group 511.Wherein, differential signal line 503 is in order to be connected to the D+ differential signal line 403 of USB transmission line 40, and differential signal line 504 is then in order to be connected to the D-differential signal line 404 of USB transmission line 40.The connection detection circuit system of this embodiment is the Circuits System of a manual switch mode (Manual Switch Mode).
When a USB device main frame (devicehost) 50 that comprises this connection detection circuit system 500 desired to be connected to a usb host or usb hub device, the user can utilize a manual switch module group 511 that this USB device 50 is switched to one " device pattern (Device-Mode) ".Under this device pattern, if this USB device main frame (devicehost) 50 is a speeder, a current potential resistance 508 that then is disposed in this connection detection circuit system 500 will be connected to differential signal line 503, and another current potential resistance 509, a winding earth resistance 503,504 and 510 of power systems all are in the state that opens circuit; If this USB device main frame (devicehost) 50 is a low speed device, a current potential resistance 509 that then is disposed in this connection detection circuit system 500 will be connected to differential signal line 504, and another current potential resistance 508, a winding earth resistance 503,504 and 510 of power systems all are in the state that opens circuit.
When this USB device main frame (devicehost) 50 connects a last usb host or usb hub device, usb host that it connected or usb hub device will be by USB transmission lines 40, supply with the voltage of this USB device main frame (devicehost) 50 1 5V, its follow-up detection action is then all identical with aforesaid USB device 30.
If when this USB device main frame (devicehost) 50 desired to be connected to another USB functional device, the user can utilize hand switch component groups 511 equally, and this USB device main frame (devicehost) 50 is switched to one " host mode (Host-Mode) ".Under this host mode, be disposed at the winding earth resistance 506 in this connection detection circuit system 500,507 will be connected to differential signal line 503 respectively, 504, one power system 510 also will connect the interior power lead of USB device main frame (devicehost) so far, and another 508,509 of group current potential resistance will be in the state that opens circuit.Utilize this connection detection circuit system 500, when another USB functional device is gone up in these USB device main frame (devicehost) 50 connections, the intrasystem power system 510 of this connection detection circuit can be supplied with the voltage of another USB functional device 5V by a USB transmission line 40, this USB functional device then can be according to general USB Device Testing mode, look the kind (high speed or low speed) of its device, to be connected to D+ or D-differential signal line 403,404 current potential resistance is connected to the voltage of a 3.3V, make D+ or D-differential signal line 403,404 produce potential change.At this moment, this device main frame (devicehost) just can be differentiated the kind of this functional device according to this potential difference (PD), and finishes joint detection action between the two.In above-mentioned situation, this USB device main frame (devicehost) utilizes this connection detection circuit system 500, is connected with another USB functional device in the mode of emulation one usb host or usb hub device.So, utilize this connection detection circuit system, this USB device main frame (devicehost) can be connected with another USB functional device " master slave relation " principle with the USB standard, and and then utilize the software or the firmware of The built-in, carry out the data transmission action of the two.This measure can solve under standard USB specification, can't directly connect each other between the USB device and the problem of data transmission.
" current detecting pattern (Current-Detection Mode) "
The difference of this current detecting pattern and previous manual switch mode is, the connection detection circuit system of this current detecting pattern, can utilize the variation of a current value, detecting the device that it connected voluntarily is a usb host (or a usb hub device) or a USB functional device.The user will not need to utilize aforesaid manual mode again, adjust the state of the device main frame (devicehost) of the current detection circuit system that comprises this current detecting pattern.
See also Fig. 4 a and Fig. 4 b, show the connection detection circuit system 600 of the present invention the 2nd embodiment among the figure.This connection detection circuit system 600 comprises one group of differential signal line 603,604, a power lead 611, a ground wire 612, a winding earth resistance 606,607, one group of current potential resistance 608,609, a power system 610 and current detection circuit system 620 (Current-Detection Circuitry).Wherein, differential signal line 603,604 is in order to being connected to the D+ of USB transmission line, D-differential signal line 403,404, and a winding earth resistance 606,607 and one group of 608,609 of current potential resistance are connected to differential signal line 603,604 by a switch module separately.In addition, in current detection circuit system 620, still comprise the design of a timer 621 (timer), the purposes of this timer 62l will be illustrated in the back again; And this Circuits System 600 can also an external power supply mode replace power system 610.
The method of this current detecting pattern is, utilize a power system 610 to supply with a current source respectively to differential signal line 603,604, when the device main frame (devicehost) 60 that comprises this connection detection circuit system 600 is not connected with any device, electric current I p, Im will flow through stake resistance 606,607 and ground connection respectively.
