JP2001245017A - Usb simulation device and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To intentionally generate an error packet, an abnormal sequence in handshake or the like while maintaining handshake between a host and a device connected through a USB by a simulation program. SOLUTION: In this USB simulation device 1 in a performance form, a setting part 12a in a CPU 11 sets the address, transfer mode and band of a communicating device, a transaction managing part 12b manages test items (error packet, abnormal sequence, etc.), in each transaction, a received data deciding part 12c decides a response signal inputted from information informal decision, branches the subsequent processing in accordance with decision results and selects a test item to be conducted, data to be transmitted, etc., in the next transaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a USB (Universa)
The present invention relates to a USB simulation device for virtually performing and verifying a communication function of a personal computer or a peripheral device connected by a serial bus) and its operation.

[0002]

2. Description of the Related Art In recent years, keyboards, mice, speakers, modems, and the like that can be connected to a personal computer (host) by an interface conforming to the USB standard.
Many peripheral devices (devices) such as printers have been developed.

[0003] Communication between the host and the device by USB is controlled by USB protocol software of the host. That is, even when data is transmitted from the device side, the device transmits data to the host after the host gives the bus use right to the device.

[0004] More specifically, the host and each device have a USB-compliant controller. The USB controller on the host side issues a token packet to each device according to a program of USB protocol software. The token is a code used by the device to determine whether data is transmitted from the host to the device (OUT) or data is transmitted from the device to the host (IN). Perform the appropriate processing. The packet means a unit of information including information output by the host or the device, a code for identifying a data type, an address, and the like.

[0005] When communicating with a device, the host schedules communication with the device in units called transactions. For example, first, when the host transmits a token packet to the device and data exchange is completed, the data receiving side transmits a handshake packet to the transmitting side, and the communication unit called a transaction ends.

Note that data flowing on the USB is time-divided based on the concept of a frame, and an SOF (Start of Frame) packet is always added at the beginning of a frame. Following the SOF packet, the host transmits and receives each packet to and from the device in a previously scheduled order.

In the case of examining data flowing on such a USB bus by a test pattern or directly verifying a response from a device via the USB on the USB bus, a USB simulation model is generally used.

As shown in FIG. 8, a conventional dedicated simulator 20 for performing a USB simulation controls a memory 21 storing a pattern (USB simulation model) of transmission data to be output to a host or a device, and controls transmission timing of the transmission data. And a code conversion circuit 23 for modulating transmission data to USB serial data and demodulating received data.

That is, the dedicated simulator 20 converts the transmission pattern stored in the memory 21 into a code conversion circuit 23.
, A synchronization pattern is added, and output to a host or a device at the timing specified by the timing generator 22.

Further, as shown in FIG. 9, a USB simulation may be performed using a general-purpose USB controller LSI 31. 9, a USB simulation system 30 includes a USB controller LSI 31,
The control microcomputer 32 includes a control microcomputer 32 and USB driver software 33. The control microcomputer 32 controls the USB controller LSI 31 according to a test program stored in the USB driver software 33.

[0011]

However, in the conventional dedicated simulator 20 as shown in FIG. 8, when resynchronization timing is shifted or retransmission processing becomes necessary due to error data or the like, connection with a communication partner is required. Is cut off and normal simulation operation cannot be performed. In addition, when an error packet or an abnormal sequence is intentionally generated, the connection with the communication partner is disconnected each time, so that there is a problem that the working time becomes redundant.

On the other hand, in the USB simulation system 30 shown in FIG.
It is necessary to tune the contents of the SB driver software 33, which is troublesome. In the USB controller LSI 31, the control microcomputer 32 automatically processes data to be transmitted and received, and when an error occurs, requests a transmission retry signal to the data transmission side. Cannot occur.

As a technique of performing a simulation while maintaining a communication handshake, a method of executing a simulation program by performing software handling on a packet basis has been established as a conventional technique.
Since packet response during a transaction in USB is very fast, implementation with the same technology is difficult.

