JPS62281611A - Signal edge detector - Google Patents

Abstract

PURPOSE:To omit the processing steps by using a circuit which collates the data written to a storage circuit with the dats read out of the storage circuit through the exclusive OR processing and then detecting the edge part of each signal. CONSTITUTION:The signals received from sensors S1-Sn are written to a storage circuit 12 in the form of the binary data and at the same time the data stored until a time point immediately before the latest data is written is read out of the circuit 12. Then the read-out data is collated with the written data through the exclusive OR processing. While an edge detecting circuit 14 detects the edge part of each signal. Therefore the collective edge detection can be applied to plural data regardless of the number of pieces of data and without preparing an edge detecting program for each sensor by performing write and read of data with a single storage circuit as well as the exclusive OR processing of both data. In such a way, the processing steps can be omitted.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention collectively detects rising or falling edges of a plurality of signals sent from a plurality of sensors. The present invention relates to a signal edge detection device.

[Prior Art] Control devices using black computers are contributing to the development of industry in all fields. Such microcomputer-applied technology is being actively introduced into passenger cars, where safety and comfort are important, for example, and the advanced processing capabilities of microcomputers are utilized to mechanically reduce vehicle slippage during braking, for example. A typical application is an anti-lock braking system that prevents accidents.

The control system l shown in FIG. 4 is the main part of an anti-lock braking system that detects the slip condition of the vehicle from the discrepancy between the vehicle speed and the rotational speed of the wheels, and operates the brake device 2 intermittently at high speed. However, there are multiple sensors such as a vehicle speed sensor that measures the speed of the vehicle, a rotation sensor that measures the number of rotations of the wheels, or a brake sensor that detects the on/off state of the brake device 2 from the pressure switch of the hydraulic system. s,,s3. ．． ．． ．． sn is connected to a control device 3 incorporating a microcomputer 3a.

This control system l includes a plurality of (n) sensors S, ~S
It is necessary to perform high-speed arithmetic processing on the signals sent from the sensor ``o'' and instantly supply the necessary control commands to the brake device 2. A signal edge detection device 4 that first determines the rise and fall of a signal that takes a value level.
When a change in the binary level is determined, it is assumed that there is a change in the state of the object to be detected, and it is determined whether or not the control command can be changed. In particular, in this example, each sensor S, -Sn
Since the rising edge of the human input signal is detected by software processing, a program for detecting the rising edge and falling edge of the signal is prepared for the edge detection circuit 4a provided for each sensor S, ~So. .

For example, in a rising edge detection program, as shown in FIG. 102
), it is determined whether the rising flag is set. If a negative result is obtained in this judgment, it can be seen that the human input signal, which had been at a low level until then, changed to a high level just before the judgment, so a rising flag is set in step (+03),
Along with the setting of this rising flag, the rising edge information of the signal is taken into the microcomputer 6a.

Note that if it is determined in step (101) that the human input signal is at a low level, the rising flag is reset in step (104), and the signal is returned to step (+02).
), the process moves to the next processing step.

[Problems to be Solved by the Invention] The signal edge detection device 4 applied to the conventional control system 1 described above has edge detection software prepared for each edge detection circuit 4+1L connected to each sensor S1 to So. , there are problems such as a large amount of software, which not only increases the storage capacity of the memory circuit that stores the edge detection program, but also increases manufacturing costs for both hardware and software.

[Means for Solving the Problems] The present invention solves the above problems, and includes a storage circuit that stores a plurality of signals sent from a plurality of sensors as binary data, respectively; A control circuit controls the storage circuit to write the latest data and read the data stored immediately before writing the latest data, and the control circuit controls the data written to the storage circuit and the data read out exclusively. The present invention is characterized in that it comprises an edge detection circuit that performs comparison by logical sum processing and detects edge portions of each of the signals.

[Operation] The present invention writes a plurality of signals sent from a plurality of sensors into a storage circuit as binary data, and also reads and writes data that was stored immediately before writing the latest data. The data to be read out and the data to be read out are compared by exclusive OR processing, and errors in each of the signals are detected. This will be explained with reference to the figures. FIG. 1 is a schematic circuit configuration diagram showing an embodiment of the signal edge detection device of the present invention, and FIG. 2 is a diagram illustrating an operation program for detecting a rising edge by the control circuit shown in FIG. It's a flowchart.