Seeing also Fig. 4 a, is to comprise device main frame (devicehost) 60 of this connection detection circuit system 600 and the connection diagram of one usb host/hub device 20 shown in the figure.When this device main frame (devicehost) 60 is connected to a usb host 20 (or a usb hub device), originally flow through stake resistance 606 and the electric current I p of ground connection are with stake resistance 606 in this device main frame (devicehost) of flowing through respectively and the stake resistance 206 that is positioned at usb host 20; Similarly, originally flow through stake resistance 607 and the electric current I m of ground connection are also with stake resistance 607 in this device main frame (devicehost) of flowing through respectively and the stake resistance 207 that is positioned at usb host 20.So, the electric current I p of the stake resistance 606,607 of supposing originally to flow through, Im is all I, and the resistance of stake resistance 606,607 is all Rp, and the resistance that is positioned at the stake resistance 206,207 of usb host is Rpd.Then when this device main frame (devicehost) connects a last usb host, the electric current I p of this two stake resistance of flowing through, the current value of Im, can formula (1) represent:
Ip=Im=I*Rpd/ (Rpd+Rp)---------Shi (1)
By the flow through current value of stake resistance 606,607 of measurement, it is a usb host that this device main frame (devicehost) can pick out its device that connects, and switches to a device pattern voluntarily.At this moment, stake resistance 607,608 will be cut off with the connection of differential signal line 603,604, and originally be that the current potential resistance 608,609 of off state will be connected to differential signal line 603,604.
Referring to Fig. 4 b, install the connection diagram of a main frame (devicehost) 60 and a USB device 80 shown in the figure for this reason.As previously mentioned, if this USB device 30 is a speeder, then will has a current potential resistance 308 in this device and be connected to D+ differential signal line 403; If this USB device 30 is a low speed device, then will has a current potential resistance 309 in this device and be connected to D-differential signal line 404.When this device main frame 60 (devicehost) is connected to a high speed USB device, suppose that the resistance of the current potential resistance 308 in this device is R
H, the voltage that puts on this current potential resistance is V
H, the current value I p of the stake resistance 606 of then flowing through this moment can formula (2) represent:
Ip＝(V
H+I*R
H)/(R
H+Rp)-------- (2)
And when this device main frame 60 (devicehost) is connected to a low speed USB device, suppose that the resistance of the current potential resistance 309 in this device is R
L, the voltage that puts on this current potential resistance is V
L, the current value I m of the stake resistance 607 of then flowing through this moment can formula (3) represent:
Im＝(V
L+I*R
L)/(R
L+Rp)--------(3)
By the flow through current value of stake resistance 606,607 of measurement, it is a high speed USB device or a low speed USB device that this device main frame (devicehost) can pick out its device that connects, and switches to a host mode voluntarily.At this moment, the current potential resistance 608,609 in this Circuits System will be kept its original off state.
So, the connection detection circuit system of a current detecting pattern thus, it is a usb host that this device main frame (devicehost) can detect the device that it connected voluntarily, or another USB device.
" voltage detecting pattern (Voltage Detection Mode) "
This voltage detecting pattern is identical with aforesaid current detecting pattern, the neither need of user are in the mode of manual switchover, adjust the state of this device main frame (devicehost) in advance, and its difference is, this voltage detecting pattern is to utilize a voltage detecting system, and the variation that detects magnitude of voltage comes its device kenel that is connected of identification.
Referring to Fig. 5 a and Fig. 5 b, show the connection detection circuit system of the 3rd embodiment of the present invention among the figure.The connection detection circuit system 700 of this voltage detecting pattern comprises one group of differential signal line 703,704, a power lead 711, a ground wire 712, a winding earth resistance 706,707, one group of current potential resistance 708,709, one group of upper resistance 701,702 (Up Stream Resistor), a power system 710 and a voltage detecting circuit system 720 (Voltage-DetectionCircuitry).Wherein, differential signal line 703,704 is in order to be connected to the D+ of USB transmission line 40, D-differential signal line 403,404.Stake resistance 706, current potential resistance 708 and upper resistance 701 are to be connected to differential signal line 703 by a switch module separately; And stake resistance 707, current potential resistance 709 and upper resistance 702 also are connected to differential signal line 704 by a switch module separately.In addition, in the voltage detecting circuit system, the design of a timer 721 is arranged still, the purposes of this timer 721 will be illustrated in the back again.
