Error Code Detection Device and Error Code Detection Method

Abstract

The present invention can intuitively determine the reason for handshake failure. The data stream of the overall state transition including each state based on communication standards and the state transition conditions executed between the states is displayed as a state transition setting screen (11). When the handshake with the device under test ends, the state before the state transition failure and the failed state transition condition are emphasized and displayed in the state transition setting screen (11).

Description

Technical Field

[0001] The present invention relates to an error detection device and an error detection method for transmitting a known waveform as a test signal to a device under test in a state where the device under test is transitioned to a signal return state by a handshake based on a communication standard with the device under test, and detecting an error code of input data returned and received from the device under test accompanying the transmission of the test signal. Background Art

[0002] For example, the following method is generally adopted: Under the communication standard of a high-speed serial bus such as PCI Express and USB (Universal Serial Bus), when testing a receiver as a device under test, after performing a handshake that transitions the receiver to a test-specific signal return state (Loopback.Active), a known waveform for testing is input, and the bit error rate of the returned signal is confirmed.

[0003] When transitioning the device under test to the signal return state (Loopback.Active), a handshake type method of analyzing the signal of the device under test and performing a handshake for state transition based on the actual high-speed serial bus standard is well-known. As such a handshake type method, for example, as disclosed in Patent Document 1 below, a method is known in which a training waveform generated according to an instruction from a link state management unit is transmitted to the device under test to transition the link state of the LTSSM (Link Training & Status State Machine) of the device under test to loopback.

[0004] In this handshake type method, a function of displaying a record of the completed handshake is convenient, and a method of inputting and displaying the time staying in each state during the state transition is generally adopted. Moreover, when the device under test being verified fails in the state transition, the state causing the problem can be speculated based on the information of this record.

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-098615

[0006] However, in the method of displaying the record of the above handshake, when the handshake fails, in order to repeat the state transition, the record becomes lengthy, and there is a problem that it is difficult to trace the cause of the failure. Also, observing a simple state and a record composed of a list of residence times, in order to analyze why the state transition fails and which state transition condition is not satisfied and the reason for the handshake failure, a deep understanding of the communication standard is required. Moreover, there is a problem that a deep understanding of the communication standard and experience are required to adjust the state transition condition for this handshake failure. Summary of the Invention

[0007] Therefore, the present invention has been completed in view of the above problems, and an object thereof is to provide an error code detection device and an error code detection method capable of intuitively determining the reason for handshake failure.

[0008] In order to achieve the above object, in the error code detection device according to the first aspect of the present invention, in a state where the object under test W is transitioned to a signal return state through a handshake based on a communication standard, a test signal with a known waveform is transmitted to the object under test, and an error code of input data returned and received from the object under test along with the transmission of the test signal is detected. The error code detection device 1 is characterized by comprising:

[0009] An operation display unit 6 that displays a data flow of an overall state transition including each state based on the communication standard and state transition conditions executed between the states as a state transition setting screen 11; and

[0010] A display control mechanism 8a that controls the operation display unit in such a manner that the state before the state transition failure and the failed state transition condition are highlighted and displayed in the state transition setting screen when the handshake with the object under test ends.

[0011] The error code detection device according to the second aspect of the present invention is characterized in that, in the error code detection device according to the first aspect, it comprises:

[0012] A transition condition adjustment mechanism 8b that automatically adjusts the failed state transition condition and the state transition condition before the state transition failure within a prescribed setting range.

[0013] The error code detection device according to the third aspect of the present invention is characterized in that, in the error code detection device according to the second aspect,

[0014] "0" is input and set in the input box of the state transition condition 13A in the transmission state or the state transition condition 13B in the reception state.

[0015] The error code detection device according to the fourth aspect of the present invention is characterized in that, in the error code detection device according to the second aspect,

[0016] In the state transition setting screen, a state transition condition 13D that does not exist in the communication standard can be selected and set between states.

[0017] The error code detection method according to the fifth aspect of the present invention, in a state where the object under test W is transitioned to a signal return state through a handshake based on a communication standard, a test signal with a known waveform is transmitted to the object under test, and an error code of input data returned and received from the object under test along with the transmission of the test signal is detected. The error code detection method is characterized by further comprising the following steps:

[0018] Display the data stream of the overall state transition including each state based on the communication standard and the state transition conditions executed between the states as a state transition setting screen 11; and

[0019] When the handshake with the object under test ends, emphasize and display the state before the state transition failure and the failed state transition condition in the state transition setting screen.

