JP2008064695A - Testing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To support detection of abnormality of a testing device or processing and removal of fault dealing. <P>SOLUTION: The testing device for testing a device to be tested connects an interface part and each of testing units in the form of a link, and includes a link network propagating a command to one direction. The interface part has: a first interface 200 connected to a control device; a second interface 210 connected to the link network; a time-out processing part 220 for performing time-out of the command from the control device in response to performing the time-out on the link network by the command output to the link network; an abnormality detection part 250 for detecting abnormality of the link network; and an abnormality processing part 240 for completing without outputting the command received from the control device to the link network after detecting abnormality of the link network. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a test apparatus for testing a device under test. In particular, the present invention relates to a test apparatus including a plurality of test units.

  Recent test equipment has multiple test units such as a pattern generator that generates test patterns and a timing generator that generates timing signals, enabling efficient testing of high-performance devices under test It is said. A test apparatus having a plurality of test units has a control apparatus for controlling the test units. The control device operates according to a preset program, and transmits a command, data, and the like for controlling the test unit to each test unit.

JP 2003-57305 A JP 2003-108516 A

  If a failure occurs in the command transmission path or the test unit, the response of the command to the test unit from the control device may not be detected. In such a case, the control device waits for the command to time out and performs the next process such as a retransmission process. However, when a plurality of test units and the control device are connected via a ring network, once a failure occurs, communication with other test units cannot be normally performed thereafter. For this reason, when the control device transmits a command many times, timeouts occur continuously, hindering other processing by the control device. As a result, for example, there is a possibility that the discovery of the failure and the processing for the failure will be delayed.

  Accordingly, an object of the present invention is to provide a test apparatus that can solve the above-described problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous specific examples of the present invention.

  According to one aspect of the present invention, there is provided a test apparatus for testing a device under test, a plurality of test units for testing the device under test, and a plurality of tests by transmitting a command to each of the plurality of test units. A control device that controls the operation of each unit, an interface unit that is connected between the control device and the plurality of test units, and an interface unit and each of the plurality of test units that are connected in a ring shape to ring a command A ring network that propagates in one direction, and the interface unit includes a first interface connected to the control device, a second interface connected to the ring network, and a command output to the ring network on the ring network. In response to a timeout, type a command from the control unit. A timeout processing unit to be out, an abnormality detection unit to detect an abnormality of the ring network, and an abnormality processing unit to complete a command received from the control device after the abnormality of the ring network is detected without being output to the ring network; A test apparatus is provided.

In addition, the abnormality detection unit detects an abnormality of the signal that is output to the ring network via the second interface and should return to the second interface via each test unit on the ring network. An abnormality of the ring network may be detected.
The anomaly detection unit detects an anomaly in the ring network in response to the clock signal indicating the command acquisition timing output to the ring network via the second interface not being input to the second interface. May be.

In addition, the abnormality detection unit determines whether the command output to the ring network via the second interface does not return to the second interface via each test unit on the ring network. Anomalies may be detected.
The second interface generates a dummy command at a predetermined time interval and outputs the dummy command to the ring network. The anomaly detector detects that the dummy command passes through each test unit on the ring network. An abnormality of the ring network may be detected in response to failure to return to the normal state.

Each of the plurality of test units outputs an acknowledge signal to the ring network in response to receiving a command destined for the test unit, and the ring network propagates the acknowledge signal in the opposite direction to the command. The second interface selects one test unit from a plurality of test units in order and sequentially transmits dummy commands destined for the test unit. Abnormality that detects that there is a problem in command transmission to the one test unit in response to not receiving an acknowledge signal indicating that the dummy command has been accepted from one test unit when an abnormality is detected You may further provide a location detection part.
The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

  FIG. 1 shows a functional configuration of the test apparatus 10. The test apparatus 10 includes a control unit 20, a timing generator 30, a pattern generator 40, a power supply unit 50, a test head 60, and a ring network 70, and determines whether the device under test 100 is good or bad. Objective. Each of the timing generator 30, the pattern generator 40, the power supply unit 50, and the test head 60 is a test unit for testing the device under test 100, and tests the device under test 100 in cooperation with each other. For example, the timing generator 30 generates a predetermined clock signal and supplies it to the pattern generator 40. The pattern generator 40 outputs a test pattern to be supplied to the device under test 100 to the test head 60 in accordance with a given clock signal. Further, the pattern generator 40 outputs an expected value pattern to the test head 60. The test head 60 supplies the received test pattern to the device under test 100. In addition, the test head 60 determines the pass / fail of the device under test 100 by acquiring the test pattern output from the device under test 100 and comparing it with the expected value pattern. The power supply unit 50 supplies power to these test units.

