JP2601192B2 - Reading inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading and inspecting apparatus for inspecting a reading apparatus for reading data from a peripheral device, and more particularly to a reading and inspecting apparatus for inspecting whether data reading timing is normal.

[0002]

2. Description of the Related Art A CPU (Central Processing Unit) and a personal computer (these are collectively referred to as a reading device).
Can be connected to various peripheral devices. When the reading device reads data from the peripheral device, first, a reading timing signal for reading data is output. After the peripheral device receives this read timing signal,
Start data output operation. Since it takes some time for the peripheral device to output data after receiving the read timing signal, it is necessary for the reading device to wait until data is output before reading. The time required from receiving the read timing signal to outputting the data differs depending on the peripheral device. Therefore, if the waiting period is fixed, this period must be set according to the peripheral device that takes the longest time to output data. In this case, even if another peripheral device outputs data earlier than this period, the data cannot be read efficiently because the data is read after the set period has elapsed.

Therefore, the period during which the reading device waits uniformly is set relatively short, and the reading is temporarily prevented only when the peripheral device cannot output data within this period so that the period is extended. ing. That is, a peripheral device that takes longer to output data than the set period outputs a read inhibition signal that temporarily inhibits data reading. When a reading inhibition signal is input from a peripheral device, the reading device waits for the termination of this signal before reading the data value.

When such a reading device is shipped as a product, it is necessary to check whether data reading is temporarily blocked in response to a reading blocking signal.
As one of inspection methods conventionally performed, there is a method of observing a waveform of a read timing signal or a read prevention signal. The reading timing signal output by the reading device is continuously output from the start of the output until immediately before the data is read. That is, if the reading is temporarily blocked, the period during which the reading timing signal is output becomes longer. Therefore, inspection is performed by observing the waveforms of these signals with a synchroscope to determine whether the period during which the read timing signal is output in response to the read inhibition signal is long. However, when the operator performing the inspection generates the read inhibition signal in a pseudo manner, it is difficult to generate the read inhibition signal in synchronization with the output timing of the read timing signal. For this reason, in many cases, the waveform when the data reading is temporarily blocked can be recorded on the synchroscope only after the read blocking signal is generated many times, and the inspection work takes time and labor.

Therefore, there is an inspection method using an inspection board that outputs a read inhibition signal at a timing corresponding to a read timing signal input from the reader. The value of the data output from the inspection board is predetermined. In the inspection, first, the reading device reads data from the inspection board. Next, it is determined whether or not the read value matches the value of predetermined data output from the test board. If they match, it is determined that data reading has been temporarily blocked in accordance with the read blocking signal output from the test board, and if they do not match, it is determined that temporary blocking has not been performed. .

[0006]

When an inspection is performed using an inspection board, the pass / fail of the inspection is determined based on whether or not the data read by the reading device matches a predetermined value. However, the inspection board stops outputting the read inhibition signal after outputting the data. In some cases, data is output long before the output of the read inhibition signal is stopped. Therefore,
Even when data reading is not temporarily blocked in response to the read blocking signal, predetermined data may be read. Even if data is output long before the output of the read inhibition signal is stopped, if the read data does not match the predetermined value, the reading is not temporarily inhibited. Can be confirmed. But if they match,
It is not possible to determine whether the data match was due to the early output of data from the test board or the data was temporarily blocked from being read. Therefore, it is necessary to confirm the relationship between the read inhibition signal and the timing at which the data is output using a synchroscope, and the inspection operation is inefficient.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a reading inspection apparatus capable of easily confirming whether data reading is temporarily stopped in response to a reading prevention signal.

[0008]

According to the first aspect of the present invention, there is provided: (a) a base for operating timing of an apparatus for reading data.
System clock to input the standard system clock
Lock input means; and (b) a device for reading the data.
Timing that indicates when the device reads data
Reading timing signal input means for inputting a signal;
Input system clock and read timing signal before
The system clock is counted from the read timing described.
When this is counted by a predetermined number,
Invert the binary data signal as output from the initial state
And (d) the aforementioned data signal of this counter.
Signal and read timing signal and the data described above
A test signal indicating whether or not the
The data signal is in the initial state described above, and
Before the scanning signal indicates the read timing.
Data is read only when no inspection is performed
Output a read block signal to block the read operation of the device
Reading prevention signal output means for reading data (e)
Only when the reading inspection of the device is performed,
Counter operation control means for enabling the
(F) After the period during which the read inhibit signal is output,
Device that reads data from the signal state of the data signal
Data read is temporarily blocked by the read block signal
The reading / inspection apparatus is provided with a determining means for determining whether or not the reading has been performed.