[0020] The error code detection method according to aspect 6 of the present invention is characterized in that in the error code detection method of aspect 5,

[0021] Automatically adjust the failed state transition condition and the state transition condition before the state transition failure within a specified setting range.

[0022] The error code detection method according to aspect 7 of the present invention is characterized in that in the error code detection method of aspect 6,

[0023] Enter and set "0" in the input box of the state transition condition 13A in the transmission state or the state transition condition 13B in the reception state.

[0024] The error code detection method according to aspect 8 of the present invention is characterized in that in the error code detection method of aspect 6,

[0025] In the state transition setting screen, it is possible to select and set a state transition condition 13D that does not exist in the communication standard between states.

[0026] According to the present invention, the reason for the handshake failure can be intuitively determined based on the emphasized display content. And when the handshake fails, a successful handshake setting can be automatically performed even without special knowledge, so that advanced debugging can be carried out regardless of the user's understanding of the communication standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a block diagram of an error code detection device according to the present invention.

[0028] Figure 2 is a diagram showing a state transition setting screen when a handshake fails in the Polling.LFPS state in the error code detection device according to the present invention.

[0029] Figure 3 is a diagram showing a state transition setting screen when a handshake fails in the Polling.Active state in the error code detection device according to the present invention.

[0030] Figure 4This is a diagram showing a state transition setting screen for automatically adjusting the state transition conditions of handshake failure and achieving handshake success in the error detection device according to the present invention. Detailed implementation mode

[0031] Hereinafter, a mode for implementing the present invention will be described in detail with reference to the accompanying drawings.

[0032] The present invention relates, for example, to an error detection device and an error detection method using a handshake method in which a device equipped with a link training state machine (LTSSM: Link Training & Status State Machine) as a link state management mechanism for managing link states is used as a device under test under a communication standard of a high-speed serial bus such as PCI Express or USB, and the device under test is transitioned to a state (Loopback.Active) where a signal is returned through a handshake based on the communication standard with the device under test. In addition, the LTSSM exists in the physical layer and transitions by observing the signals received by the physical layer.

[0033] Moreover, in the error detection device and the error detection method according to the present invention, in a measurement mode of transitioning to a state (Loopback.Active) where a signal is returned, a test signal with a known waveform is sent to the device under test, and bit errors of the input data returned and received from the device under test along with the transmission of the test signal are detected.

[0034] The device under test W, which is the detection object of the error detection device 1 of the present embodiment, is equipped with an LTSSM (Wa) for managing link states. In a training mode of handshake based on the communication standard before error detection (before error measurement), it is connected to the error detection device 1 via a test fixture (not shown), and the detection of this connection starts the transmission of an LFPS (Low Frequency Periodic Signaling) signal.

[0035] In addition, since the interfaces of the signal output unit of the error detection device 1 and the signal receiving unit of the device under test W are different, the test fixture (not shown) is used for conversion to make these interfaces consistent.

[0036] As Figure 1 shown, the error detection device 1 of the present embodiment is generally configured to include a waveform generation unit 2, a waveform detection unit 3, an error detection unit 4, a link state management unit 5, an operation display unit 6, a storage unit 7, and a control unit 8.

[0037] The waveform generation unit 2 generates a waveform to be transmitted to the device under test W. In a training mode for transitioning the LTSSM (Wa) of the device under test W to a signal return state (Loopback.Active), a training waveform signal corresponding to the link state of the LTSSM is generated through control from the control unit 8 via the link state management unit 5.

[0038] In a measurement mode for performing a jitter tolerance test on the device under test W in a state where the device under test W has transitioned to a signal return state (Loopback.Active), the waveform generation unit 2 generates a known waveform signal input to the device under test W through control from the control unit 8 via the link state management unit 5. The known waveform signal at this time is composed of, for example, a pseudo-random binary sequence based on NRZ (Non Return to Zero) signals of "0" and "1", and is a CP (Compliance pattern: test pattern) of a waveform defined by a communication standard.