In FIG. 1, the signal edge detection device 11 includes a plurality of sensors S
, -Sn, each of which stores a plurality of signals as binary data, writes the latest data to this memory circuit 12, and stores the latest data until immediately before writing. a control circuit for controlling the reading of the data that has been stored] 3; and an edge detection circuit I4 for comparing the data written to the memory circuit 12 and the data to be read by exclusive OR processing and detecting edge portions of each of the signals. Furthermore, the edge detection circuit 14
The rising edge detection circuit 15 is configured to logically AND the output of the current data and the latest data.

Now, from a plurality of sensors S,,St,...,s,, for example, l0011. ,,The latest data called OI is stored in the memory circuit 1.
Suppose that it is supplied to 2. The data immediately before this data is 00101. ,．． Suppose it is 00. In this case, the output of the edge detection circuit I4 is 10110. ,．． 01
Therefore, the sensors s, , s3 . s...
, sn indicates output 1. Then, this edge detection output is further subjected to AND processing with the latest data in the rising edge detection circuit I5, and is +00
10. ,．． As indicated by 01, the sensors S,,S,,
It is detected that only the outputs of , , sn show a rising change.

By the way, the operation of the signal edge detection device 11, including the operation of writing and reading data to the memory circuit 12, and the operation of the edge detection circuit 14 and the rising edge detection circuit I5 may be processed by software. For example, a processing program for detecting a rising edge as shown in FIG. 2 is prepared in the control circuit 13. This processing program first writes the latest data into the storage circuit I2 in step (201), and at the same time reads out the data that had been stored in the storage circuit I2 up to that point. The data read out from the memory circuit 12 in this way is
In step (202), exclusive OR is performed with the latest data. Then, the exclusive OR output obtained in step (202) is further ANDed with the latest data in step (203), and the
In step 04), it is determined whether the AND output is at a high level or not. As a result, if the level is high, a rising edge is detected, and if not, the signal is subjected to subsequent signal processing.

Further, in the explanation here, the case where a rising edge of a signal is detected is explained as an example, but if the processing program shown in FIG. 3 is followed, a falling edge of a signal can be detected. This falling edge detection program takes exactly the same processing sequence as the rising edge detection program in step (201) and step (202), but the step (
In 2,05), the logical product with the exclusive OR output is the polarity inverted output of the latest human data, and as a result of the judgment process shown in the subsequent step (206), the logical product output is low level. They differ in that they sometimes detect falling edges.

In this way, the signal edge detection device II writes the plurality of signals sent from the plurality of sensors S1 to Sn into the storage circuit 12 as binary data, and also writes the signals sent from the plurality of sensors S1 to Sn into the memory circuit 12, and also The sensor s
Regardless of the number of data, it is possible to write and read data to and from a single memory circuit I2 and perform exclusive OR processing of both data, without having to prepare a separate program for edge detection for each of 1 to Sn. Multiple pieces of data can be subjected to edge detection processing at once, and a considerable number of processing steps can be simplified compared to conventional methods. - A signal edge detection device suitable for information processing devices such as microcomputers that perform A signal processing can be provided.

[Effects of the Invention] As explained above, the present invention writes a plurality of signals sent from a plurality of sensors into a storage circuit as binary data, and also writes a plurality of signals sent from a plurality of sensors into a memory circuit until immediately before writing the latest data. Since the configuration is such that the stored data is read out and the data to be written and the data to be read are compared by exclusive OR processing to detect the edge portion of each of the signals, an edge detection program is provided for each sensor. Edge detection can be performed on multiple pieces of data at once, regardless of the number of data, by writing and reading data to and from a single memory circuit and performing exclusive OR processing on both data, without having to prepare separate Durhams. The present invention is a signal edge detection device that is suitable for information processing devices such as microcomputers that use software-based signal processing, and can simplify the number of processing steps compared to conventional methods. It has excellent effects such as being able to provide

[Brief explanation of the drawing]

FIG. 1 is a schematic circuit configuration diagram showing an embodiment of the signal edge detection device of the present invention, and FIGS. 2 and 3 are operations for detecting rising and falling edges, respectively, by the control circuit shown in FIG. 1. FIG. 4.51 is a flowchart for explaining a program; FIG. 4.51 is a schematic circuit configuration diagram showing an example of a conventional signal edge detection device; 11. , Signal edge detection device, 12. ,,Memory circuit,13. , , control circuit, +4. ,,edge detection circuit,
! 5. ．． ．． Rising edge detection circuit.

Claims (1)

[Claims] A memory circuit that stores multiple signals sent from multiple sensors as binary data, and a memory circuit that writes the latest data to this memory circuit and stores it until just before the latest data is written. a control circuit that controls the reading of the data written in the memory circuit; and an edge detection circuit that compares the data written to the memory circuit with the data read by exclusive OR processing and detects the edge portion of each signal. Detection device.