Different with aforesaid current detecting pattern is that this power system 710 will apply a voltage V respectively to being connected to the upper resistance 701,702 of differential signal line.Therefore, when this installs main frame (devicehost) when not being connected to any device as yet, suppose upper resistance 701,702 resistance is Rs, and the resistance of stake resistance 706,707 is Rp, the intrasystem voltage detecting system 720 of this joint detection, can formula (4) represent in differential signal line 703,704 detected magnitude of voltage Vs:
Vs＝V*Rp/(Rp+Rs)------------?(4)
Referring to Fig. 5 a, show the connection diagram of this a device main frame 70 (devicehost) and a usb host 20 (or a usb hub device) among the figure.As previously mentioned, have a winding earth resistance 206,207 in this usb host 20 and be connected to D+ differential signal line 403 and D-differential signal line 404 by differential signal line 203,204 respectively.If the stake resistance 206 in this usb host 20,207 resistance is all Rpd, then when in this device main frame 70 (devicehost) connections during this usb host 20, voltage detecting system 720 can formula (5) be represented in differential signal line 703,704 detected magnitude of voltage Vh:
Vh＝V*(Rpd*Rp)/(Rpd*Rp+Rpd*Rs+Rp*Rs)------(5)
By the difference between comparing voltage value Vs and Vh, it is a usb host (or a usb hub device) that this device main frame 70 (devicehost) can pick out its device that connects, and switches to a device pattern voluntarily.At this moment, stake resistance 707,708 will be cut off with the connection of differential signal line 703,704, and originally be that the current potential resistance 708,709 of off state will be connected to differential signal line 703,704.
Referring to Fig. 5 b, show the connection diagram of this a device main frame 70 (devicehost) and a USB device 30 among the figure.When this device main frame 70 (devicehost) is connected to a high speed USB device, suppose that the resistance of the current potential resistance 308 in this device is R
H, the voltage that puts on the current source of this current potential resistance is V
H, then voltage detecting system 720 can formula (6) expression in differential signal line 703 detected magnitude of voltage Vd
Vd＝(V*(Rp*R
H)/(Rp*R
H+Rp*Rs+R
H*Rs))+
(V
H*(Rp*Rs)/(Rp*Rs+Rp*R
H+Rs*R
H))------(6)
When if this device main frame 70 (devicehost) is connected to a low speed USB device, suppose that the resistance of the current potential resistance 309 in this device is R
L, the voltage that puts on the current source of this current potential resistance is V
L, then voltage detecting system 720 can formula (7) be represented in differential signal line 704 detected magnitude of voltage Ve:
Ve＝(V*(Rp*R
L)/(Rp*R
L+Rp*Rs+R
L*Rs))+
(V
L*(Rp*Rs)/(Rp*Rs+Rp*R
L+Rs*R
L))------(7)
By the difference between comparing voltage value Vs and Vd or Ve, it is a high speed USB device or a low speed USB device that this device main frame 70 (devicehost) can pick out its device that connects, and switches to a host mode voluntarily.At this moment, current potential resistance 708,709 will be kept its original off state.
The method of three kinds of circuit design mentioned above is in order to solve between the existing USB device, can't directly connect each other and the problem of signal transmission.A kind of device main frame (devicehost) device that comprises above-mentioned connection detection circuit system has been proposed, this device can be by aforesaid " manual switchover pattern ", " current detecting pattern " and methods such as " voltage detecting patterns ", detect the device kenel that it connects, and select to respond usb host or the USB device that is connected with a device pattern or a host mode.In the manual switchover pattern, because this device main frame (devicehost) device is to be adjusted into a device pattern or a host mode by manual mode, so when two device main frames (devicehost) when device is connected, mode that can manual switchover decides master slave relation to each other.And in current detecting pattern and voltage detecting pattern, in this device main frame (devicehost) device, can dispose one group of logical circuit again,, how determine the problem of master slave relation to each other in order to solve two device main frames (devicehost) when device is connected to each other.Below, will be example with device main frame (devicehost) device of current detecting pattern, cooperate Fig. 6 to do a detailed explanation.
Referring to Fig. 6, this figure is that device main frame (devicehost) device is a usb host, a USB device or device main frame (devicehost) Device Testing flow chart of steps in order to detect its device that connects.
At first, when arbitrary device is gone up in this device main frame (devicehost) device connection (step 601), as previously mentioned, its inner current detection circuit system can detect the variation (step 602) that is connected to the current value on D+ or the D-differential signal line.If this moment, detected electric current was changed to the current value shown in formula (2) or the formula (3) by " I " value originally, then can to pick out the device that is connected be a high speed USB device or low speed USB device to this device main frame (devicehost) device, and switch to a host mode (step 603) voluntarily.