That is, according to the first aspect of the present invention, the state of the signal to be read is changed between the period during which the read inhibition signal is output and the period thereafter. Thus, it is possible to determine whether the read signal is before or after the state is changed, and it is possible to determine whether the reading of the data is temporarily blocked by the read blocking signal.

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

FIG. 1 shows a schematic configuration of a reading inspection apparatus according to an embodiment of the present invention. Reading inspection device 1
1 is connected to the device under test 12 to be tested. Here, a personal computer is targeted for inspection, and it is inspected whether or not the reading is temporarily blocked by the read blocking signal. The reading / inspection apparatus 11 includes an inspection signal generating unit 13 that outputs data to be read by the apparatus to be inspected 12 and an inspection result determination that determines whether data has been read by the apparatus to be inspected 12 to determine whether or not the inspection is successful and displays the result. And a unit 14. Inspection device 1
2 to the inspection signal generator 13, the read timing signal 15
Is entered. A read inhibition signal 16 and a data signal 17 to be read are input from the test signal generator 13 to the device under test 12. In addition, the device under inspection 12
The system clock 18 serving as a reference for the operation timing of the test signal is input to the inspection signal generator 13.

When the read timing signal 15 is input, the test signal generator 13 receives a test signal 19 for switching whether or not to output the read inhibition signal 16. Read timing signal 15, Read inhibit signal 16
And the test signal 19 have negative logic.
That is, it is “on” when “0” (low level) and “off” when it is “1” (high level). The read instruction signal 21 for instructing the inspection target device 12 to read data from the inspection result determination unit 14 is input. Further, a read data detection signal 22 for inputting data read by the inspection target device 12 is input to the inspection result determination unit 14.

FIG. 2 functionally shows the circuit configuration of the inspection result determination section shown in FIG. Inspection result judgment unit 1
Reference numeral 3 includes a detection unit 23 that detects data read by the device under test 12, a determination unit 24 that determines whether data reading is temporarily blocked, and a display 25 that displays the determination result. ing. Here, a CRT is used as a display. In addition, a liquid crystal display panel or the like can be used.

FIG. 3 shows a circuit configuration of the inspection result determination unit. The inspection result determination unit 14 includes a CPU 31 which is a center of various controls. The CPU 31 is connected to various circuit devices through a bus 32 such as a data bus.
The ROM 33 is a read-only memory that stores a program for starting the test result determination unit 14 and fixed data such as a value to be compared with a value of data read by the device under test 12. A RAM (random access memory) 34 temporarily stores a test program and various data. The magnetic disk control unit 35 controls input and output to and from the magnetic disk device 36. The magnetic disk device 36 stores various programs in addition to the inspection program. The display controller 37 causes the display 38 to display data such as inspection results. The input circuit 39 is connected to the keyboard 41 so that a person who performs the inspection can input various commands and data such as an instruction to start the inspection. The interface unit 42 inputs and outputs the read instruction signal 21 and the read data detection signal 22 with the device under test 12.

FIG. 4 shows a circuit configuration of the inspection signal generator. The system clock 18 and the read timing signal 15 are input to a first OR (logical sum) circuit 51. The output of the first OR circuit 51 is connected to the clock input terminal of the counter 52. First OR circuit 5
Since the logical sum of the read timing signal 15 and the system clock 18 is obtained by 1, the counter 52 starts counting up from the time when the read timing signal is turned “ON”. The counter 52 changes its output from “0” to “1” when counting up to a predetermined number set in advance. Here, it is set to change to “1” when 32 clocks are counted.

