JP3442921B2 - Data 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 data inspection device which reads input data that has been transferred twice and uses this input data as output data for a CPU only when the same data is received twice in succession. Regarding

[0002]

2. Description of the Related Art When performing network communication, it is checked whether or not the transferred input data is data containing noise. As a checking method, a parity check method and a data collating method are used. Etc. have been adopted.

Among them, the above-mentioned data collating method is a method in which the input data transferred is read twice and the input data is adopted only when the same data is received twice consecutively. And a data inspection device having a configuration as shown in FIG.

Here, the data inspecting device as shown in FIG. 5 is a device for collating the input data consisting of 1 word and n bits and m words, and the contents of each word of the previous input data. The word data holding circuit 211 that holds (hereinafter simply referred to as word data) and the output data to be output to the CPU are configured, and
Output word data holding circuit 21 for holding word data
2, a data holding unit 21, a comparator 22, and a comparator MPX for selectively outputting data to be output to the comparator 22.
(Multiplexer) 23, output MPX (multiplexer) 24 for selectively outputting to the CPU, the above circuits and the like (21-
24) for controlling 24).

This data inspection device compares whether or not each word data forming the input data and the word data of the previous input data held in the corresponding word data holding circuit 211 match. The word data holding circuit 21
The word data held in 1 is output to the output word data holding circuit 212 to update the content, and the updated word data is output via the output MPX 24.
If they do not match, the output word data holding circuit 21
The contents of No. 2 are not updated, and the previous word data that is not updated is output via the output MPX 24.

Next, the data collation of this data inspection apparatus will be further described with reference to the timing chart shown in FIG.

This data inspection device, when the input data is the same as the previous input data (,, reference),
The previous word data held in the word data holding circuit 211 is used to update the word data held in the output word data holding circuit 212, and the updated word data is output as output data, while the input data is If it is not the same as the previous input data (,,,
In the reference), the output word data holding circuit 212 is not updated, and the previous word data that is not updated is output to the CPU as output data.

Further, in the conventional data inspection apparatus as shown in FIG. 7, in order to reduce the circuit scale of the hardware, the data selection means 35 (software) is used to read twice. An output word data holding circuit 312 that holds each word data forming data,
An output MPX 34 that selectively outputs word data, an internal memory 36 that stores previous input data, and an output MPX
The word data selectively output from X34 is compared with the word data in the internal memory 36 corresponding to the word data, and if all the word data match, this is set as output data, and this time data is stored in the internal memory 36, On the other hand, when they do not match, the output data of the previous time is continuously output, and the data selection means for holding the current data in the internal memory 36 is provided.

The processing operation of the data inspecting apparatus of FIG. 7 will be described with reference to the flow chart of FIG. 8. The data selecting means 35 first adds 1 to a counter (not shown) (i = i + 1) (step). 810) The output MPX is made to select the word data to be collated from the word data input from the word data holding circuit 312, and this data is read (step 820), and the previous input data is read from the internal memory 36. The word data corresponding to this is read (step 830).

Next, the data collating means 35 uses the output MP.
The word data selected and output from X34 is compared with the corresponding word data of the previous input data (step 840). As a result, when both data do not match (step 840; non-match), this data is Discard (step 850). On the other hand, if both data match (step 840; match), this data is output to the CPU as output data (step 860).

In this way, the data reference means 35 completes the processing of discarding the data of step 850 or the processing of using the data of step 860 as described above, and at the same time, the input data of this time is stored in the internal memory 36. It is stored (step 870), then it is judged whether or not all the word data are compared (step 880). As a result, if all the word data are not compared (step; No), step 810, the same processing as described above is performed, and when it is determined that all word data have been compared (step 880; Ye
s), the output process of the input data this time is completed.

[0012]

However, these data inspection devices described above have the following problems.

That is, in the data inspection apparatus shown in FIG. 5 described above, the software only needs to read the data, but the hardware holds the word data holding circuit 211 for holding the previous input data and the output data. Since it has the output word data holding circuit 212 for storing the word data, the number of the previous word data holding circuits 211 for holding the n-bit word data is required to be m, which causes a problem that the scale of the hardware configuration becomes large.

On the other hand, in the data inspection apparatus shown in FIG.
Compared to the data inspection apparatus shown in FIG. 5, the word data holding circuit is not required at the previous time, so the scale of the hardware configuration can be small, but the load of software processing is increased and the internal memory is required. There was a point.

In view of the above problems, it is an object of the present invention to provide a data inspecting apparatus that reduces the scale of the hardware configuration and reduces the load of software processing when performing data collation. .