It is an object of the present invention to intentionally generate an abnormal sequence such as an error packet or a handshake while maintaining a handshake between a host and a device connected via a USB by a simulation program. .

[0015]

According to the first aspect of the present invention,
In a USB simulation device that virtually executes signal processing exchanged between a main device connected by USB and its peripheral device, a storage unit that stores a plurality of test items and simulation instructions, and the storage unit A transmission data management unit (for example, a transaction management unit 12b in the CPU 11 of FIG. 4) that manages data to be transmitted to one or more external devices connected by USB based on the stored contents; A setting unit (for example, a setting unit 12a in the CPU 11 in FIG. 4) for setting an address of the external device based on the stored contents and a timing for outputting data based on the contents stored in the storage unit are generated. Timing generation means (for example,
USB status monitoring unit 1 in USB controller 13 in FIG.
3c) and data transmission means (for example, in the USB controller 13 in FIG. 4) which outputs data instructed by the transmission data management means to the address set by the setting means at the timing generated by the timing generation means. A transmission control unit 13d), a receiving unit (for example, a status monitoring unit 13f in the USB controller 13 in FIG. 4) that receives a signal input from the external device via a USB, and a signal received by the receiving unit. A determination unit that determines the next data to be transmitted based on the signal and outputs the data to the transmission data management unit (for example, the CPU 11 in FIG.
, And functions as a virtual main device or a virtual peripheral device for an external device to be connected.

According to the first aspect of the present invention, in the USB simulation apparatus for virtually executing signal processing exchanged between a main device connected via USB and its peripheral devices, the storage means includes a plurality of test devices. Item and simulation instruction are stored, the transmission data management means manages data to be transmitted to one or more external devices connected by USB based on the contents stored in the storage means, and the setting means is Setting the address of the external device based on the content stored in the storage unit, the timing generation unit generates a timing to output data based on the content stored in the storage unit, and the data transmission unit ,
At the timing generated by the timing generating means, the data instructed by the transmission data managing means is output to the address set by the setting means, and the receiving means outputs a signal input from the external device via USB. And the determination unit determines the next data to be transmitted based on the signal received by the reception unit, and outputs the data to the transmission data management unit.

Therefore, the address of an external device to be connected can be changed according to the contents stored in the storage means, the timing of outputting data can be changed, or the data to be output next can be changed according to a signal input from the external device. Can be selected.

According to the second aspect of the present invention, the U
In the SB simulation apparatus, the transmission data management means manages data to be transmitted in transaction units.

Therefore, since information is managed in a unit, a process according to a signal input from an external device can be performed despite high-speed communication performed in the USB bus.

The invention according to claim 3 is the same as the invention according to claim 2,
The SB simulation apparatus is characterized in that the transmission data management means intentionally generates error data or an abnormal sequence.

Therefore, the response of the external device to the error data or the abnormal sequence can be inspected.

According to a fourth aspect of the present invention, the U
In the SB simulation apparatus, the determining unit determines the next data to be transmitted based on the handshake signal input from the external device received by the receiving unit, and connects the communication until all test items for the external device are completed. Is not cut.

Therefore, even if error data or an abnormal sequence occurs, the connection with the external device is not cut off and the USB
Operations such as logic verification in simulation and signal search in the bus can be efficiently executed.

According to a fifth aspect of the present invention, the U
In the SB simulation apparatus, the setting unit includes:
It is characterized in that an address of an external device for transmitting data is set, and a transfer characteristic of data to be transmitted is set to an arbitrary mode.

Therefore, the transmission according to the transfer mode can be performed with the address set to the connected external device, and the abnormal response of the external device can be inspected by transmitting the packet in an abnormal sequence in the mode.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a USB simulation device according to an embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a block diagram showing a USB connection configuration in which a host 2 and a plurality of peripheral devices (hereinafter, device 3) are connected to a USB simulation device 1. FIG.
, The USB simulation device 1 is connected to the USB controllers 2b and 3b of each device.