[0039] In the training mode, the waveform detection unit 3 detects the training waveform signal transmitted from the device under test W according to the transition of the state of the LTSSM (Wa) of the device under test W, along with the handshake based on the training waveform signal transmitted from the waveform generation unit 2.

[0040] In the measurement mode in a state where the device under test W has transitioned to a signal return state (Loopback.Active), when the waveform signal generated by the waveform generation unit 2 is input to the device under test W, the waveform detection unit 3 detects the waveform signal that returns from the device under test W and is input along with this.

[0041] In the measurement mode, the error detection unit 4 compares the known waveform signal generated by the waveform generation unit 2 as a test signal with the waveform signal that returns from the device under test W and is detected by the waveform detection unit 3 along with the transmission of the known waveform signal to detect bit errors.

[0042] The link state management unit 5 includes an LTSSM having the same or equivalent mechanism as the LTSSM (Wa) mounted on the device under test W, and operates according to the communication standard of the I / O interface used (for example, USB3.2 Gen1, USB3.2 Gen2, etc.).

[0043] The link state management unit 5 transitions the state of the link in the same manner as the LTSSM (Wa) of the device under test W based on the signal communicated with the device under test W, and can identify the current link state of the LTSSM (Wa) in the device under test W. Thereby, various information such as the LTSSM value, link speed, presence or absence of loopback, transition waveform of the LTSSM, channel number for identifying the channel, link number, occurrence time or occurrence count of the waveform signal, weighting amount, and adjustment value of the equalizer on the receiving side can be obtained.

[0044] The operation display unit 6 is a user interface including a display unit such as a liquid crystal display and various keys, switches, buttons, and soft keys on the display screen of the display unit provided in the error detection device 1, and is operated when performing various settings or displays related to error detection.

[0045] Specifically, the operation display unit 6 displays, under the control of the control unit 8 based on the operation of the operation unit, a setting screen related to error detection, recorded information stored in the storage unit 7, measurement results of error information detected by the error detection unit 15, and the like.

[0046] Moreover, as a display related to the state transition based on the handshake with the device under test W, the operation display unit 6, under the control of the control unit 8 based on the operation of the operation unit, Figures 2 to 4 displays the state transition setting screen 11 in the display mode shown on the display screen 6a.

[0047] In the state transition setting screen 11, a data flow graph of the overall state transition including each state (elliptical part showing the name of each state) 12 based on the communication standard and the state transition conditions (rectangular part showing the state transition conditions) 13 executed between the states is displayed on the display screen.

[0048] For example, in Figure 2 the state transition setting screen 11, each state 12 is displayed in the state transition order of "Rx.Detect" → "Polling.LFPS" → "Polling.RxEQ" → "Polling.Active" → "Polling.Configuration" → "Polling.Idle" → "Loopback.Active" from top to bottom of the screen.

[0049] Moreover, in Figure 2In the state transition setting screen 11, as the state transition condition 13 executed between states, the state transition condition 13A of the transmission state (PPG Condition) is displayed on the left side of each state 12, the state transition condition 13B of the reception state (ED Condition) is displayed on the left side of 13A, and the state transition condition 13C of the timeout setting (TimeoutSetting[ms]) is displayed on the right side of each state 12.

[0050] Specifically, in Figure 2 the state transition setting screen 11, for the state transition condition 13A of the transmission state, "Sent

[16] bursts LFPS", "Sent[4]bursts LFPS", "Sent[65,536]TSEQ", "Sent

[16] TS1OS", "Sent

[16] TS2 OS" match it. For the state transition condition 13B of the reception state, "Received DUT’sLFPS", "Received[2]LFPS", "Received[8]TS1 / TS2 OS", "Received[8]TS2 OS" match it. For the state transition condition 13C of the timeout setting, the

[360] , [12.0], [12.0], [2.0], [2.0] between "Polling.LFPS", "Polling.RxEQ", "Polling.Active", "Polling.Configuration", "Polling.Idle" and "Rx.Detect" respectively match it.

[0051] In addition, the [] of the above-mentioned state transition condition 13A of the transmission state, state transition condition 13B of the reception state, and state transition condition 13C of the timeout setting respectively correspond to the input box 13a described below, and the numbers in the [] indicate the values set and input into the input box 13a.