Yet, if the device that this device main frame (devicehost) device is connected is a usb host or another device main frame (devicehost) device, because the two all has a power system and the winding earth resistance of supply 5V, therefore, the inner detected current value of current detection circuit system of this device changes, all will be identical with formula (1).So, when the current detection circuit system detects this phenomenon, this device main frame (devicehost) device will cut off in its device the power system in order to supply 5V voltage in advance, and be connected (step 604) of cutting off stake resistance and differential signal line.
Afterwards, this device main frame (devicehost) device will activate a timer 621 (Timer) (step 605).To set a time section (time period) at random in this timer 621, when this device main frame (devicehost) device activates this timer 621, the work that this timer 621 will begin to countdown with this time section.If receive the 5V voltage (step 606) that the other end sends in the section between this device main frame (devicehost) installs at this moment, then can to pick out its device that connects be a usb host to this device main frame (devicehost) device, and switch to a device pattern (step 607) voluntarily.
Otherwise, if when timer 621 end of countdowning, that is after surpassing the time section that sets, when this device main frame (devicehost) installs the voltage that does not also detect 5V (step 608), then this device main frame (devicehost) device will activate its power system once more, and make stake resistance be connected to (step 609) on the differential signal line once more.Afterwards, as seen from the figure, the connection detection circuit system of this device main frame (devicehost) device will repeat above-mentioned action again from detecting step 602.
Therebetween, when two device main frames (devicehost) install all when carrying out above-mentioned detection action, key in order to decision master slave relation to each other is, this two devices is determined at random by timer 621, again " mistiming " activating its power system separately and reconnect its stake resistance, that is, when wherein one the device main frame (devicehost) device activate its power system again and reconnect its stake resistance, and another device main frame (devicehost) installs when not carrying out this action as yet, again the device of activating power supply system and connection stake resistance will be regarded as a usb host device and switch to host mode (step 602 is to step 603) in testing process in advance, and another then will be regarded as a USB device and switch to a device pattern (step 606 is to step 607).
So, by above-mentioned function mode, device main frame of the present invention (devicehost) device can pick out the device kenel that it connected clearly, and switch to a device pattern or a host mode voluntarily to respond the device that it is connected, to carry out data transmission work to each other smoothly.
Though preferred embodiment of the present invention used particular form describe as before, should be appreciated that herein previous example only is a usefulness for convenience of description, and it still can do various modification and variation in not deviating from spirit of the present invention and scope.
Claims (23)
1. the method for operating of a universal serial bus (USB) connection detecting circuit system comprises the following step:
Receive one first power supply coherent signal from a power system;
Make this first power supply coherent signal pass through a stake resistance assembly and ground connection; And
When a device is connected on the lead that this first power supply coherent signal flows through, detect the variation of this first power supply coherent signal, wherein, this device is to connect Circuits System so far with a USB transmission line, and is connected to this lead with a differential signal line of this USB transmission line.
2. method according to claim 1 is characterized in that: also comprise the following step:
Receive a second source coherent signal from this power system, and the power lead of this second source coherent signal to this USB transmission line is provided, wherein, this step is before this differential signal line of this USB transmission line is connected to this lead; And
According to the variation of detected this first power supply coherent signal, whether decision stops to receive this first power supply coherent signal and this second source coherent signal from this power system.
3. method according to claim 2, it is characterized in that: when stopping after this power system receives this first power supply coherent signal and this second source coherent signal, if in a time section, when this Circuits System receives one the 3rd power supply coherent signal on this power lead of this USB transmission line, then utilize the 3rd power supply coherent signal to provide one the 4th power supply coherent signal this differential signal line to this USB transmission line by a current potential resistance.
4. method according to claim 3, it is characterized in that: if behind this time section, when this Circuits System does not receive the 3rd power supply coherent signal on this power lead of this USB transmission line, then receive this first power supply coherent signal and this second source coherent signal from this power system again, and make this first power supply coherent signal pass through this stake resistance assembly and ground connection again, and provide this second source coherent signal this power lead to this USB transmission line.
5. method according to claim 4 is characterized in that: this first power supply coherent signal is an electric current or a voltage.
6. method according to claim 4 is characterized in that: this second source coherent signal is an electric current or a voltage.
7. method according to claim 4 is characterized in that: the 3rd power supply coherent signal is an electric current or a voltage.
