JP6271942B2 - Electronic device and test method - Google Patents

Description

  The present invention relates to an electronic device and a test method thereof.

  Patent Document 1 discloses a method of starting a computer that performs a self-diagnosis test. In the activation method of Patent Document 1, the computer is activated after confirming whether the self-diagnosis test is normally performed. In the self-diagnosis test, the output code of the computer during the self-diagnosis test is compared with the output code during normal operation.

  By the way, in an electronic device using a circuit such as a memory or an LSI, it is required to stably supply a driving voltage (power supply voltage). Patent Document 2 discloses a power supply device that lowers a target value in a stepwise manner when a deviation between a DC / DC converter output voltage and a target value exceeds a range defined by an upper limit and a lower limit.

JP 2005-321949 A JP 2011-166923 A

  In the starting method of Patent Document 1, since a self-diagnosis test is performed by comparing output codes, it is difficult to supply an appropriate drive voltage. In the power supply device of Patent Document 2, it is difficult to set an appropriate voltage.

  The present invention has been made in view of the above problems, and provides an electronic device and a test method that can be more appropriately tested.

  An electronic device according to an aspect of the present invention includes a target circuit that is a target of a check test, a control unit that performs a check test by comparing input data and output data for the target circuit, and a check test result is abnormal. A voltage control unit that changes a drive voltage supplied to the target circuit, and the control unit performs the check test of the target circuit after the voltage control unit changes the drive voltage. It is.

  A test method for an electronic device according to one aspect of the present invention performs a check test by comparing input data and output data for a target circuit, and supplies the target circuit when the check test result is abnormal. The drive voltage to be changed is changed, and after the drive voltage is changed, the check test of the target circuit is performed.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic device which can be tested more appropriately, and a test method can be provided.

1 is a block diagram showing a configuration of an electronic device according to a first exemplary embodiment. 3 is a flowchart showing a test method according to the first exemplary embodiment; It is a graph which shows a voltage fluctuation and a normal voltage range. FIG. 6 is a block diagram illustrating a configuration of an electronic device according to a second embodiment.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

  First, the background leading to the present invention will be described. When a read / write access error occurs in the self-check test, the fact that the core voltage (drive voltage) supplied to the memory unit 12 occupies most of the error factors is based on empirical rules in the development of electronic devices. As a specific example, let us consider a case where an error occurs in read / write access of the self-check test when the maximum possible drive voltage is 3.365 V in a 3.3 V drive memory. When an error is confirmed here, in many cases, the control is performed to supply the maximum value capable of driving the supply voltage, and then the problem is solved by confirming again by the memory check test. In addition, the optimum value as the drive voltage of the device varies depending on the individual due to the influence of the manufacturing process. For this reason, by setting and controlling a voltage value that can be operated at a minimum, it is possible to operate with an optimum voltage unique to the target device. Therefore, by making it applicable to parts that have been treated as defective so far, there is an effect of improving productivity, suppressing power consumption of electronic devices, and extending life.

  The electronic device according to the present embodiment performs a self-check test at startup. An electronic apparatus according to this embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of an electronic device. The electronic device 10 includes a control IC unit 11, a memory unit 12, and a voltage control unit 13. Here, a target circuit to be tested is a memory unit such as a DRAM (Dynamic Random Access Memory) or a DDR (Double Data Rate) memory. It may be an LSI (Large Scale Integration) such as an integrated circuit.

  The control IC unit 11 includes a CPU (Central Processing Unit) and the like, and is a control unit that controls the electronic device 10 in an integrated manner. That is, the control IC unit 11 controls the memory unit 12 and the voltage control unit 13. In addition, the control IC unit 11 outputs a self-check test instruction signal 101 for performing a self-check test of the memory unit 12 to the memory unit 12. For example, when the electronic device 10 is activated, the control IC unit 11 issues a test instruction to the memory unit 12 using the self-check test instruction signal 101. The control IC unit 11 accesses the memory unit 12 using the self-check test instruction signal 101. The memory unit 12 transmits a check signal 102 to the control IC unit 11 as to whether or not normal access is possible.