  The control unit 20 transmits a command to each of the plurality of test units in accordance with a control program 80 input in advance, and controls the operation of each of the plurality of test units. For example, the control unit 20 may perform a predetermined initial setting for the test unit before the start of the test, or may set a predetermined parameter for a register in the test unit. Specifically, the control unit 20 includes a control device 22 and an interface unit 24. The control device 22 transmits commands to the timing generator 30, the pattern generator 40, the power supply unit 50, and the test head 60 via the interface unit 24. The interface unit 24 is connected between the control device 22 and the plurality of test units. Specifically, the interface unit 24 is connected to the control device 22 by a general-purpose bus such as a PCI bus. The interface unit 24 is connected to the timing generator 30, the pattern generator 40, the power supply unit 50, and the test head 60 through a ring network 70 that is a dedicated signal transmission path. The ring network 70 connects the interface unit 24 and each of the plurality of test units in a ring shape, and propagates commands in one direction of the ring.

  FIG. 2 shows a functional configuration of the interface unit 24. The interface unit 24 includes a first interface 200, a second interface 210, a timeout processing unit 220, an abnormality detection unit 230, an abnormality processing unit 240, an abnormal part detection unit 250, and a selection unit 260. The first interface 200 is connected to the control device 22, and includes a first reception circuit 202 that receives a signal such as a command from the control device 22, and a first transmission circuit 204 that transmits a signal such as a command to the control device 22. Have. The second interface 210 is connected to the ring network 70. Then, the second interface 210 obtains a command to be output on the ring network 70 from the first receiving circuit 202 and temporarily stores it, and takes out the command from the buffer 212 and places it on the ring network 70. A second transmitting circuit 214 for transmitting and a second receiving circuit 216 for receiving a command from the ring network 70 are included. A first processing example in which a command is transmitted to each test unit by the first interface 200 and the second interface 210 will be described below.

  FIG. 3 is a time chart showing the operation of the test apparatus 10 in the first processing example. The control device 22 issues a write command (Write TG, DATA1) to the timing generator 30 (S300). This command is received by the first interface 200, temporarily stored in the buffer 212, and output on the ring network 70 by the second interface 210. This command returns to the second interface 210 via the pattern generator 40, the timing generator 30, the power supply unit 50, and the test head 60 in order. When receiving the command, the timing generator 30 performs a writing process according to the content (S310). Then, the timing generator 30 propagates an acknowledge signal to the effect that the writing process is completed on the ring network 70 in the direction opposite to the command and inputs the acknowledge signal to the second interface 210.

  Independently of these processes, the control device 22 issues a write command (Write DPU, DATA2) to the power supply unit 50 (S320). This command is received by the first interface 200 and stored in the buffer 212. When the second interface 210 receives the acknowledge signal from the timing generator 30, the second interface 210 retrieves the next command from the buffer 212 (S330). Then, the second interface 210 outputs the extracted command on the ring network 70. This command returns to the second interface 210 via the pattern generator 40, the timing generator 30, the power supply unit 50, and the test head 60 in order. When receiving the command, the power supply unit 50 performs a writing process according to the content (S350). Then, the power supply unit 50 propagates an acknowledge signal to the effect that the writing process is completed on the ring network 70 in the direction opposite to the command and inputs the acknowledge signal to the second interface 210.

  Independently of these processes, the control device 22 issues a read command (Read PG) to the pattern generator 40 (S340). This command is received by the first interface 200 and stored in the buffer 212. When receiving the acknowledge signal from the power supply unit 50, the second interface 210 takes out the next command from the buffer 212 (S360). Then, the second interface 210 outputs the extracted command on the ring network 70. This command returns to the second interface 210 via the pattern generator 40, the timing generator 30, the power supply unit 50, and the test head 60 in order. When receiving this command, the pattern generator 40 performs a reading process according to the content (S370). Then, the pattern generator 40 propagates the read data in the same direction as the command on the ring network 70 and inputs it to the second interface 210. This data is returned to the control device 22 via the first interface 200. Upon receiving the data reply, the control device 22 performs the following process (S380).

  Returning to FIG. The timeout processing unit 220 times out a command from the control device 22 in response to a command output to the ring network 70 being timed out on the ring network 70. Information indicating that a timeout has occurred may be notified to the control device 22 via the selection unit 260 and the first interface 200, or may be output to the abnormality detection unit 230 and the abnormality point detection unit 250. An example of a process in which a timeout occurs is shown in FIG.