[0052] Figure 2 The state transition condition 13 (the state transition condition 13A of the transmission state, the state transition condition 13B of the reception state, the state transition condition 13C of the timeout setting) for each input box 13a can be variably input and set within a specified adjustment range including the values specified by the communication standard. Thus, it is not limited to the fixed values specified by the communication standard, and more delicate input settings can be made.

[0053] For example, in Figure 2In the state transition setting screen 11, the state transition condition 13B for the received state: "Received[8]TS1 / TS2 OS" means that after continuously receiving TS1 or TS2 eight times in the state of "Polling.Active", the transition to the next state is made. However, the user can input and set any value within the range of "from 0 to 65535" in the input box 13a, including the value "8" currently input in the input box 13a as a value specified by the communication standard.

[0054] Moreover, as a setting of 0, as long as "0" is input and set in the input box 13a of the state transition condition 13A in the sending state or the state transition condition 13B in the received state, the state transition condition can be skipped and the transition to the next state transition condition or the next state can be made. Thus, even in the case of a handshake failure with the object under test W, including the failed state transition condition, by setting 0 for the subsequent state transition conditions, the transition to the state of "Loopback.Active" can be made quickly.

[0055] In addition, when a handshake is performed with the object under test W, in the input box 13a of each state transition condition 13, the value specified by the communication standard of the object under test W or the value at the last handshake with the object under test W is set as the initial value.

[0056] In the state transition setting screen 11, a state transition condition 13D that does not exist in the communication standard can be selected and set between states. For example, in Figure 2 or Figure 3 In the state transition setting screen 11, in the state of "Polling.Active", the state transition condition 13A for the sending state after continuously receiving TS1 or TS2 eight times: "Sent

[16] TS1 OS" corresponds to the state transition condition 13D that does not exist in the communication standard. A check box 13b is provided in the state transition condition 13D that does not exist in the communication standard, and the effective / invalid switching is performed according to whether the check box 13b is checked. Thus, as long as the desired value is set and input in the input box 13a in the state where the check box 13b of the state transition condition 13D that does not exist in the above communication standard is checked, the time in the state of "Polling.Active" can be extended and the timing can be adjusted.

[0057] In addition, in Figures 2 to 4In the state transition setting screen 11, a state transition condition 13D that does not exist in the communication standard is added between the state transition condition "Received DUT’s LFPS" in the receiving state and the state "Polling.LFPS", which is "Transition Delay[1]ms", but it is not limited to this. The state transition condition 13D that does not exist in this communication standard can be appropriately added to the position where the state with difficult timing adjustment exists for each communication standard.

[0058] Moreover, when the handshake between the operation display unit 6 and the DUT W ends, in Figure 2 or Figure 3 In the state transition setting screen 11, through the control of the display control mechanism 8a of the control unit 8 described later, the highest reached state and the state transition conditions that failed between the highest reached state and the immediately following state are emphasized and displayed. In addition, the highest reached state here refers to the state before the state transition fails.

[0059] As a specific method of emphasized display, for example, it is displayed in red to make the highest reached state at the end of the handshake and the state transition conditions that failed between the highest reached state and the immediately following state conspicuous. In contrast, for example, the reached states and the successful state transition conditions are displayed in green, and the un-reached states and state transition conditions other than these are displayed in gray.

[0060] Here, Figure 2 The state transition setting screen 11 when the handshake fails in the state of "Polling.LFPS" is shown, Figure 3 The state transition setting screen 11 when the handshake fails in the state of "Polling.Active" is shown.

[0061] In addition, in Figure 2 or Figure 3 In the state transition setting screen 11, the highest reached state at the end of the handshake and the state transition conditions that failed between the highest reached state and the immediately following state are represented by thick lines, the states and state transition conditions that have been successfully reached at the end of the handshake are represented by thin lines, and the un-reached states and state transition conditions other than these are represented by dotted lines.

[0062] Figure 2 The state transition setting screen 11 of shows the following situation: as shown by the thick line, the highest reached state at the end of the handshake is "Polling.LFPS". In this state of "Polling.LFPS", the state transition condition of the receiving state: "Received[2]LFPS" cannot be satisfied, and after the state transition condition of the timeout setting, which is [360ms], it returns to the state of "Rx.Detect".

