CN209690902U - A kind of USB interface of printer sharing - Google Patents

Abstract

The utility model discloses a kind of USB interface of printer sharing, is applied to printer sharing field, and circuit structure includes: MCU chip and USB control chip；Wherein, the data/address bus that USB controls chip is connected with the P0 of MCU chip mouth；The read-write strobe pin that USB controls chip is corresponding with exterior read-write the strobe pin P3.6 and P3.7 of MCU chip connected；The interrupt requests pin INT_N of USB control chip is connected with the external interrupt pin INT0 of MCU chip；USB controls the chip selection signal pin ground connection of chip, and address bit pin A0 is connected with the P3.5 pin of MCU chip；The DMA response pin DMACK_N of USB control chip is also connected with interrupt requests pin INT_N, triggers for low level.Utility model has the advantages that the usb data of printer sharing can be made to connect with good stability and versatility.

Description

A kind of USB interface of printer sharing

Technical field

The utility model relates to printer sharing field more particularly to a kind of USB interfaces of printer sharing.

Background technique

Printer sharing is called self-service printer, is a kind of automatic printing equipment suitable for public place, is especially suitable for In campus environment.Since student often has the printing demand of the papers material such as operation, data, paper, and StoreFront is printed by environment It is limited with property, often will cause crowded queuing, price is unknown, and the public USB flash disk that print shop provides has the puzzlement such as Viral risks Situation.It can be seen that the usage experience of student can be significantly improved using printer sharing, meet the literary print demand of student, has There is biggish commercial value.

Further, using printer sharing print when, user often use such as USB flash disk, mobile phone external equipment as The storage medium of demand mimeograph documents, that is, user is to carry out data by the USB interface and printer sharing of printer sharing to lead to Letter connection.It can be seen that the USB interface design of printer sharing directly affects the commercial result of printer sharing；But by Different in the model brand of the external devices such as USB flash disk, the mobile phone of user, USB interface can not after often having user equipment to be inserted into USB interface The case where connection and identification, it is therefore desirable to General design be carried out to the USB interface of printer sharing, to promote USB interface Data transmission stability and versatility.

Utility model content

In order to further enhance the message transmission rate and discrimination of the USB interface of printer sharing, the utility model is mentioned For a kind of USB interface of printer sharing, which also has the advantages that free drive moves plug and play, can effectively promote use Family satisfaction.

The concrete scheme of the utility model is as follows:

A kind of USB interface of printer sharing, which is characterized in that the circuit structure of USB interface include: MCU chip U1 and USB controls chip U2；Wherein, the data/address bus of chip U2 is connected with the P0 of chip U1 mouth；The read-write strobe pin of chip U2 with Exterior read-write strobe pin P3.6 and the P3.7 correspondence of chip U1 is connected；Interrupt requests the pin INT_N's and U1 of chip U2 is outer Portion interrupt pin INT0 is connected；The chip selection signal pin of chip U2 is grounded, and the P3.5 of address bit pin A0 and chip U1 control foot It is connected；The DMA response pin DMACK_N of chip U2 is also connected with interrupt requests pin INT_N, triggers for low level.

Further, the circuit structure of the USB interface further includes USB interface, and the USB interface has operating voltage Four VCC, data D-, data D+ and ground connection pins, wherein the data D- and data D+ is for the data between the U2 Communication, is additionally provided with LED light D1, the D1 is used to indicate the USB and connects between the VCC pin and GND pin of the USB interface The connection status of mouth.

Further, LED light D2, institute are additionally provided between the GL_N pin of the U2 and the VCC pin of the USB interface State the communications status that D2 is used to indicate the USB interface.

Further, the pull-up resistor of 1.5K Ω is additionally provided on the data D- of the USB interface and data D+ pin.

Further, the operating voltage of described U1, U2 and USB interface is 5V.

Further, the U1 is connected with crystal oscillator Y1, and the oscillation frequency of the Y1 is 11.0952MHz；The U2 and crystal oscillator Y2 is connected, and the oscillation frequency of the Y2 is 6MHz.

Further, the U1 is STC12C5A60S2 chip, and the U2 is PDIUSBD12 chip.

After adopting the above scheme, the beneficial effects of the utility model are as follows:

1, the USB interface of the utility model is configured with two LED light for indicating respectively connection status and communications status, energy User is enough set to know the working condition of printer sharing USB interface.

2, the USB interface of the utility model has used MCU chip STC12C5A60S2 and USB to control chip PDIUSBD12, Circuit structure integrated level is high, low in cost, convenient for promoting and utilizing.

3, the USB interface of the utility model is not necessarily to write complicated USB device driver, improves the USB of printer sharing Discrimination, it is user-friendly.

Detailed description of the invention

Fig. 1 is the USB interface schematic diagram of the utility model.

Specific embodiment

It is practical new below in conjunction with this to keep the objectives, technical solutions, and advantages of the embodiments of the present invention clearer Attached drawing in type embodiment, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that is retouched The embodiment stated is the utility model a part of the embodiment, instead of all the embodiments.Usually here in attached drawing description and The component of the utility model embodiment shown can be arranged and be designed with a variety of different configurations.