  For example, read / write access to an arbitrary address is performed between the control IC unit 11 and the memory unit 12 using a terminal such as a port that the control IC unit 11 originally has as a function. The control IC unit 11 compares the write data to be written to the memory unit 12 with the read data to be read from the memory unit 12 and performs a check test. If the read data and the write data match, it is determined to be normal, and if they do not match, it is determined to be abnormal. As described above, the self-check test can be performed by comparing the input data and the output data for the memory unit 12.

  The voltage control unit 13 outputs the drive voltage 103 to the memory unit 12. The memory unit 12 operates based on the drive voltage 103. The voltage control unit 13 controls the drive voltage supplied to the memory unit 12.

  The voltage control unit 13 outputs the drive voltage 103 as the monitoring voltage 104 to the control IC unit 11. The control IC unit 11 measures the monitoring voltage 104 at regular time intervals. For example, the drive voltage is measured using an A / D input terminal of the control IC unit 11.

  Then, the control IC unit 11 determines whether or not the monitoring voltage 104, that is, the drive voltage 103 is normal. For example, it is determined whether or not the monitoring voltage 104 is within the normal voltage range. The normal voltage range is defined by a preset upper limit value and lower limit value.

  The control IC unit 11 outputs a control signal 105 to the voltage control unit 13 based on the test result of the self-check test. Further, the control IC unit 11 outputs a control signal 105 to the voltage control unit 13 based on the measurement result of the monitoring voltage 104. The voltage control unit 13 controls the drive voltage 103 based on the control signal 105. That is, the voltage control unit 13 that has received the control signal 105 sets a power supply voltage value to be supplied to the memory unit 12 in accordance with the content of the instruction of the control signal 105.

  For example, when the test result of the self-check test is abnormal, the control IC unit 11 outputs the control signal 105 to the voltage control unit 13 in order to change the drive voltage 103 to an appropriate value. Alternatively, when the monitoring voltage 104 is outside the normal voltage range, the control IC unit 11 outputs the control signal 105 to the voltage control unit 13 in order to change the drive voltage 103 to an appropriate value. If the measured voltage value is outside the specified normal voltage range, an adjustment instruction can be given by the control signal 105 so as to approach an appropriate value that falls within the specified range. Thus, the voltage control unit 13 can supply the appropriate drive voltage 103 to the memory unit 12.

  Next, a test method executed when the electronic device 10 is powered on will be described with reference to FIG. FIG. 2 is a flowchart illustrating a test method for the electronic device 10.

  First, the user turns on and activates the electronic device 10 (S1). Then, the control IC unit 11 performs a self-check test (S2). That is, the read / write access confirmation to the memory unit 12 is started. Then, the control IC unit 11 determines whether or not the self-check test result is normal based on the comparison result between the read data and the write data (S3). That is, based on the read data read from the memory unit 12, it is determined whether the memory unit 12 is normal or abnormal. If the self-check test result is normal (YES in S3), it is determined that the electronic device 10 has started up normally, and the process ends normally. That is, the electronic device 10 is shifted to normal operation.

  If the self-check test result is abnormal (NO in S3), it is determined whether the number of executions of the self-check test is equal to or less than a threshold value N (S4). Note that the threshold value N can be an arbitrarily set value of 2 or more. If the number of tests is greater than N (NO in S4), it is determined as an error and the process ends abnormally. That is, it is determined that the electronic device 10 is an abnormal product (defective product).

  When the number of self-check tests is N or less (YES in S4), the control IC unit 11 measures the monitoring voltage 104 (S5). Then, the control IC unit 11 determines whether or not the measurement voltage is normal (S6). That is, the control IC unit 11 determines whether or not the measured voltage is within the normal voltage range. Then, the control IC unit 11 outputs a control signal 105 corresponding to the measured voltage to the voltage control unit 13.