In the present embodiment, the USB simulation device 1 communicates with the device 3 as a virtual host (see FIG. 2) or communicates with the host 2 as a virtual device (see FIG. 3).

FIG. 4 is a block diagram showing the internal configuration of the USB simulation device 1 according to the present embodiment. In FIG. 4, the USB simulation device 1
It comprises a storage medium 10, a CPU 11, and a USB controller 13.

The storage medium 10 is configured to be readable by the CPU 10 such as a magnetic or optical storage medium or a semiconductor memory. The storage medium 10 may be a medium that is removable from the USB simulation device 1 or a fixed medium such as a hard disk. Including. The storage medium 10 stores a control program for controlling the USB controller 13, a USB simulation program, and the like.

The CPU 11 controls the USB controller 13 according to a program stored in the storage medium 10. The CPU 11 executes the USB simulation program stored in the storage medium 10 by the setting unit 12a, the transaction management unit 12b, and the received data determination unit 13c.

The setting unit 12a defines a transfer mode, a band, and an address setting of a device to be simulated, and outputs an instruction signal to the address management unit 13a and the band management unit 13b in the USB controller 13.

In the USB, communication is performed by controlling the bus occupation band for one communication pipe. For example, interrupt transfers for interrupting and processing signals input from devices such as keyboards and mice in communications with other devices, bulk transfers for transferring large amounts of data, and interruptions in audio and video are troublesome. There are transfer modes such as isochronous transfer for transferring data and control transfer for the host to acquire device configuration information.

That is, the setting unit 12a determines which device communicates with which transfer mode. Also, an instruction signal for shifting the output timing of the SOF packet added to the beginning of the frame or generating an abnormal sequence is sent to the address management unit 13a in the USB controller 13,
Output to the band management unit 13b.

The transaction management unit 12b reads out the contents of the data to be transmitted from the storage medium 10 and expands it in the transmission buffer 13e, and a transmission control signal for controlling the generation of an error packet and the generation of an abnormal sequence of a handshake response. Is generated, and the USB controller 13 is generated.
To the transmission control unit 13d.

A transaction is a unit of schedule that is set in advance by the host to establish communication with the device, and is, for example, a combination of transfer data that starts with an action of starting communication from the host to the device and ends with a handshake. . That is, the transaction management unit 12b, based on the determination result by the reception data determination unit 12c and the program stored in the storage medium 10,
Determine each packet in the transaction, such as token packets, data packets, handshake packets, etc., and make a combination of them.

The reception data determination unit 12c determines whether the response of the communication partner is normal or abnormal based on the data input from the status monitoring unit 13f in the USB controller 13, branches the processing, and executes the next transaction. The data to be output is determined, and the processing result is output to the transaction management unit 12b.

For example, the reception data judgment unit 12c judges the response of the output error packet or abnormal sequence based on the handshake packet input from the communication partner, and determines the output data for not continuing the handshake. Is determined by a conditional branch.

When performing control transfer between the host and the device, the host outputs a descriptor transfer request (setup packet) to the device in order to know the state of the device. What is a descriptor?
This code indicates the connection status and processing status of the device. Therefore, when the USB simulation device 1 is a virtual host and performs control transfer with a device,
The reception data determination unit 12c performs a process according to the descriptor input from the device.

The USB controller 13 includes an address management unit 13a, a band management unit 13b, a USB status monitoring unit 13
c, a transmission control unit 13d, a transmission buffer 13e, a status monitoring unit 13f, and a control data capture 13g, and operate in accordance with an instruction input from the CPU 11.

The address management unit 13a manages device addresses according to instructions input from the setting unit 12a in the CPU 11, and outputs the device addresses to the USB status monitoring unit 13c. In other words, when the USB simulation device 1 is a virtual host, it manages the addresses of one or more connected devices, and
Is a virtual device, manages the address given by the host.