[0063] That is, Figure 2 The state transition setting screen 11 of Figure 2 shows the following situation: in the state of "Polling.LFPS", if LFPS is received continuously twice, the state transition condition of the reception state is satisfied. After the state transition condition of the transmission state, that is, after transmitting LFPS 16 times, it is possible to transition to the next state of "Polling.RxEQ", but the state transition condition of the reception state at this time cannot be satisfied.

[0064] Moreover, in Figure 2 In the failure example of the handshake of Figure 2 , it can be speculated that there may be a problem in the LFPS output of the device under test W. In this case, if the set value [2] of the input box 13a for the state transition condition of the reception state: "Received[2]LFPS" is set to [0], the state transition condition of this reception state is ignored, and thus it is possible to transition to the next state after transmitting LFPS 16 times.

[0065] And, Figure 3 The state transition setting screen 11 of Figure 3 shows the following situation: as shown by the thick line, the highest state reached at the end of the handshake is "Polling.Active". In this state of "Polling.Active", the state transition condition of the reception state: "Received[8]TS1 / TS2 OS" cannot be satisfied, and after the state transition condition set by the timeout, that is, [12.0ms], it returns to the state of "Rx.Detect".

[0066] That is, Figure 3 The state transition setting screen 11 of Figure 3 shows the following situation: in the state of "Polling.Active", if TS1 or TS2 is received continuously 8 times, the state transition condition of the reception state is satisfied. After the state transition condition of the transmission state, that is, after transmitting TS1 OS 16 times, it is possible to transition to the next state of "Polling.Configuration", but the state transition condition of the reception state at this time cannot be satisfied.

[0067] Moreover, in Figure 3 In the failure example of the handshake of Figure 3 , it can be speculated that there may be a problem in the timing or waveform quality of the TS1 or TS2OS output of the device under test W.

[0068] In addition, in Figure 2 or Figure 3In the state transition setting screen 11 at the time of handshake failure, during the actual link training, several handshakes are performed and repeated failures occur, but the state that reaches the highest level at the end of the handshake and the state transition conditions for failure between the state immediately following it are emphasized and displayed. For example, even if the state transitions to "Polling.Active" during the first handshake and times out, and then the handshake ends with cycling between the states of "Polling.LFPS" and "Rx.Detect", the state of "Polling.Active" that reaches the highest level at the end of the handshake and the state transition conditions for failure between the state of "Polling.Configuration" immediately following it are emphasized and displayed.

[0069] Moreover, since the operation display unit 6 automatically adjusts the state transition conditions through the transition condition adjustment mechanism 8b of the control unit 8 described later, as Figures 2 to 4 shown, through the control of the control unit 8, a check box 14 for the automatic adjustment mode: "Auto tune" is displayed in the state transition setting screen 11, and the effective / invalid switching of the automatic adjustment mode is performed according to whether the check box 14 is checked.

[0070] The storage unit 7 stores, through the control of the control unit 8, for example, the transition destination of the link state, the occurrence time of the transition, the trigger of the transition, and error information managed by the link state management unit 5 as record information corresponding to the transition state of the LTSSM.

[0071] When performing a handshake or error code detection with the object under test W, the control unit 8 centrally controls each unit (link state management unit 5, operation display unit 6, storage unit 7).

[0072] Specifically, in the training mode, the control unit 8 issues an instruction to the waveform generation unit 2 via the link state management unit 5 in such a way as to generate the next training waveform signal according to the current link state of the LTSSM of the link state management unit 5.

[0073] Furthermore, in the measurement mode, the control unit 8 issues an instruction to the waveform generation unit 2 via the link state management unit 5 in such a way as to generate a waveform signal.

[0074] Moreover, the control unit 8 includes a display control mechanism 8a and a transition condition adjustment mechanism 8b. The display control mechanism 8a controls the reading of the record information corresponding to the transition state of the LTSSM of the link state management unit 5 or the detection result of the error detection unit 4, and performs the display control of the read record information or detection result to the operation display unit 6 or Figures 2 to 4 the display control of the state transition setting screen 11 shown.

[0075] The transition condition adjustment mechanism 8b determines the state transition conditions for handshake failure based on the recorded information corresponding to the transition state of the LTSSM of the link state management unit 5. When the check box 14 of the automatic adjustment mode: "Auto tune" on the state transition setting screen 11 for Figures 2 to 4 is checked, for the state transition conditions at the end of the handshake that fail and the state transition conditions before that, the set values are automatically adjusted within a specified adjustment range (the adjustment range preset by the user, or the adjustment range starting from the value specified by the communication standard).