[0016]

In order to achieve the above-mentioned object, the invention according to claim 1 has a plurality of transferred work.
Reads input data composed of Dodeta, when reading the same data twice in succession, a data checking apparatus for outputting to the CPU an input data as a correct output data, each one by one dose the input data Word data
It is sequentially and holds corresponding to the input data of the one time corresponding to each word data each time the input data is transferred
When input data holding means for sequentially updating and holding the input data and new input data are transferred, the previous input data held in the input data holding means is selectively output as the previous data for each word data. Each word corresponding to whether or not the control unit to be operated and the previous data output from the control unit and the newly input input data of this time correspond to each other.
Determining means for determining for each data, a determination result storing means for storing a 1-bit flag in the ON or OFF indicating a match or mismatch for each word data as a determination result of the determination means, in the determination result storage unit type 1 bit flag for each word data stored, its
All 1-bit flags of each word data of
That in the case of effect select employs an input data held in said input data holding means as a correct output data, CP
Output to U and
If some of the 1-bit flags do not match, the CPU
And a data selecting unit that does not output the data.

According to a second aspect of the present invention, in the first aspect of the present invention, the judgment result storage means stores the data.
The bit flag is held by the input data holding means.
Is stored with a predetermined 1-bit flag of the input data
Characterized in that that.

[0018]

According to the present invention, it is determined whether the current input data and the previous input data match, and if the current input data and the previous input data match, the current input data Is output as output data to the CPU.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a data inspection apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the data inspection apparatus of the first embodiment.

The data inspecting device of this embodiment is a device for performing data collation for input data consisting of, for example, 1 word n bits and m words, and this inspecting device corresponds to each word of this input data. Have # 1
#M data holding unit 1, comparator 2, comparator MPX (multiplexer) 3 for selectively outputting data to be output to the comparator 2, flags input from # 1 to #m data holding unit 1, and MPX for output that selectively outputs output data
4, a data selection unit 5, and a control unit 6 that controls the circuits and the like (1 to 4).

The data holding units 1 of # 1 to #m hold an output word data holding circuit 11 that holds the word data that constitutes the input data this time, and a status flag holding that holds a status flag bit consisting of 1 bit described later. And a circuit 12.

Under the instruction of the control unit 6, the comparator 2 determines whether the word data of the previous input data held in the output word data holding circuit 11 and the word data of the current input data match. It is configured to judge whether or not.

When the word data of the previous input data and the word data of the current input data match, the comparator 2 applies the corresponding state flag holding circuit 1
On the other hand, the flag flag of 2 is set to ON, and when the two do not match, the state flag holding circuit 12 is set to set the flag bit of OFF.

The data selecting means 5 receives the status flags from the status flag holding circuit 12 of # 1 to #m selectively output via the output MPX 4 and the output data from the output word holding circuit 11. Therefore, only when all the status flags # 1 to #m are ON, the output data composed of the output word data input from the output word data holding circuit 11 from # 1 to #m is output to the CPU (not shown). ) Is output to.

Next, the operation of the data inspection apparatus of this embodiment will be described.

When the input data is transferred, the control unit 6
Is the previous input data # 1 held in the # 1 output word data holding circuit 11 with respect to the comparator MPX3.
The word data of 1 is selectively output to the comparator 2.

The comparator 2 receives the # 1 word data of the input data and the # 1 selectively input from the comparator MPX3.
It is determined whether or not the word data of No. 1 and the word data of No. 1 match, and as a result, if it is judged that they match each other, an ON flag bit is set in the status flag holding circuit 12 of # 1, while if they do not match, # OFF to the status flag holding circuit 12 of 1
Set the flag bit of.

After that, the control section 6 updates the contents of the # 1 output word data holding circuit 11 with the # 1 word data of the input data.

Here, the # 1 output word data holding circuit 11 stores the # 1 word data of the input data, and at the same time, stores the # 1 word data of the stored input data as a candidate for the output data. Is output to the output MPX 4, and the # 1 state flag holding circuit 12 also outputs the stored state flag to the output MPX at the same time that the state flag is newly stored.

In this way, the input data # 2 to #
Similar processing is performed on word data for m.

When the last word data of the input data, that is, the word data of #m, the output word data holding circuit 11 and the status flag holding circuit 12 of #m are respectively stored with the output word data and the status flag, The control unit 6 transfers control to the data selection means 5.

FIG. 2 is a flow chart showing the processing performed by the data selecting means.

The data selecting means 5 adds 1 to the counter (i = i + 1) (step 210), reads the status flag stored in the status flag holding circuit 12 of #i (step 220), and reads the status. Check the flag (step 230).

As a result, when the status flag is OFF (step 230; OF), the data selecting means 5
F), the process is terminated, and when the status flag is ON (step 230; ON), the output word data of #i stored in the output word data holding circuit 11 of #i is read (step S230). 240), this data is listed as a candidate for using the output data (step 250).

Next, the data selecting means 5 judges whether i is m (step 260). If i is not m (i <m) (step 260; No), the process is stepped. Return to step 210 and perform the same processing as above, while i
= M (step 260; Yes), output M
The output word data held in the #m output word data holding circuit 11 is sequentially output to the CPU from the output word data held in the # 1 output word data holding circuit 11 via the PX4. That is, the output data is output to the CPU.