8. a universal serial bus (USB) connection detecting circuit system is implemented on a USB device main frame, in order to being connected to a USB interface, and is connected with a usb host or a USB device by this USB interface, and this system comprises:
One transfer circuit comprises one first power supply coherent signal at interior a plurality of power supply coherent signals in order to receive from a power system, and wherein, this transfer circuit comprises:
One first differential signal line is in order to be connected to a differential signal line of a USB transmission line;
One first stake resistance assembly, in order to be connected to this first differential signal line, wherein, flow through this first differential signal line and by this first stake resistance assembly and ground connection of this first power supply coherent signal system; And
One first switch module is in order to switch being connected of this first differential signal line and this first stake resistance assembly; And
One testing circuit is in order to detect the variation of this first power supply coherent signal.
9. Circuits System according to claim 8 is characterized in that: this transfer circuit also comprises
One first power lead is sent to a power lead of this USB transmission line in order to a second source coherent signal that this transfer circuit is received from this power system;
One second switch assembly is in order to switch being connected of this first power lead and this power system;
One first current potential resistor assembly is in order to be connected to this first differential signal line; And
One the 3rd switch module is in order to switch being connected of this first current potential resistor assembly and this first differential signal line.
10. Circuits System according to claim 9 is characterized in that: this testing circuit comprises
One timer is in order to calculate a time section.
11. Circuits System according to claim 10 is characterized in that: this Circuits System comprises
One first power system is in order to this power system as this multiple power supply coherent signal of supply.
12. according to claim 9 or 10 described Circuits System, it is characterized in that: this second source coherent signal is a voltage.
13. according to Claim 8,9 or 10 described Circuits System, it is characterized in that: this first power supply coherent signal is an electric current.
14. Circuits System according to claim 13 is characterized in that: this transfer circuit also comprises
One second differential signal line is in order to be connected to another differential signal line of this USB transmission line;
One second stake resistance assembly, in order to be connected to this second differential signal line, wherein, this transfer circuit passes through this second stake resistance and ground connection from another electric current that this power system receives;
One the 4th switch module is in order to switch being connected of this second differential signal line and this second stake resistance unit's line;
One second current potential resistor assembly is in order to be connected to this second differential signal line; And
One the 5th switch module is in order to switch being connected of this second current potential resistance and this second differential signal line.
15. according to Claim 8,9 or 10 described Circuits System, it is characterized in that: this first power supply coherent signal is a voltage.
16. Circuits System according to claim 15 is characterized in that: this transfer circuit also comprises
One first resistor assembly is disposed between this power system and this first differential signal line, and this first power supply coherent signal is put on this first resistor assembly.
17. Circuits System according to claim 16 is characterized in that: this transfer circuit also comprises
One second differential signal line is in order to be connected to another differential signal line of this USB transmission line;
One second resistor assembly is disposed between this power system and this second differential signal line, and wherein, this transfer circuit puts on this second resistor assembly from another voltage that this power system receives;
One the 3rd switch module is in order to switch being connected of this second resistor assembly and this second differential signal line;
One second stake resistance assembly is connected to this second differential signal line, and wherein, this another voltage system passes through this second stake resistance assembly and ground connection;
One the 4th switch module is in order to switch being connected of this second stake resistance assembly and this second differential signal line;
One second current potential resistor assembly is connected to this second differential signal line; And
One the 5th switch module is in order to switch being connected of this second current potential resistor assembly and this second differential signal line.
18. a Circuits System is to comprise:
One first differential signal line is in order to be connected to a differential signal line of a USB transmission line;
One first resistor assembly, the one end is connected to a power supply potential, and the other end then is connected to this first differential signal line;
One second resistor assembly, one end are connected to this first differential signal line, and the other end then is connected to earthing potential;
One first power lead is in order to connect a power lead of this USB transmission line; And
One switch module group, in order to the action of between this first resistor assembly and this second resistor assembly and this first differential signal line, switching, in addition, also in order to switch being connected of this first power lead and a power system.
19. Circuits System according to claim 18 is characterized in that: this Circuits System also comprises one first power system, in order to as this power system of being connected with this first power lead.
20. a USB peripheral unit, this device comprises:
One transfer circuit comprises one first power supply coherent signal at interior multiple power supply coherent signal in order to receive from a power system, and wherein, this transfer circuit comprises:
One first differential signal line;
One first stake resistance assembly, in order to be connected to this first differential signal line, wherein, this first power supply coherent signal is by this first differential signal line and this first stake resistance assembly and ground connection; And
One first switch module is in order to switch being connected of this first differential signal line and this first stake resistance assembly; And
One testing circuit is in order to detect the variation of this first power supply coherent signal.