The band management unit 13b controls a transmission mode and a transmission timing of a signal to be output in accordance with an instruction input from the setting unit 12a in the CPU 11.

The USB status monitoring unit 13c monitors the USB bus status based on the data input from the address management unit 13a, the bandwidth management unit 13b, and the received data determination unit 13f, and determines the transmittable timing, mode, and address. And the like to the transmission control unit 13d.

The transmission control unit 13d generates each packet in accordance with an instruction input from the transaction management unit 12b in the CPU 11, and outputs the packet to the USB bus according to the timing and transfer mode input from the USB controller 13. When outputting data, the data in the transmission buffer 13e expanded according to the transmission command input from the transaction management unit 12b is output as a data packet.

The status monitor 13f decodes a handshake packet or data packet (descriptor or the like) input from a connection partner via the USB bus,
Output to the CPU 11 and the USB status monitoring unit 13c.

The control data capture 13
g stores the decryption result of the status monitoring unit 13f, and the stored decryption result is read from the status monitoring unit 13f in response to an instruction signal input from the CPU 11, and output to the received data determination unit 12c. By storing the status of the communication partner in the control data capture 13g in this way, a program that accurately reflects the setup information in the control transfer is executed.

Next, the operation of the embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a protocol flow illustrating an OUT transaction when the USB simulation device 1 is a virtual host and data is transferred to the device 3 (see FIG. 2).

In FIG. 5, the CPU 11 of the USB simulation apparatus 1 (virtual host) sets the transfer mode, the band, the address of the device 3 to communicate with, etc. (step S1), and sets the address management unit 1 of the USB controller 13
3a and output to the band management unit 13b.

Then, the CPU 11 controls the transmission control unit 13d
To output a token packet generation instruction. After generating the token packet according to the instruction of the CPU 11, the transmission control unit 13d outputs the token packet to the specified transfer mode, band, and address (device 3) according to the timing input from the USB status monitoring unit 13c (step). S2).

When step S2 ends, the CPU 11
Transmits the data output by the virtual host 1 in the transaction to the transmission buffer 1 in the USB controller 13.
3d (step S3), and outputs a data packet generation instruction to the transmission control unit 13d. Transmission control unit 13
d is the transmission buffer 13e according to the instruction of the CPU 11.
When the data to be transmitted is read from the inside, a data packet is generated, and the data packet is output to the device 3 according to the timing input from the USB status monitoring unit 13c (step S4).

On the other hand, when a data packet is input from the virtual host 1, the device 3 determines whether or not the data has been normally received, generates a handshake packet, and outputs the handshake packet to the virtual host 1. (Step S5).

The CPU 11 grasps the communication state of the device 3 from the handshake packet input from the device 3 (step S6), selects a token or data to be output in the next transaction, and combines each packet in the transaction. To determine.

As described above, the OU when the USB simulation apparatus 1 outputs data to the device 3 by the virtual host
The flow of the T transaction has been described. Conversely, when the device 3 transmits data to the virtual host 1, when the virtual host 1 outputs a token packet to the device 3, the device 3 outputs a data packet to the virtual host 1. Then, the CPU 11 in the virtual host 1 selects a handshake to be output according to the received data packet, and outputs the handshake packet to the device 3 when the handshake packet is generated.

The selection of the handshake may be based on a control protocol according to the USB standard, or may be intentionally selected by a determination command stored in the storage medium 10 in advance. Further, an error can be generated by shifting the timing of outputting the handshake packet.

Next, when the USB simulation apparatus 1 is a virtual device and outputs data to the host 2 (FIG. 3)
6) will be described based on the protocol flow shown in FIG.

In FIG. 6, when the host 2 generates a token packet and outputs it to the virtual device 1 (step S10), the CPU 11 of the virtual device 1 transfers the data to be transferred to the transfer buffer 13e in the USB controller 13.
(Step S11), and outputs a data packet generation instruction to the transmission control unit 13d.