  When the measured voltage is normal (YES in S6), the boost control is performed up to the maximum drivable voltage (S7). The maximum drivable voltage is the highest drive voltage that can be supplied by the voltage control unit 13, and normally has a voltage value higher than the upper limit of the normal voltage range. The maximum drivable voltage may be set in advance. As described above, when the self-check test result with the drive voltage in the normal voltage range is abnormal, the voltage control unit 13 supplies the memory unit 12 with the maximum drive voltage 103 that can be supplied in a circuit.

  On the other hand, if the measured voltage is not normal (NO in S6), the voltage is controlled within the normal voltage range (S8). For example, as shown in FIG. 3A, when the drive voltage 103 is higher than the upper limit of the normal voltage range, the voltage level is lowered to the upper limit. Also, as shown in FIG. 3B, when the drive voltage 103 is lower than the lower limit of the normal voltage range, the voltage level is increased to the lower limit. Thereby, a power supply voltage fall can be prevented and quality can be ensured by stabilizing the operation of the electronic device 10.

  In this way, the voltage control unit 13 controls the drive voltage 103. When voltage control is performed in S7 or S8, the voltage control unit 13 outputs the response signal 106 to the memory unit 12. If voltage control is performed in S7 or S8, a self-check test is executed as in S2 (S9). If a self-check test is performed in S2 or S9, the number of executions is incremented.

  Then, similarly to S3, it is determined whether or not the self-check test result is normal (S10). When the self-check test result is normal (YES in S10), the drive voltage is stepped down (S11). Here, the drive voltage is lowered by a predetermined value. Then, returning to S9, a self-check test is performed. That is, the processes of S9 to S11 are repeatedly executed. By doing so, the drive voltage 103 can be changed step by step. That is, the drive voltage 103 can be gradually lowered.

  If it is determined in S10 that the test result is not normal (NO in S10), it is determined whether or not the previous self-check test result is normal (S12). That is, it is determined whether the self-check test result before the drive voltage 103 is lowered by one step is normal. In this way, the drive voltage is gradually lowered from the normal drive voltage at which the self-check test result is normal, and an abnormal drive voltage at which the self-test result becomes abnormal is obtained. In other words, the boundary between the normal drive voltage at which the self-check test result is normal and the abnormal drive voltage at which the self-check test result is abnormal can be obtained.

  If the previous self-check test result is abnormal (NO in S12), the process returns to step S4. That is, when the self-check test result is abnormal continuously, the process returns to step S4, and it is determined whether or not the number of self-check test executions is N or less. When the number of executions is N or less (NO in S4), the self-check test is performed again with the maximum driveable voltage (S7) or the drive voltage (S8) in the normal voltage range (S9). On the other hand, if the self-check test result becomes abnormal (N + 1) continuously (NO in S4), the process ends abnormally. As described above, when the self-check test result becomes abnormal (N + 1) times, the electronic device 10 is determined to be an abnormal product, and the process ends.

  When the previous self-check test result is normal (YES in S12), the drive voltage is controlled to the previous set voltage (S13). In other words, the voltage control unit 13 supplies the normal drive voltage with a normal self-check test result as the drive voltage 103 to the memory unit 12. In this way, the normal drive voltage closest to the boundary between the normal drive voltage and the abnormal drive voltage is supplied to the memory unit 12. Then, a self-check test is performed with the normal drive voltage 103 (S14). It is determined whether the self test check test is normal (S15).

  If the self-check test is normal (YES in S15), the process ends normally. That is, the normal driving voltage 103 is set, and the electronic device 10 shifts to a normal operation. By doing in this way, the lower drive voltage 103 can be set and power consumption can be suppressed. On the other hand, if the self-check test is not normal (NO in S15), the process ends abnormally. In this case, when the self-check test is performed again with the drive voltage 103 once the self-check test result is normal, the test result is abnormal. For this reason, it is determined that there is an abnormal factor other than the drive voltage 103, and the electronic device 10 is determined to be an abnormal product (defective product).

  With the above processing, a normal drive voltage at which the self-check test result is normal can be obtained. It is possible to reduce component defects due to read / write access errors in the self-check test of the memory unit 12 as the target circuit. Therefore, the production yield can be reduced and the productivity can be improved. By performing a self-check test at the time of power activation without greatly changing the scale of the electronic device 10, it can be realized with a simple structure.