  FIG. 4 is a time chart showing the operation of the test apparatus 10 in the second processing example. The control device 22 issues a write command (Write TG, DATA1) to the timing generator 30 (S400). This command is received by the first interface 200, temporarily stored in the buffer 212, and output on the ring network 70 by the second interface 210. This command should be sent back to the second interface 210 via the pattern generator 40, the timing generator 30, the power supply unit 50 and the test head 60 in order, but the network between the timing generator 30 and the power supply unit 50. Is not properly replied because is disconnected. However, since the timing generator 30 as the destination is connected to the near side from the cut point, this command can be received. Therefore, the timing generator 30 performs a writing process according to this command (S410). Then, the timing generator 30 propagates an acknowledge signal to the effect that the writing process is completed on the ring network 70 in the direction opposite to the command and inputs the acknowledge signal to the second interface 210.

  Independent of these processes, the control device 22 issues a write command (Write DPU, DATA2) to the power supply unit 50 (S420), and issues a read command (Read PG) to the pattern generator 40 (S440). . These commands are received by the first interface 200 and stored in the buffer 212. When receiving the acknowledge signal from the timing generator 30, the second interface 210 takes out the next command from the buffer 212 (S430). Then, the second interface 210 outputs the extracted command on the ring network 70. This command should be sent back to the second interface 210 via the pattern generator 40, the timing generator 30, the power supply unit 50 and the test head 60 in order, but the network between the timing generator 30 and the power supply unit 50. Is not properly replied because is disconnected. For this reason, this command does not reach the destination power supply unit 50 normally. Therefore, no acknowledge signal is returned.

  The timeout processing unit 220 determines that the command output to the ring network 70 has timed out on the ring network 70 when a predetermined period has elapsed since the command was output (S450). Then, the second interface 210 takes out the next command from the buffer 212 (S460). This command should be sent back to the second interface 210 via the pattern generator 40, the timing generator 30, the power supply unit 50 and the test head 60 in order, but the network between the timing generator 30 and the power supply unit 50. Is not properly replied because is disconnected. However, since the destination pattern generator 40 is connected to the front side of the cut portion, this command can be received. Therefore, the pattern generator 40 performs a reading process according to the command (S470). The read data should be propagated in the same direction as the command on the ring network 70 and input to the second interface 210, but does not reach the second interface 210 due to disconnection.

In this case, the timeout processing unit 220 determines that the command output to the ring network 70 has timed out on the ring network 70. In response to determining that the time-out has occurred, the time-out processing unit 220 notifies the control device 22 of the time-out so as to time out the command from the control device 22 (S480). In response to this, the control device 22 performs the following process (S490).
As described above, since the process shown in FIG. 4 is determined based on whether or not the disconnection of the ring network 70 has timed out, the determination takes a long time. Therefore, the start of the next process in the control device 22 is delayed, and it may be difficult to find and eliminate the failure.

Returning to FIG. The abnormality detection unit 230 detects an abnormality in the ring network 70. The abnormality processing unit 240 completes the command received from the control device 22 after the above detection of the ring network 70 is detected without outputting it to the ring network 70. An example of this processing is shown in FIG.
FIG. 5 is a time chart showing the operation of the test apparatus 10 in the third processing example. The abnormality detection unit 230 detects an abnormality of a signal that is output to the ring network 70 via the second interface 210 and should return to the second interface 210 via each test unit on the ring network 70. Accordingly, an abnormality of the ring network 70 is detected (S500). The signal to be returned here is, for example, a clock signal indicating the acquisition timing of the command output to the ring network 70 via the second interface 210, and specifically, the timing signal itself (TCLK signal) or For example, a TSTART signal indicating the start of timing signal output. Alternatively, the signal to be returned may be a signal indicating a command output to the ring network 70 via the second interface 210, or generated at a time interval specified in advance by the second interface 210. The dummy command may be output to the ring network 70.

  When the abnormality of the ring network 70 is detected, the abnormality detection unit 230 notifies the abnormality processing unit 240 accordingly. Furthermore, it is desirable that the abnormality detection unit 230 prohibits subsequent writing to the buffer 212 in order to maintain the state of the buffer 212 when the abnormality is detected. Thereby, since the state at the time of abnormality detection can be maintained, the operation | work which investigates the cause of a failure after completion | finish of operation | movement of the test apparatus 10 can be supported.