The transmission control unit 13d generates a data packet and outputs the data packet to the host 2 according to the timing input from the USB status monitoring unit 13c (step S12).

The host 2 sends data from the virtual device 1
When a packet is input, a handshake packet is generated and output to the virtual device 1 (step S13).

The CPU 11 grasps the communication state of the host 2 from the handshake packet input from the host 2 (step S14), and determines data to be output from the virtual device 1 in the next transaction.

The IN transaction in the case where the virtual device 1 transfers data to the host 2 has been described. Conversely, in the case of an OUT transaction in which the host 2 transfers data to the virtual device 1, the CPU 11
Generates a handshake packet based on the received token packet and data packet, and
Output to

Subsequently, when the USB simulation apparatus 1 is a virtual host and executes communication by control transfer with the device 3 (see FIG. 2), the device 3 outputs a descriptor in response to a request from the virtual host 1. The IN transaction at this time will be described using the protocol flow shown in FIG.

In FIG. 7, the CPU 11 of the virtual host 1
Sets the transfer mode, the band, the address of the device 3 to communicate with, and the like (step S20), and sends the instruction signal to the address management unit 13a and the band management unit 1 of the USB controller 13.
3b.

Further, the CPU 11 outputs a token packet generation instruction to the transmission control unit 13d. Transmission control unit 1
When generating the token packet according to the instruction of the CPU 11, the 3d outputs the token packet to the specified transfer mode, band, and address (the device) according to the timing input from the USB status monitoring unit 13c (step S21).

On the other hand, when the token packet is input from the virtual host 1, the device 3 generates a data packet (descriptor) and outputs it to the virtual host 1 (step S22).

The CPU 11 grasps the state of the device 3 from the descriptor input from the device 3 (step S23), selects a token or data to be output in the next transaction, and determines a combination of each packet in the transaction.

Next, the CPU 11 transmits the received data
A handshake packet for the packet is generated and output to the device 3 (Step S24).

The IN transaction in which the device 3 outputs a descriptor to the virtual host 1 has been described above. Conversely, in the embodiment shown in FIG. 3, the present invention is applied to an OUT transaction in which the virtual device 1 outputs a descriptor to the host 2. May be applied. That is, the contents of the descriptor output by the virtual device 1 are changed in accordance with the status setting command stored in the storage medium 10 in advance.

As described above, the USB simulation apparatus 1 according to the embodiment of the present invention sets the address, transfer mode, and band of the device to be communicated by the setting unit 12a in the CPU 11, and sets the transaction management unit 12b.
To set test items (error packets, abnormal sequences, etc.) for each transaction,
In 2c, a response signal input from the communication offer is determined, and the subsequent processing is branched according to the determination result, and a test item to be executed in the next transaction, data to be transmitted, and the like are selected.

Therefore, the USB simulation device 1
Can change the content of the next transaction in accordance with the response signal input from the communication partner, so that the handshake with the communication partner can be maintained. Further, the transfer mode of the signal output by the USB simulation device 1 can be changed at any time by the setting unit 12a in the CPU 11, so that an abnormal signal can be transmitted in real time and the response can be checked.

Further, since the processing unit of the simulation executed by the CPU 11 is not a packet but a transaction, it is possible to cope with high-speed USB communication.

It should be noted that the present invention is not limited to the contents described in the above embodiment, but can be appropriately changed without departing from the spirit of the present invention. For example, the present invention may be modified so that the present invention can be executed using the CPU 2a and the USB controller 2b of the host 2. Also, FIG.
FIG. 7 shows the protocol flows in the embodiment of the present invention, but these flows are appropriately changed according to the test items and the response signals of the communicating devices.

[0071]

According to the USB simulation apparatus of the first aspect and the storage medium of the sixth aspect, the timing of changing the address of an external device to be connected or outputting data in accordance with the content stored in the storage means. Or change
Data to be output next can be selected according to a signal input from an external device.