Therefore, requirement is not intended to limit to the detailed description of the embodiments of the present invention provided in the accompanying drawings below The scope of the utility model of protection, but it is merely representative of the selected embodiment of the utility model.Based in the utility model Embodiment, every other embodiment obtained by those of ordinary skill in the art without making creative efforts, all Belong to the range of the utility model protection.

It should also be noted that similar label and letter indicate similar terms in following attached drawing, therefore, once a certain Xiang Yi It is defined in a attached drawing, does not then need that it is further defined and explained in subsequent attached drawing.With reference to the accompanying drawing and Embodiment elaborates to the utility model.

It is to be appreciated that data communication can not be directly carried out between USB interface and the MCU of single-chip microcontroller type, this is because Single-chip microcontroller uses clock cycle level bus (Time live to long, TTL) as the host computer of USB interface, and USB interface agreement is slower with respect to TTL, can not work under the same clock cycle, generally can be using cores such as PL2303, CH341 Piece realizes the transfer protocol interaction between USB interface and single-chip microcontroller.But for printer sharing, towards be big everybody Group uses, and USB interface is often connect with the circumscribed USB equipment of different brands and standard, therefore is easy to appear driving and does not prop up The case where holding influences the normal use of user.And the USB interface of the utility model, it is desired based on USB control chip U2 and single-chip microcontroller The step of parallel port communication between MCU chip U1, driver simplified by hardware circuit, enhancing USB interface lead to With property and ease for use.

A kind of USB interface of printer sharing as shown in Figure 1, circuit structure include: MCU chip U1 and USB control Chip U2.Specifically, the data/address bus of chip U2 is connected with the P0 of chip U1 mouth, and the P0 mouth of chip U1 is one group 8 herein Parallel interface, corresponding, the data/address bus of chip U2 refers to parallel bus herein.It is to be appreciated that the advantage of parallel interface It is under identical frequency compared to serial mode communication speed faster.Further, the read-write strobe pin and chip of chip U2 Exterior read-write strobe pin P3.6 and the P3.7 correspondence of U1 is connected, to realize the communication party of full duplex between chip U1 and chip U2 Formula.The external interrupt pin INT0 of the interrupt requests pin INT_N and chip U1 of chip U2 are connected, and the interruption of chip U2 is drawn herein Foot is effective in low level.The chip selection signal CS_N pin of chip U2 is grounded, and the P3.5 of address bit pin A0 and chip U1 are controlled Foot is connected, and specifically, indicates that chip U1 sends command instruction when address bit pin A0 is high level, when address bit pin A0 is Indicate that chip U1 sends data command when low level.The direct memory access (Direct Memory Access, DMA) of chip U2 Request pin DMREQ hanging.The DMA response pin DMACK_N of chip U2 is connected with interrupt requests pin INT_N, for low Level triggers.The address latch of chip U2 allows signal (Address Latch Enable, ALE) pin to be grounded, and indicates chip U2 closes address information during working and latches.

It further, further include USB interface in usb circuit structure, USB interface has Vbus, data D-, data D+ With four pins of ground connection, wherein data D- and data D+ is used for the data communication between USB control chip.In USB interface LED lamp D1 is additionally provided between VCC pin and GND pin, LED light D1 is used to indicate the connection status of USB interface herein.Specifically Ground illustrates that USB interface can be with normal communication when LED light D1 is bright.

It is to be appreciated that USB device generally has, there are two types of powering mode, bus-powered and self-powereds.In order to facilitate use, And peripheral circuit is reduced, reduces cost, the utility model uses bus-powered mode, i.e., outside by the Vbus pin of USB interface USB device power supply is connect, specifically, Vbus voltage herein is operating voltage 5V.

Further, LED lamp D2 is additionally provided between the GL_N pin of chip U2 and the VCC pin of USB interface, herein LED Lamp D2 is used to indicate the communications status of USB interface, and specifically, LED light D2 can be based on referring to the default of GL_N pin Show, for example, chip U2 control GL_N pin intermittently drags down, such LED light when user equipment is just inserted into USB interface D2 enters flashing state, and when user equipment starts reading and writing data, chip U2 controls GL_N pin and keeps low level, at this time LED lamp D2 will be always on.It is to be appreciated that can be defined according to actual needs for the working condition of GL_N control LED light D2 The change of other modes is carried out, details are not described herein again.

It can be seen that the scheme of the utility model can indicate the working condition of USB by setting LED light D1 and LED light D2, When USB interface failure occurs in printer sharing, maintenance personnel can be allowed to know at the first time by indicator light, facilitated shared The maintenance of printer.

Specifically, the operating voltage of chip U1 and chip U2 are also 5V, that is, chip U1, chip U2 and USB interface all make With identical operating voltage, it is thus not necessarily to additional voltage conversion circuit, can effectively simplify the circuit structure of the utility model.