  The present embodiment is characterized by having a self-check test function, a power supply voltage measurement function, and a power supply voltage set value control function when the electronic device 10 is activated. Using these configurations, it is possible to provide the electronic device 10 that always operates with stable quality. For example, voltage control is performed based on the test result of the self-check test and the measurement result of the drive voltage 103. Thereby, stable voltage supply can be performed at an optimum driving voltage value for each individual. For example, even when there is a variation in the driveable voltage value for each electronic device due to the influence of the manufacturing process, an appropriate drive voltage can be set for each individual.

  Furthermore, even when there are individual differences in the normal drive voltage, the number of electronic devices 10 that are excluded as defective products can be reduced. Therefore, the yield in manufacture of the electronic device 10 can be improved, and productivity can be improved.

  Furthermore, even when the drive voltage value to be supplied is arbitrarily set in the circuit of the electronic device 10, the function can be easily realized. Therefore, it is not necessary to involve a large-scale structural change. The reason is that a control function can be added by using a function that is normally mounted on the control IC unit 11 such as a CPU inside the circuit of the electronic device 10 without changing the appearance. For example, voltage measurement can be performed using an A / D converter (not shown) built in the control IC unit 11. Therefore, stable quality can be realized with a simple configuration. Further, as described above, it is only necessary to change the function in the circuit of the electronic device 10, and therefore, the design of the apparatus is not affected at all when the function for realizing the present invention is added.

  Moreover, it is possible to appropriately test even under the influence of noise components. For example, even if the drive voltage 103 falls outside the normal voltage range due to noise, the self-check test is performed within the normal voltage range. It is possible to reduce the case where the product is judged to be defective due to access failure and discarded. Therefore, it is possible to provide a circuit that realizes improvement in productivity and has stable operation quality with an optimum driving voltage for each individual. Furthermore, even when the optimum drive voltage changes due to aging, the drive voltage 103 can be optimized by performing a test at the time of startup. Thereby, lifetime improvement of an electronic device can be achieved.

  As described above, in the electronic device 10 and the check method according to the present embodiment, the self-check test result is abnormal. The voltage control unit 13 changes the drive voltage 103. The voltage controller 13 changes the drive voltage until the check test result is normal. Thereby, while being able to set an appropriate drive voltage, the number of the electronic devices 10 determined to be defective can be reduced. Therefore, productivity can be improved.

  Furthermore, when the self-check test result becomes abnormal after exceeding N times, the electronic device 10 is determined as an error. By doing so, it is possible to appropriately determine an error. For example, when the number of times the drive voltage 103 is changed stepwise exceeds the threshold N, the electronic device 10 is determined to be in error. By doing so, it is possible to discriminate between a non-defective product and a defective product without excessively increasing the number of tests. Therefore, the non-defective product determination of the electronic device 10 can be performed appropriately, and the productivity can be improved.

  Further, the voltage control unit 13 gradually changes the drive voltage 103 to obtain a boundary between the abnormal drive voltage at which the check test result is abnormal and the normal drive voltage at which the test result is normal. The normal drive voltage that is the drive voltage and is closest to the boundary is set as the operating voltage. That is, it is possible to operate at the lowest drive voltage at which normal operation is possible. Thereby, normal operation can be performed with a lower drive voltage, and power consumption can be suppressed.

Embodiment 2. FIG.
The electronic device 10 according to the second embodiment will be described with reference to FIG. 4. FIG. 4 is a block diagram illustrating the configuration of the electronic device 10. The electronic device 10 includes a target circuit 14, a control unit 15, and a voltage control unit 13. Note that a description of the same contents as those in Embodiment 1 is omitted.

  The target circuit 14 is a circuit to be subjected to a check test. The target circuit 14 may correspond to the memory unit 12 of the first embodiment. The control unit 15 performs a check test by comparing input data and output data for the target circuit 14. The control unit 15 may correspond to the control IC unit 11 of the first embodiment. The voltage control unit 13 changes the drive voltage supplied to the target circuit 14 when the check test result is abnormal. Then, after the voltage control unit 13 changes the drive voltage, the control unit 15 performs a check test on the target circuit 14. This way, you can test more appropriately.