According to the second aspect of the present invention, since the transmission data management means manages the data in transaction units, even if the communication exchanged in the USB bus is at a high speed, the data is input from an external device. Processing according to the signal can be performed.

According to the USB simulation device of the third aspect, since the transmission data management means generates error data and an abnormal sequence, it is possible to inspect the response signal of the external device in these unusual situations.

According to the USB simulation device of the fourth aspect, since the determination means selects the next data to be transmitted in accordance with the handshake signal input from the external device, error data or an abnormal sequence is generated. The connection with the external device can be maintained later.

According to the USB simulation device of the fifth aspect, since the setting means can change the transfer characteristics of the data to be transmitted, it can transmit the data in a mode different from the transfer mode of the connected external device. Therefore, the response of the external device to the abnormal signal can be inspected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a connection mode of a USB simulation device 1.

FIG. 2 is a block diagram showing a connection between the USB simulation apparatus 1 and a device 3.

FIG. 3 is a block diagram showing a connection between the USB simulation device 1 and a host 2.

FIG. 4 is a block diagram showing an internal configuration of the USB simulation device 1.

FIG. 5 is a protocol flow of an OUT transaction.

FIG. 6 is a protocol flow of an IN transaction.

FIG. 7 is a protocol flow when a descriptor is transmitted and received.

FIG. 8 is a block diagram showing a configuration of a conventional dedicated simulator 20.

FIG. 9 is a block diagram showing a conventional USB simulation system 30.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 USB simulation apparatus 10 Storage medium 11 CPU 12a Setting part 12b Transaction management part 12c Received data judgment part 13 USB controller 13a Address management part 13b Bandwidth management part 13c USB state monitoring part 13d Transmission control part 13e Transmission buffer 13f Status monitoring part 13g Control Data capture 2 Host 2a CPU 2b USB controller 3 Device 3a USB device 3b USB controller 4 USB (bus)

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Claims (6)

[Claims] 1. A USB for virtually executing signal processing exchanged between a main device and its peripheral devices connected by USB.
In the simulation device, a storage unit that stores a plurality of test items and a command on a simulation, and manages data to be transmitted to one or more external devices connected by USB based on the content stored in the storage unit. Transmission data management means, setting means for setting the address of the external device based on the contents stored in the storage means, and timing generation for generating a timing for outputting data based on the contents stored in the storage means Means, at a timing generated by the timing generating means, data transmitting means for outputting data instructed by the transmission data managing means to an address set by the setting means, and input from the external device via USB Receiving means for receiving a signal to be received, and a signal received by the receiving means. And a determination unit for determining data to be transmitted next based on the transmission data management unit, and functioning as a virtual main device or a virtual peripheral device for an external device to be connected. USB simulation device. 2. The USB simulation apparatus according to claim 1, wherein said transmission data management means manages data to be transmitted in transaction units. 3. The USB simulation apparatus according to claim 2, wherein said transmission data management means intentionally generates error data or an abnormal sequence. 4. The determination means determines next data to be transmitted based on a handshake signal input from the external device received by the reception means, and all test items for the external device are completed. 4. The USB simulation apparatus according to claim 3, wherein the communication connection is not disconnected until the connection. 5. The USB simulation apparatus according to claim 1, wherein said setting means sets an address of an external device to which data is transmitted, and sets a transfer characteristic of data to be transmitted to an arbitrary mode. 6. A virtual main device or a virtual peripheral device for a connected external device by virtually executing signal processing exchanged between a main device connected via USB and its peripheral device. A storage medium storing a computer-executable program for performing, based on a plurality of test items and simulation instructions, data to be transmitted to one or more external devices connected via USB. A program code for managing, a program code for setting an address of the external device based on a plurality of test items and a simulation instruction, and outputting data based on a plurality of test items and a simulation instruction. A program code for generating timing, and managing the set address at the timing. A program code for outputting data to be transmitted from the external device via a USB, and a program for determining next data to be transmitted based on the received signal. A storage medium for storing a program including a code.