Next, the data collation of this data inspection device will be further described with reference to the timing chart shown in FIG.

In this data inspecting apparatus, when the input data is the same as the previous input data (and reference), all the status flags # 1 to #m are turned on, and at this time, # 1 Each word data of the current input data held in the output word data holding circuit 11 of #m to #m is sequentially output to be output as output data to the CPU.

On the other hand, in this data inspection apparatus, when the input data is not the same as the previous input data (,, and reference), at least one of the status flags # 1 to #m is turned off. At this time, the word data held in the # 1 to #m output word data holding circuits 11 is not output to the CPU. Therefore, the output data is not output to the CPU.

According to this embodiment, the data selection means 5
Since the output word data is taken out from the output word data holding circuit 12 when all the status flags are ON in n, compared with the one shown in FIG. 5, n bits × m 1 bit recording instead of this storage circuit. Since only m circuits are required, the scale of hardware can be reduced.

Further, since the number of processing steps can be reduced as compared with that shown in FIG. 7, the software processing can be reduced.

In another embodiment, the hardware has a configuration similar to that of the embodiment shown in FIG. 1, but a predetermined bit (eg M
SB (Most Significant Bit) is used as a flag bit, and when this bit is OFF, this word data is discarded. This process is performed according to the flowchart shown in FIG.

Next, the processing of the data selecting means which constitutes the data inspection apparatus of this embodiment will be described with reference to FIG.

The data selecting means 5 first increments a counter (not shown) by 1 (i = i + 1) (step 41).
0), the output word data is read from the output word data holding circuit 12 of #i with respect to the output MPX (step 420).

Next, the data selection means 5 determines based on the flag bit of the output word data (step 430) that the flag bit indicates OFF (step 430; O).
FF), discard this output word data (step 45).
0) If the flag bit indicates ON while the processing is completed (step 430; ON), this word data is set as a candidate for word data forming the output data (step 440).

Next, the data selection means judges whether the word data currently being processed is the last data (step 460), and when it judges that it is the last data (step 460). Yes), MPX for output
The output word data held in the #m output word data holding circuit 11 is sequentially output to the CPU from the output word data held in the # 1 output word data holding circuit 11 via 4 (step 470), That is, CP
When the output data is output to U, and when it is determined that it is not the final data (step 460; No), the process is returned to step 410 and the same process as described above is performed.

[0048]

As described above, according to the present invention, it is determined whether the current input data and the previous input data match, and if the current input data and the previous input data match. Since the current input data is output as the output data to the CPU, the hardware does not need a word data holding circuit for holding the previous input data, and the scale of the hardware configuration can be reduced.

Further, the internal memory for storing the previous input data is not required and the load of software processing can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a data inspection device according to the present invention.

FIG. 2 is a flowchart showing the processing of a data selection means in FIG.

FIG. 3 is a timing chart showing the processing operation of the data inspection device of this embodiment.

FIG. 4 is a flowchart showing a process of a data selection unit according to another embodiment.

FIG. 5 is a block diagram showing the configuration of a conventional data inspection device.

6 is a timing chart showing the processing operation of the conventional data inspection device shown in FIG.

FIG. 7 is a block diagram showing a configuration of a conventional data inspection device.

8 is a flowchart showing the processing of the conventional data inspection device shown in FIG.

[Explanation of symbols]

1 Data storage 2 comparator 3 MPX for comparator MPX for 4 outputs 5 Data selection means 6 control unit 11 Status flag holding circuit 12 Output word data holding circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-75302 (JP, A) JP-A-6-14012 (JP, A) JP-A-59-200365 (JP, A) JP-A-2- 18613 (JP, A) JP 5-189990 (JP, A) JP 4-360317 (JP, A) JP 6-103096 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G06F 11/00 G06F 11/08

Claims (2)

(57) [Claims] 1. A plurality of word data that have been transferred
When the same data is read twice consecutively, the data inspection device outputs the input data as correct output data to the CPU, and the input data is read once for each word data. Correspond to
Sequentially holding Te, the input data holding means for inputting data held sequentially updated to be made to correspond to the input data of the one time every time that is transferred to the word data and newly input data is transferred , A control unit which selectively outputs the previous input data held in the input data holding means as the previous data for each word data, the previous data output from the control unit and the newly input current input Whether each data corresponds or not
The judgment result storing means, the judgment result storing means for storing a 1-bit flag of ON or OFF indicating that there is a match or no match for each word data as a judgment result of the judgment means, and the judgment result storing means. Stored word data
Input the 1-bit flag with and, for each word data
When all the 1-bit flags are in agreement, the input data held in the input data holding means is selected and adopted as correct output data and is output to the CPU, and the 1-bit flag for each word data is set. part
And a data selection unit that does not output to the CPU if the two do not match . 2. The 1-bit flag stored in the determination result storage means is stored as a predetermined 1-bit flag of the input data held in the input data holding means. 1. The data inspection device according to 1.