Other embodiments.
As another embodiment of the invention, the target circuit of the self-check test is described as a memory such as DRAM, DDR, etc., but it is not limited to memories, and is replaced with various electronic devices such as CPU, FPGA, ASIC LSI, etc. Is also feasible.

  Although the present invention has been described with reference to the exemplary embodiments, the present invention is not limited to the above. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

DESCRIPTION OF SYMBOLS 10 Electronic device 11 Control IC part 12 Memory part 13 Voltage control part 14 Target circuit 15 Control part 101 Self-check instruction | indication signal
102 Check signal 103 Drive voltage 104 Monitoring voltage 105 Control signal 106 Response signal

Claims (8)

The target circuit to be checked, and
A control unit that performs a check test by comparing input data and output data for the target circuit;
A voltage control unit that changes a drive voltage supplied to the target circuit when the check test result is abnormal, and
The controller is
When the drive voltage is monitored and the check test result is abnormal, it is determined whether or not the drive voltage is within a normal voltage range, and when it is determined that the drive voltage is within a normal voltage range, When an adjustment instruction for boosting control to the maximum drivable voltage that is the highest drive voltage that can be supplied by the voltage control unit is transmitted to the voltage control unit, and it is determined that the drive voltage is outside the normal voltage range, the normal voltage range An adjustment instruction for voltage control is transmitted to the voltage control unit,
An electronic device that performs the check test of the target circuit after the voltage control unit changes the drive voltage in accordance with the adjustment instruction .   The target circuit to be checked, and
  A control unit that performs a check test by comparing input data and output data for the target circuit;
  A voltage control unit that changes a drive voltage supplied to the target circuit when the check test result is abnormal, and
  After the voltage control unit changes the drive voltage, the control unit performs the check test of the target circuit,
  The voltage control unit gradually changes the drive voltage to obtain a boundary between the drive voltage at which the check test result is abnormal and the drive voltage at which the test result is normal,
  When the check test result is normal and the check test result for the drive voltage closest to the boundary is normal, the drive voltage closest to the boundary is set as the operating voltage, and the drive closest to the boundary is driven. An electronic device that determines an abnormality when the result of the check test for voltage is not normal. The check test if the result is abnormal, the check test results until the normal electronic apparatus according to the voltage control unit according to claim 1 or 2 gradually changing the driving voltage. The electronic device according to any one of claims 1 to 3 , wherein when the number of check tests exceeds a threshold, the electronic device is determined to be in error. A check test is performed by comparing the input data and output data for the target circuit.
If the check test result is abnormal, determine whether the drive voltage supplied to the target circuit is within a normal voltage range;
When determining that the drive voltage is within the normal voltage range, the drive voltage is changed to the maximum driveable voltage that is the highest drive voltage that can be supplied to the target circuit, and the drive voltage is outside the normal voltage range. When determining that, the drive voltage is changed within the normal voltage range ,
An electronic device test method for performing the check test on the target circuit after changing the drive voltage.   A check test is performed by comparing the input data and output data for the target circuit.
  When the check test result is abnormal, the drive voltage supplied to the target circuit is changed,
  After changing the drive voltage, perform the check test of the target circuit,
  By determining the drive voltage in stages, a boundary between an abnormal drive voltage at which the check test result becomes abnormal and a normal drive voltage at which the test result is normal is obtained,
  When the check test result for the normal drive voltage closest to the boundary is normal, the normal drive voltage closest to the boundary is an operating voltage, and the check test result for the normal drive voltage closest to the boundary is not normal, A method for testing electronic equipment that is determined to be abnormal. The test method according to claim 5 or 6 , wherein when the check test result is abnormal, the drive voltage is changed until the check test result becomes normal. The check if the number of tests exceeds a threshold value, the test method according to any one of the electronic device the error determining claims 5-7.

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