21. USB peripheral unit according to claim 20 is characterized in that: this transfer circuit also comprises
One first power lead is sent to a power lead of this USB transmission line in order to a second source coherent signal that this transfer circuit is received from this power system;
One second switch assembly is in order to switch being connected of this first power lead and this power system;
One first current potential resistor assembly is in order to be connected to this first differential signal line; And
One the 3rd switch module is in order to switch being connected of this first current potential resistor assembly and this first differential signal line.
22 according to claim 20 or 21 described peripheral units, and it is characterized in that: this testing circuit also comprises a timer, in order to calculate a time section.
23. peripheral unit according to claim 22 is characterized in that: this device also comprises one first power system, in order to this power system as this multiple power supply coherent signal of supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 01136149 CN1220943C (en) | 2001-11-07 | 2001-11-07 | Universal serial bus (USB) connection detecting circuit system and its operation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 01136149 CN1220943C (en) | 2001-11-07 | 2001-11-07 | Universal serial bus (USB) connection detecting circuit system and its operation method |
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| Publication Number | Publication Date |
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| CN1417681A CN1417681A (en) | 2003-05-14 |
| CN1220943C true CN1220943C (en) | 2005-09-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 01136149 Expired - Fee Related CN1220943C (en) | 2001-11-07 | 2001-11-07 | Universal serial bus (USB) connection detecting circuit system and its operation method |
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| Country | Link |
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| CN (1) | CN1220943C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103547454A (en) * | 2012-05-09 | 2014-01-29 | 中国人民银行印制科学技术研究所 | Associated printing apparatus |
| WO2020037075A1 (en) * | 2018-08-16 | 2020-02-20 | Texas Instruments Incorporated | Adjustable embedded universal serial bus 2 low-impedance driving duration |
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|---|---|---|---|---|
| CN1324494C (en) * | 2003-07-02 | 2007-07-04 | 华硕电脑股份有限公司 | Hitch device of universal serial bus (USB) |
| CN100409149C (en) * | 2005-10-28 | 2008-08-06 | 环达电脑(上海)有限公司 | Connection channel device between PC machine and built-in equipment GPS module and communication method |
| CN101420480B (en) * | 2007-10-25 | 2011-02-09 | 宏达国际电子股份有限公司 | Detection circuit and related detection method |
| US8341303B2 (en) | 2008-06-30 | 2012-12-25 | Intel Corporation | Asymmetrical universal serial bus communications |
| CN101937039B (en) * | 2010-05-21 | 2015-01-28 | 天地融科技股份有限公司 | Connecting detection method |
| CN102298101B (en) * | 2010-06-24 | 2013-04-24 | 神基科技股份有限公司 | Detection device for bus connection |
| CN102385018B (en) * | 2010-09-06 | 2016-06-01 | 国网山东省电力公司济宁供电公司 | External equipment connection sensing circuit |
| CN103473208B (en) | 2013-04-12 | 2016-10-12 | 威盛电子股份有限公司 | Transmission system |
| CN106033400B (en) * | 2015-03-18 | 2019-04-05 | 瑞昱半导体股份有限公司 | Universal serial bus cable species detection device and method |
| US10224727B2 (en) * | 2015-06-30 | 2019-03-05 | Dong-Sheng Li | Multi-functional hub integrated with AC power supply |
| CN107907779B (en) * | 2017-11-03 | 2020-02-18 | 中车青岛四方机车车辆股份有限公司 | Handheld cable conduction testing device, system and method for railway vehicle |
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2001
- 2001-11-07 CN CN 01136149 patent/CN1220943C/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103547454A (en) * | 2012-05-09 | 2014-01-29 | 中国人民银行印制科学技术研究所 | Associated printing apparatus |
| CN103547454B (en) * | 2012-05-09 | 2016-06-01 | 中国人民银行印制科学技术研究所 | A kind of associating printing device |
| WO2020037075A1 (en) * | 2018-08-16 | 2020-02-20 | Texas Instruments Incorporated | Adjustable embedded universal serial bus 2 low-impedance driving duration |
| CN112867996A (en) * | 2018-08-16 | 2021-05-28 | 德克萨斯仪器股份有限公司 | Adjustable embedded universal serial bus 2 low impedance drive duration |
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|---|---|
| CN1417681A (en) | 2003-05-14 |
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