  Independently of this process, the control device 22 issues a write command (Write TG, DATA1) to the timing generator 30 (S510). This command is received by the first interface 200 and is temporarily stored in the buffer 212 if it is normal. However, since the abnormality detection unit 230 has received notification that an abnormality has been detected, the command received by the first interface 200 is completed without being output to the ring network 70, and notification that it has been completed. Is transmitted to the control device 22 via the first interface 200 (S520).

  Further, the control device 22 issues a write command (Write DPU, DATA2) to the power supply unit 50 (S530). This command is received by the first interface 200 and is stored in the buffer 212 if it is normal. However, since the abnormality detection unit 230 has received notification that an abnormality has been detected, the command received by the first interface 200 is completed without being output to the ring network 70, and notification that it has been completed. Is transmitted to the control device 22 via the first interface 200 (S540).

  Further, the control device 22 issues a read command (Read PG) to the pattern generator 40 (S550). This command is received by the first interface 200 and is stored in the buffer 212 if it is normal. However, since the abnormality detection unit 230 has received notification that an abnormality has been detected, the command received by the first interface 200 is completed without being output to the ring network 70, and notification that it has been completed. Is transmitted to the control device 22 via the first interface 200 (S560).

  In response to this, the control device 22 performs the following process (S570). As described above, according to the processing described with reference to FIG. 5, the command received after the abnormality is once detected is immediately terminated without waiting for the time-out process. It is possible to immediately shift to the next processing. As a result, it is possible to promptly detect abnormality and respond to it.

  Returning to FIG. When the abnormality detection unit 230 detects that the transmitted clock signal is returned from the ring network 70 to the second interface 210, the abnormality detection unit 230 determines that the abnormality has been removed, and the abnormality processing unit 240 detects the abnormality. It may be instructed to cancel the process. Upon receiving this instruction, the abnormality processing unit 240 stores a command that the first interface 200 subsequently receives from the control device 22 in the buffer 212 and causes the second interface 210 to transmit the command to the ring network 70. Moreover, when the abnormality detection unit 230 detects an abnormality in the ring network 70, the abnormal part detection unit 250 may further detect which command unit has a problem in command transmission. Details of this processing will be described with reference to FIG.

  FIG. 6 is a time chart showing the operation of the test apparatus 10 in the fourth processing example. When an abnormality is detected in the ring network 70, the second interface 210 sequentially selects one test unit from among the plurality of test units and transmits a dummy command whose destination is the selected test unit. That is, first, the second interface 210 selects the pattern generator 40 and transmits a dummy command to the pattern generator 40 (S600). The transmitted dummy command should be returned to the second interface 210 via the pattern generator 40, the timing generator 30, the power supply unit 50, and the test head 60 in order. Since the ring network 70 between the units 50 is disconnected, the reply is not made normally. However, since the destination pattern generator 40 is connected to the front side of the cut portion, the dummy command can be received. Therefore, the pattern generator 40 generates an acknowledge signal according to this dummy command, propagates it in the opposite direction to the dummy command on the ring network 70, and inputs it to the second interface 210 (S605). The reception of the acknowledge signal is notified to the abnormal point detection unit 250.

  Next, the second interface 210 selects the timing generator 30 and transmits a dummy command to the timing generator 30 (S610). The transmitted dummy command should be returned to the second interface 210 via the timing generator 30, the timing generator 30, the power supply unit 50, and the test head 60 in order. Since the ring network 70 between the units 50 is disconnected, the reply is not made normally. However, since the timing generator 30 as the destination is connected to the near side from the cut point, the dummy command can be received. Therefore, the timing generator 30 generates an acknowledge signal according to the dummy command, propagates it in the opposite direction to the dummy command on the ring network 70, and inputs it to the second interface 210 (S615). The reception of the acknowledge signal is notified to the abnormal point detection unit 250.

  Next, the second interface 210 selects the power supply unit 50 and transmits a dummy command to the power supply unit 50 (S620). The transmitted dummy command should be returned to the second interface 210 via the timing generator 30, the timing generator 30, the power supply unit 50, and the test head 60 in order. Since the ring network 70 between the units 50 is disconnected, the reply is not made normally. Furthermore, since the power supply unit 50 as the destination is connected to the back side from the disconnection point, this dummy command cannot be received. Therefore, no acknowledge signal is returned from the power supply unit 50.

  Next, the second interface 210 selects the test head 60 and transmits a dummy command to the test head 60 (S630). The transmitted dummy command should be returned to the second interface 210 via the timing generator 30, the timing generator 30, the power supply unit 50, and the test head 60 in order. Since the ring network 70 between the units 50 is disconnected, the reply is not made normally. Further, since the test head 60 as the destination is connected to the back side from the cut portion, this dummy command cannot be received. Therefore, no acknowledge signal is returned from the power supply unit 50.