[0076] Specifically, in the case of handshake failure in Figure 3 , based on the recorded information of the link state management unit 5, the state transition condition for the receive state: "Received[8]TS1 / TS2 OS" and the state transition condition for the transmit state: "Sent[65,536]TSEQ" are determined as the state transition conditions for failure at the end of the handshake. As Figure 4 shown, the set value in the input box 13a for the state transition condition "Received[8]TS1 / TS2 OS" input to the receive state is finally automatically adjusted from [8] to [6]. And, as Figure 4 shown, the set value in the input box 13a for the state transition condition "Sent[65,536]TSEQ" input to the previous transmit state is finally automatically adjusted from [65,536] to [54,650].

[0077] Then, when a handshake is performed between the error detection device 1 and the device under test W configured as above, the error detection device 1 and the device under test W are connected via a test fixture (not shown).

[0078] If the device under test W detects a connection with the error detection device 1 via the test fixture, it starts sending the LFPS signal as a training waveform signal.

[0079] The error detection device 1 transitions to the Polling.LFPS state triggered by the reception of the LFPS signal sent from the device under test W, and starts sending the LFPS signal as a training waveform signal.

[0080] The device under test W transitions to the next state triggered by the reception of the LFPS signal sent from the error detection device 1, and sends the training waveform signal corresponding to the next state.

[0081] Then, when the handshake between the device under test W and the error detection device 1 is successful, they send the training waveform signals defined in their respective states and transition states. The LTSSM of the device under test W finally transitions to the Loopback.Active state for testing.

[0082] When the handshake between the DUT W and the error code detection device 1 ends as described above, the display control mechanism 8a of the control unit 8 controls the operation display unit 6 to graphically display the data flow of the overall state transition including each state based on the communication standard and the state transition conditions executed between the states on the state transition setting screen 11.

[0083] Then, when the handshake between the DUT W and the error code detection device 1 fails and does not transition to the Loopback.Active state, as Figure 2 or Figure 3 shown by the thick lines, the highest reached state and the state transition conditions that failed between the state and the immediately following state are emphasized and displayed.

[0084] At this time, if the check box 14 of the automatic adjustment mode: "Auto tune" on the state transition setting screen 11 is checked and the handshake is executed again, the transition condition adjustment mechanism 8b of the control unit 8 automatically adjusts the set values of the state transition conditions that failed at the end of the previous handshake and the state transition conditions before that within a specified adjustment range.

[0085] In addition, when the handshake between the DUT W and the error code detection device 1 fails and does not transition to the Loopback.Active state, on the Figure 2 or Figure 3 state transition setting screen 11, the values set in the input boxes 13a of the state transition conditions 13 (the state transition condition 13A of the transmission state, the state transition condition 13B of the reception state, the state transition condition 13C of the timeout setting) that may cause the handshake to fail can be adjusted, and the handshake can be executed again with the DUT W.

[0086] Moreover, when there is a state for which it is difficult to perform timing adjustment according to the communication standard, it is also possible to check the check box 13b of the state transition condition 13D that does not exist in the communication standard and set and input the desired value in the input box 13a.

[0087] In the above embodiment, as Figure 1 shown, it is assumed that the error code detection device 1 integrally includes a waveform generation unit 2, a waveform detection unit 3, an error detection unit 4, a link state management unit 5, an operation display unit 6, a storage unit 7, and a control unit 8, but it is not limited to this structure. For example, it can be composed of an external device such as a personal computer to which the operation display unit 6 is connected, or the operation display unit 6 can be composed of a module in which the display unit and the operation part are separated, or the waveform generation unit 2 and the waveform detection unit 3 can be modularized separately or set as separate boxes.

[0088] Thus, according to this embodiment, as a debugging function different from the original handshake input function, the data stream of the overall state transition including each state based on the communication standard and the state transition condition 13 executed between the states is displayed as a state transition setting screen 11 based on graphical display. When the handshake with the device under test W ends, the highest reached state and the state transition condition that failed between the state and the immediately following state are highlighted and displayed in the state transition setting screen 11. Thus, the reason for the handshake failure can be intuitively determined based on the highlighted content.