The output of the counter 52 is input to the device under test 12 as the data signal 17 to be read. The data signal 17 changes from “0” to “1” when the system clock 18 is counted 32 clocks after the input of the read timing signal 15. The read timing signal 15 and the output of the counter 52 are supplied to a second OR circuit 53.
Has been entered. The output of the second OR circuit 53 and the test signal 19 are input to the third OR circuit 54. Therefore, the output of the third OR circuit 53 becomes "0" only while all of the test signal 19, the read timing signal 15, and the output of the counter 52 are "0". The output of the third OR circuit 54 is used as the read inhibition signal 16 as the device under test 12.
Has been entered. The test signal 19 is input to the enable terminal of the counter 52, and is counted up only when the test signal 19 is "ON".

The read timing signal 15 output from the device under test 12 is "0" from the time it is output to the time data is read. That is,
While data reading is blocked, the read timing signal 15 is "0". Then, when the reading is not blocked, the counter 52 counts a time longer than the time when the read timing signal 15 is "0". As a result, during the period from when the read timing signal 15 becomes “0” to when the output of the counter 52 changes to “1”, the read prevention signal 16 is turned on.

A case where the reading timing of a device to be inspected is inspected by using the inspection device having the above configuration will be described. At the start of the test, first, the test signal 19 is turned on. As a result, the inspection signal generator 13 generates the read inhibition signal 16 when the read timing signal 15 is input. Next, the inspection program is transferred from the magnetic disk device 36 to the RAM based on the instruction of the operator.
34.

FIG. 5 shows the flow of processing performed by the inspection result determination unit. The CPU 31 shown in FIG. 3 is waiting for an instruction to start an inspection from the keyboard 41 (step S101). An instruction to start the test is sent from the keyboard 41 through the input circuit 39 and the bus 32 to the CP.
It is transmitted to U31. The instruction to start the test is issued by the keyboard 41
Input from the CPU 3 (step S101: Y), the CPU 3
1 outputs a reading instruction signal. (Step S102).
The read instruction signal is sent to the interface unit 4 through the bus 32.
2 to the device under test 12. The device under test 12 reads data from the test signal generator 13 when the read instruction signal is input. After outputting the reading instruction signal, the CPU 31 waits for one second to elapse (step S10).
3). This is because the device to be inspected 1
2 waits until the data has been read. That is, it waits for a time longer than the sum of the time from when the device under test 12 receives the read instruction signal to the start of the reading operation and the time required to read data when reading is blocked. Thereafter, the CPU 31 captures the value of the data read by the device under test 12 through the interface unit 42 (step S104). The value taken is RAM
34 is temporarily stored.

The inspection signal generator 13 outputs "0" as the data signal 17 while the read inhibition signal 16 is "ON", and outputs "1" as the data signal 17 when the read inhibition signal 16 is "OFF". Is output. Therefore, the CPU 31
It is determined whether or not the value fetched from the device under test 12 stored in M34 is “1” (step S10).
5). If the read data is “1” (step S105: Y), the CPU 31 outputs a signal to the display control unit 37 so that the character “inspection passed” is displayed. The display control unit 37 controls the display 38 based on this signal, and the characters "inspection passed" are displayed (step S1).
06). If the read data is not “1” (step S105: N), the CPU 31 outputs a signal to the display control unit 37 so that the character “inspection failed” is displayed. The display 38 is controlled by the display control unit 37 to display the characters “inspection failed”. Thereafter, the CPU 31 ends the processing (end).

In the case of the present embodiment, the judgment as to whether or not the test has passed is 1
Degrees are read based on the results. In order to improve the reliability of the inspection, the device to be inspected may repeatedly read the data a plurality of times. Inspection is displayed only when all the values read over a plurality of times are "1", and inspection failure is displayed when a value other than "1" is read even once. Inspection reliability is improved.

FIG. 6 shows the waveform of each signal when the device under test reads data when the test signal is "OFF". The system clock 18 ((a) in the figure) is a rectangular wave of 8 MHz. In this case, since the test signal 19 is "OFF", the read inhibition signal 16 (FIG. 9 (c)) is always "OFF" and the reading is not inhibited. When read inhibit signal 16 is not input, the inspection device 12 is read timing signal 15 (Fig. (B)) four clock between "on" and the time T ₁₁ "off"
To Device under test 12 the value of the data signal 17 at time T ₁₂ after one clock (Fig. (D)) is taken into the inside. When the test signal 19 is in the "OFF" state, the counter 52 does not perform the counting operation, so that the output data signal 17 remains "0". Thus, when the test signal 19 is "OFF", the device under test 12 reads the value "0" of the data signal 17 at time T ₁₂ 5 after clock from the output of the timing signal 15 read.