  The abnormal part detection unit 250 detects which test unit has a problem in command transmission based on the notification that the acknowledgment signal has been returned (S640). For example, in the example of FIG. 6, the abnormal part detection unit 250 determines that there is a problem in command transmission to the power supply unit 50 and the test head 60 because only command transmission to the pattern generator 40 and the timing generator 30 succeeds. Furthermore, it may be determined that a failure is suspected in the ring network 70 between the timing generator 30 and the power supply unit 50 based on the information on the connection arrangement of the test units on the ring network 70 given in advance.

  As described above, according to the test apparatus 10 shown in the present embodiment, when a communication failure occurs in the ring network 70, the subsequent command is automatically failed and the next process by the control apparatus 22 is started quickly. Can do. Since this function is realized not by the control program 80 in the control device 22 but by the interface unit 24 that connects the control device 22 and the ring network 70, it is necessary to modify the conventional control program 80 that operates in the control device 22. The existing assets can be used effectively. Further, when an abnormality is detected, a command buffered at the time of abnormality can be maintained, and a portion suspected of being an abnormality occurrence can be automatically detected, and subsequent failure handling can be made efficient.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

FIG. 1 shows a functional configuration of the test apparatus 10. FIG. 2 shows a functional configuration of the interface unit 24. FIG. 3 is a time chart showing the operation of the test apparatus 10 in the first processing example. FIG. 4 is a time chart showing the operation of the test apparatus 10 in the second processing example. FIG. 5 is a time chart showing the operation of the test apparatus 10 in the third processing example. FIG. 6 is a time chart showing the operation of the test apparatus 10 in the fourth processing example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Test apparatus 20 Control unit 22 Control apparatus 24 Interface part 30 Timing generator 40 Pattern generator 50 Power supply unit 60 Test head 70 Ring network 80 Control program 100 Device under test 200 1st interface 202 1st receiving circuit 204 1st transmitting circuit 210 Second interface 212 Buffer 214 Second transmission circuit 216 Second reception circuit 220 Timeout processing unit 230 Abnormality detection unit 240 Abnormality processing unit 250 Abnormal point detection unit 260 Selection unit

Claims (6)

A test apparatus for testing a device under test,
A plurality of test units for testing the device under test;
A control device that transmits a command to each of the plurality of test units to control the operation of each of the plurality of test units;
An interface unit connected between the control device and the plurality of test units;
A ring network that connects the interface unit and each of the plurality of test units in a ring shape and propagates the command in one direction of the ring, and
The interface unit is
A first interface connected to the control device;
A second interface connected to the ring network;
A time-out processing unit that times out the command from the control device in response to a time-out on the ring network of the command output to the ring network;
An abnormality detection unit for detecting an abnormality of the ring network;
A test apparatus, comprising: an abnormality processing unit that completes the command received from the control device after detecting an abnormality of the ring network without outputting the command to the ring network.   The abnormality detection unit detects an abnormality of a signal that is output to the ring network via the second interface and is to be returned to the second interface via each test unit on the ring network. The test apparatus according to claim 1, wherein an abnormality of the ring network is detected accordingly.   The abnormality detection unit is configured to output the clock signal indicating the command acquisition timing output to the ring network via the second interface in response to the fact that the clock signal is not input to the second interface. The test apparatus according to claim 2, wherein the abnormality is detected.   The abnormality detection unit has not returned the command output to the ring network via the second interface to the second interface via each test unit on the ring network. The test apparatus according to claim 2, wherein an abnormality of the ring network is detected accordingly. The second interface generates a dummy command at a predetermined time interval and outputs the dummy command to the ring network.
The abnormality detection unit detects an abnormality in the ring network in response to the dummy command not returning to the second interface via the test units on the ring network. The test apparatus described. Each of the plurality of test units outputs an acknowledge signal to the ring network in response to receiving the command destined for the test unit,
The ring network propagates the acknowledge signal in the opposite direction to the command and inputs it to the interface unit,
The second interface sequentially selects one test unit from the plurality of test units, and sequentially transmits the dummy commands destined for the test unit,
When the abnormality detection unit detects an abnormality in the ring network, the failure detection unit receives the acknowledge signal indicating that the dummy command has been received from the one test unit. The test apparatus according to claim 5, further comprising an abnormal point detection unit that detects that there is a problem in command transmission.

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