[0089] Moreover, when the handshake is executed again with the check box 14 of the automatic adjustment mode: "Auto tune" of the state transition setting screen 11 checked, the state transition condition that failed at the end of the previous handshake and the state transition condition before it are automatically adjusted for the set value within a specified adjustment range by the transition condition adjustment mechanism 8b of the control unit 8. Thus, when the handshake fails, the setting for a successful handshake can be automatically performed even without special knowledge, enabling advanced debugging without depending on the user's understanding of the communication standard.

[0090] Furthermore, in the state transition setting screen 11, the value input to the input box 13a of the state transition condition 13 defined by the communication standard is not a fixed value but has an adjustment range. Also, in the state transition setting screen 11, the state transition condition 13D that does not exist in the communication standard can be selectively added by checking the check box 13b. Thus, it combines the advantages of both the fixed sequence type and the handshake type, enabling a flexible and easy standard test. As a result, the user can accurately grasp the trend of the state transition or the characteristics of the malfunction of the device under test, enabling smooth development and debugging.

[0091] The preferred embodiments of the error detection device and the error detection method according to the present invention have been described above, but the present invention is not limited to the descriptions and drawings based on this embodiment. That is, it is obvious that other embodiments, examples, application techniques, etc. implemented by those skilled in the art based on this embodiment are included in the scope of the present invention.

[0092] Symbol Explanation

[0093] 1 - Error detection device, 2 - Waveform generation section, 3 - Waveform detection section, 4 - Error detection section, 5 - Link state management section, 6 - Operation display section, 7 - Storage section, 8 - Control section, 8a - Display control mechanism, 8b - Transition condition adjustment mechanism, 11 - State transition setting screen, 12 - State (name of the state), 13 - State transition condition, 13A - State transition condition for the transmission state, 13B - State transition condition for the reception state, 13C - State transition condition for timeout setting, 13D - State transition condition not present in the communication standard, 13a - Input box, 13b - Check box, 14 - Check box, W - Object under test, Wa - LTSSM.

Claims

1. An error code detection device that, in a state where the device under test (W) is transitioned to a signal return state through a handshake based on a communication standard between the device and the device under test, sends a test signal with a known waveform to the device under test, and detects an error code in the input data returned and received from the device under test along with the transmission of the test signal. The error code detection device (1) is characterized by comprising: An operation display unit (6) that displays a data stream of the overall state transition including each state based on the communication standard and the state transition conditions executed between the states as a state transition setting screen (11); and A display control mechanism (8a) that controls the operation display unit in such a manner that, when the handshake with the device under test ends, the state before the state transition failure and the failed state transition conditions are emphasized and displayed in the state transition setting screen.

2. The error code detection device according to claim 1, wherein: Comprising: A transition condition adjustment mechanism (8b) that automatically adjusts the failed state transition condition and the state transition condition before the state transition failure within a specified setting range.

3. The error code detection device according to claim 2, wherein: Input and set "0" in the input box for the state transition condition (13A) in the transmission state or the state transition condition (13B) in the reception state.

4. The error code detection device according to claim 2, wherein: On the state transition setting screen, it is possible to select and set a state transition condition (13D) that does not exist in the communication standard between states.

5. An error code detection method that, in a state where the device under test (W) is transitioned to a signal return state through a handshake based on a communication standard between the device and the device under test, sends a test signal with a known waveform to the device under test, and detects an error code in the input data returned and received from the device under test along with the transmission of the test signal. The error code detection method is characterized by further comprising the following steps: Displaying a data stream of the overall state transition including each state based on the communication standard and the state transition conditions executed between the states as a state transition setting screen (11); and When the handshake with the device under test ends, emphasizing and displaying the state before the state transition failure and the failed state transition conditions in the state transition setting screen.

6. The error code detection method according to claim 5, wherein: Including the following steps: Automatically adjust the failed state transition condition and the state transition condition before the state transition failure within a specified setting range.

7. The error code detection method according to claim 6, wherein: Input and set "0" in the input box for the state transition condition (13A) in the transmission state or the state transition condition (13B) in the reception state.

8. The error code detection method according to claim 6, wherein: On the state transition setting screen, it is possible to select and set a state transition condition (13D) that does not exist in the communication standard between states.

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