FIG. 7 shows a case where the test signal is "ON".
Reading of the device under test is temporarily blocked according to the blocking signal
FIG. 6 shows the waveforms of the respective signals in the case where the processing is performed. Tess
When the read signal 19 is “ON”, the read timing signal
No. 15 (FIG. 9B) is turned on at the same time
The stop signal 16 ((c) in the figure) is turned on (at time
T ₁₃). Time T 32 clocks later₁₄Read inhibit signal
16 is "off". In this case, the read inhibition signal 16
The reading is temporarily blocked in response to the
The device 12 is reset for two clocks after the read block signal 16 is turned off.
Time T after lock_FifteenTo the read timing signal 15
And a time T one clock after that ₁₆Smell
Read the value of the data signal 17 ((d) in FIG.
You. Therefore, if reading is temporarily blocked
Is read as "1".

When the test signal is turned "OFF", the personal computer to be inspected reads data after 5 clocks. Here, the period during which the read inhibition signal is output is 32 clocks, which is set to a period sufficiently longer than 5 clocks. This is for clearly discriminating whether or not reading is temporarily blocked in accordance with the reading blocking signal even when the reading timing of the personal computer is slightly shifted for some reason. Causes of the timing shift include a shift in the timing at which the personal computer detects the read inhibition signal, a shift in the timing of fetching data, a transmission delay of each signal, and an irregular clock waveform. In consideration of the above, if the read inhibition signal is output for a period twice or more of the normal read operation, the reliability of the inspection can be sufficiently ensured.

FIG. 8 shows the waveform of each signal when data reading is not temporarily blocked in response to the reading blocking signal when the test signal is "ON". Reading timing signal 15 (Fig. (B)) becomes "on" simultaneously read inhibit signal 16 (FIG. (C)) also becomes "on" (time T _17). However, the timing signal 15 read at time T ₁₈ after the four clocks if temporary blocking of the reading is not performed will return to "off". As a result, the read inhibition signal 16 is also turned "off".

When the read timing signal 15 becomes "1", the counter 52 stops counting and the data signal 1
7 ((d) in the figure) is kept at "0". Therefore, the device under test 12 reads “0”, which is the value of the data signal 17 at time T _19, one clock after the read timing signal 15 is turned “off”.

During the period in which the read inhibition signal 16 is being output, the value of the data signal 17 is "0". On the other hand, it is "1" in the subsequent period. Therefore, if the data is read during the period during which the read inhibition signal is output without temporarily preventing the reading, the value becomes “0”.
become. Conversely, if data is read after reading is blocked while the reading blocking signal 16 is being output, the value becomes "1". Since the value of the data to be read changes at the same time as the end of the output of the read inhibition signal, it is possible to determine whether or not the read has been temporarily inhibited based on the read data. it can.

When the test signal 19 is turned off, the data signal 17 is always "0". Therefore, at this time, if the value read by the device under test 12 is “1”, it can be understood that some abnormality has occurred in the connection with the device under test 12 or the read inspection device 11. As a result, even if the test signal 19 is turned on and the test is performed, and the device under test 12 reads "1", it can be easily grasped that the test result cannot be trusted. As described above, the inspection can be performed both when the read inhibition signal 16 is input and when the read inhibition signal 16 is not input only by changing the test signal 19 “ON” and “OFF”. Can be.

In the embodiment described above, the system clock of the device to be inspected is used as the clock signal of the counter of the reading and inspecting device. However, the clock is not limited to this, and a separate clock may be used. It is not necessary to measure the period during which the read inhibition signal is output by the counter,
For example, the time may be measured using the charging time of the capacitor.