Specifically, chip U1 is STC12C5A60S2 chip；Chip U2 is PDIUSBD12 chip.Further, U1 and crystalline substance The Y1 that shakes is connected, and the oscillation frequency of Y1 is 11.0952MHz；U2 is connected with crystal oscillator Y2, and the oscillation frequency of Y2 is 6MHz.

It is to be appreciated that the USB interface of the utility model using human interface device (Human Interface Device, HID) agreement is to be able to use the included HID class driver of WINDOWS operating system using the advantage of HID protocol, from And save the driving exploitation for the USB interface of the utility model.It is apparent that USB can be enhanced by using HID protocol in the utility model Interface generality reduces the probability of happening of all kinds of driving problems.

It is to be appreciated that PDIUSB12 possesses the Serial Interface Engine PSIE function of PHILIPS Co.'s exploitation, the function is real Show whole USB protocol layers, participates in usb protocol by hardware realization without software completely.In this circuit base On, the USB connection procedure between the USB interface and user equipment of the utility model mainly includes mainly to control transmission mode progress Three phases, i.e. token cognitive phase, data transfer phase and protocol handshake stage.

Specifically, in token cognitive phase, user equipment is connect with USB interface, and USB device powers on, chip U1 and chip U2 is also at working condition, the pull-up resistor of 1.5K Ω is equipped on the data D- and data D+ pin of USB interface, according to upper The setting of D- and D+ level can carry out initialization definitions to access device when electric, be when for example, D+ being high level when setting powers on USB high-speed equipment has been accessed, has accessed USB non-high-speed equipment when D- is low level when powering on.By this stage, USB is connect Mouth can identify USB device type.

Further, in data transfer phase, chip U2 control D+ and D- is reset to low level state, and USB is arranged and sets The default address of standby and chip U2 transmission is respectively 0 and endpoint 0.It is that USB device distribution is logical that chip U1, which sends request to chip U2, Believe address.

Further, after mailing address is assigned, chip U1 obtains the descriptor letter of USB device by chip U2 Breath, specifically, descriptor information include the maximum packet length of endpoint 0, equipment support configuration and number, device type, port body Part information (port ID, PID) and USB supplier information (Vendor ID, VID) etc..

Further, after chip U1 confirms these information, chip U1 carries out automatic connection configuration to USB device.

Further, in the protocol handshake stage, printer sharing is completed connection configuration by chip U1, is sent to chip U2 Data command starts the data communication between user's USB device, realizes the connection communication function of USB.

It is apparent that the utility model can call USB to drive by using the hardware circuit scheme of HID interface protocol in system layer It is dynamic, thus simplify driver write and identification process, enhance the versatility and practicability of printer sharing USB interface.

Optionally, chip U1 can also be that other scm system chips, chip U2 can also be other meet demands USB control programming chip, details are not described herein again.

The utility model is not limited to above-mentioned specific embodiment, it should be understood that those skilled in the art are without wound The property made labour, which according to the present utility model can conceive, makes many modifications and variations.In short, all technologies in the art Personnel pass through logical analysis, reasoning, or a limited experiment according to the design of the utility model on the basis of existing technology to be obtained The technical solution arrived, all should be within the scope of protection determined by the claims.

Claims (7)

1. a kind of USB interface of printer sharing, which is characterized in that the circuit structure of USB interface includes: MCU chip U1 and USB Control chip U2；Wherein, the data/address bus of chip U2 is connected with the P0 of chip U1 mouth；The read-write strobe pin and chip of chip U2 Exterior read-write strobe pin P3.6 and the P3.7 correspondence of U1 is connected；In the outside of interrupt requests the pin INT_N and U1 of chip U2 Disconnected pin INT0 is connected；The chip selection signal pin of chip U2 is grounded, and address bit pin A0 is connected with the P3.5 of chip U1 control foot； The DMA response pin DMACK_N of chip U2 is also connected with interrupt requests pin INT_N, triggers for low level.

2. USB interface according to claim 1, which is characterized in that the circuit structure of the USB interface further includes that USB connects Mouthful, the USB interface has four operating voltage VCC, data D-, data D+ and ground connection pins, wherein the data D- sum number According to D+ for the data communication between the U2, LED light is additionally provided between the VCC pin and GND pin of the USB interface D1, the D1 are used to indicate the connection status of the USB interface.

3. USB interface according to claim 2, which is characterized in that the GL_N pin of the U2 and the USB interface LED light D2 is additionally provided between VCC pin, the D2 is used to indicate the communications status of the USB interface.

4. USB interface according to claim 1, which is characterized in that on the data D- and data D+ pin of the USB interface It is additionally provided with the pull-up resistor of 1.5K Ω.

5. USB interface according to claim 1, which is characterized in that the operating voltage of described U1, U2 and USB interface is 5V。

6. USB interface according to claim 1, which is characterized in that the U1 is connected with crystal oscillator Y1, the concussion frequency of the Y1 Rate is 11.0952MHz；The U2 is connected with crystal oscillator Y2, and the oscillation frequency of the Y2 is 6MHz.

7. any USB interface in -6 according to claim 1, which is characterized in that the U1 is STC12C5A60S2 chip, The U2 is PDIUSBD12 chip.