In the case of inspecting the reading timing of the personal computer, the inspection result can be determined by using the function of the personal computer. In this case, the inspection target is a circuit portion that controls the timing of reading data in the personal computer. Other parts can function as the inspection result determination unit in the embodiment. Although the flow of the process may be the same as that shown in FIG. 4, the personal computer proceeds to the next step after reading the data from the test signal generator, so that the process of waiting for one second (step S102) can be omitted.

The inspection result determination section may have the following configuration. Read timing signal changes from "0" to "1"
Is held by the latch circuit. The light emitting diode is turned on according to the value of the held data signal 17. For example, the data signal 17
Is set to "1", it is possible to judge that reading is temporarily blocked when the light emitting diode is turned on. That is, even if it is not necessary to determine the value of the actually read data, if the time at which the data is read is determined by the read timing signal, it is determined whether or not the temporary interruption was performed based on the value of the data signal 17 at that time. Can be determined.

[0039]

As described above, according to the first aspect of the present invention, a system clock is input and the system clock is input to a counter.
So that the output of the read inhibit signal is
Is changed by the frequency of the system clock.
In other words, reading the length according to the operation speed of the reading device
A blocking signal can be obtained. Therefore, the system
Inspecting several readers with different lock frequencies
However, these inspections can be performed efficiently. Ma
Further, the read inhibition signal output means outputs the data signal and the read time.
Signal and test signal to input these logics.
Output the read inhibit signal, and output the read inhibit signal.
The signal state of the data signal after the period
Data reading is temporarily blocked.
Not only can you determine if it has been stopped,
Only by changing the signal state of the
Perform inspections both when input and when not input
And a highly reliable inspection can be easily performed.

[0040]

[0041]

[0042]

[0043]

[0044]

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration in a case where an inspection is performed by connecting a reading inspection apparatus according to an embodiment of the present invention to a device to be inspected.

FIG. 2 is a block diagram functionally showing a circuit configuration of an inspection result determination unit shown in FIG.

FIG. 3 is a block diagram showing a circuit configuration of an inspection result determination unit shown in FIG. 1 as a component arrangement.

FIG. 4 is a circuit diagram illustrating a schematic circuit configuration of a test signal generation unit illustrated in FIG. 1;

FIG. 5 is a flowchart illustrating a flow of a process performed by an inspection result determination unit in the embodiment.

FIG. 6 shows that a test signal is “off” in a test signal generator.
FIG. 9 is a waveform diagram showing waveforms of signals when data is read at the time of FIG.

FIG. 7 shows that the test signal is “ON” in the test signal generator
FIG. 9 is a waveform diagram showing waveforms of signals when data reading is temporarily blocked in response to a read blocking signal.

FIG. 8 shows that a test signal is “ON” in a test signal generation unit.
FIG. 7 is a waveform diagram showing waveforms of signals when data reading is not temporarily blocked in response to a read blocking signal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Read inspection apparatus 12 Device under test 13 Inspection signal generation part 14 Inspection result determination part 15 Read timing signal 16 Read inhibition signal 17 Data signal 18 System clock 19 Test signal 21 Read instruction signal 22 Read data detection signal 23 Detection part 24 Determination part 25, 38 display 31 CPU 33 ROM 34 RAM 36 magnetic disk device 39 input circuit 52 counter

Claims (1)

(57) [Claims] 1. An operation timing of an apparatus for reading data
System that inputs the system clock
Clock input means, and a timing at which the device for reading the data reads the data.
Timing for inputting a read timing signal indicating
Signal input means for inputting the system clock and the read timing signal;
Counting the system clock from the read timing.
When this is counted by a predetermined number,
Invert the binary data signal as output from the initial state
Counter, and the data signal and the read timing signal of the counter.
And whether or not the device that reads the data
The test signal shown in FIG.
The read timing signal controls the read timing.
Before inspection and no inspection is performed.
The reading operation of the device that reads the data only when
Signal for outputting a read inhibition signal for reading
And a state in which the reading inspection of the device for reading the data is performed.
Counter that enables the counter only when
Operation control means, and after the elapse of the period during which the read inhibition signal is output,
Reading the data from the signal state of the data signal
The device stops reading data by the read inhibition signal.
A reading inspection apparatus comprising: a determination unit configured to determine whether or not the reading is temporarily stopped .