JPH10255590A - Switch system and its data fetching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of control IC ports and fetch data with less number of terminals by setting to a low level one of a plurality of scan signal lines connected to an output terminal of a cord switch and a potential of an output signal line constituting a group by pushing down a push button switch. SOLUTION: One contact of four transversal switches 107 of a push button switch 107 of a key switch 106 is connected in common and is connected to terminals SW11 to 14 of an input port 104 through an output signal line. The other contact of the vertical four switches 107 is connected in common and is connected to an output of a cord switch 105, that is terminals SW15 to 18 of the input port 102. When the switch 107 is pressed, a terminal switch 11 of an input port 104 and a terminal SW15 of the input port 104 enter low level, and the switch 107 can be judged to have been pressed. Output ports of the four terminals can be reduced to an output port 103 of one terminal switching a level of a COM terminal of the cord switch 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a switch system including a code switch and a key switch, and a data acquisition method for acquiring data from the system into a control IC.

[0002]

2. Description of the Related Art FIG. 2 is a circuit diagram of a conventional method for loading code switch and key switch data into a control IC.
Shown in In FIG. 2, reference numeral 201 denotes a control IC, reference numeral 202 denotes an input port of a code switch, reference numeral 203 denotes an output port for a scan signal of a key switch, reference numeral 204 denotes an input port for a key switch, reference numeral 205 denotes a code switch,
Reference numeral 206 denotes a key switch, and reference numeral 207 denotes a push button switch. The code switch 205 includes SO1 to SO4
And a COM terminal (common terminal) connected to the ground. Each of the output terminals SO1 to SO4 is supplied with a voltage Vcc, for example, 5 V, through a resistor.
Are connected to the terminals SWI5 to SWI8. The code switch 205 in this example is a 16-position switch. In the position 1, only the terminal SO1 of the code switch 205 is set to the same potential as COM,
SO4 is kept at a high level with a high output impedance. In position 2, 16 combinations of terminals SO1 to SO4 and which are at the ground level (low level) are made such that only the terminal SO2 has the same potential as the COM terminal, and 16 position switches are provided. To correspond to. The input port 202 takes in the data of the code switch depending on which of the input terminals SWI5 to SWI8 is at the ground level.

[0003] The key switch 206 comprises 16 push-button switches 207 in a 4x4 matrix. Each row includes SWI1 to SWI of the input port 204.
Four columns are connected, and each column is connected to output terminals SWS1 to SWS4 of the output port 203. FIG. 3 shows output pulse waveforms from SWS1 to SWS4 of the output port 203. Each terminal outputs a pulse having a period of 4t from Vcc level (high level) to ground level (low level) with a different phase as shown in FIG. Control IC
At 201, the input ports SWI1 to SWI
The terminal 4 is scanned, and if there is a low level input, which key is pressed is detected according to which output port was outputting a pulse during the scan time. For example, when the switch 207 is pressed, the output terminal S
At the time when the pulse is output from WS1, the input terminal SWI1
Becomes low level, it is determined that the switch 207 has been pressed.

[0004]

In the above-mentioned conventional fetching method, eight input terminals and four output terminals are connected to a control IC for data input of a 16-position code switch and 16 key switches. Had to be provided.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a switch system and a data capturing method thereof, in which the number of ports is reduced and the data of a code switch and a key switch can be captured with a smaller number of terminals.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for controlling the potential of several output terminals corresponding to a pressed one of a plurality of position buttons when the button is pressed. A code switch configured to be at the potential of the COM terminal; a plurality of scan signal lines each connected to an output terminal of the code switch; a plurality of output signal lines; and one of the scan signal lines. A push button switch provided for each set of one of the output signal lines and having a function of setting the potentials of both the scan signal lines and the output signal lines constituting the set to a low level when it is pressed; And a switch system characterized by comprising:

According to the present invention, there is provided a data capturing method for capturing data from the switch system, wherein each of an output terminal of the code switch and an output signal line of the key switch is set to a high level via a resistor. In addition to being connected to a power supply having a potential of, the data fetching from the code switch is performed by setting the COM terminal of the code switch to a low level, and when none of the output signal lines of the key switch is at a low level. This is performed by checking which of the output terminals of the code switch and which are at the low level, and taking in the data from the key switch, the COM terminal is set to the high level, and one of the output terminals of the code switch is output.
And a method for acquiring data by checking which one of the output signal lines of the key switch is at a low level.

[0007]

Embodiments of the present invention will be described below in detail. FIG. 1 is a circuit configuration diagram of the present invention,
Is a control IC, reference numeral 102 is an input port of a code switch, reference numeral 103 is an output port for a COM terminal of the code switch, reference numeral 104 is an input port for a key switch, reference numeral 105 is a code switch, reference numeral 106 is a key switch, Reference numeral 107 denotes a push button switch. The code switch 105 is provided with output terminals SO1 to SO4 and a COM terminal. Each of the output terminals SO1 to SO4 is supplied with a voltage Vcc, for example, 5 V, through a resistor, and is connected to the terminals SWI5 to SWI8 of the input port 102 of the control IC 101. COM terminal is
The output port 103 is connected to the terminal SWS1. When data is input from the code switch, the output port 10
3 is set to the ground level (low level), and data is fetched in the same manner as in the conventional method. That is, the output terminals SO1 to SO of the code switch 105 correspond to which of the 16-position switches is pressed.
One or more of O4 has the same potential as the COM terminal.
If the COM terminal is at ground level (low level),
The code switch data is taken in from the input port 102 in exactly the same manner as in the conventional method.

On the other hand, the key switch 106 comprises 16 switches, which are the same as the push button switch 107, in a 4 × 4 matrix. In each row, one contact point of four push button switches in the horizontal direction is commonly connected, and the terminal SWI1 of the input port 104 is connected through a signal output line.
To SWI4. On the other hand, each column
The other one contact point of the four push buttons in the vertical direction is commonly connected, and is connected to the output of the code switch 105, that is, the terminals SWI5 to SWI8 of the input port 102. Also, the terminals SWI1 to SWI of the input port 104
Each of WI4 is supplied with a voltage Vcc, for example, a voltage of 5 V through a resistor similarly to the input port 102. The configuration of the push button switch is slightly different from the switch of the conventional method, and is a switch for lowering both the output signal line connected to the input port 104 and the scan signal line connected to the input port 102 to the ground level (low level). The data is taken in from the key switch 106 by setting the terminal SWS1 of the output port 103 to a high level, that is, the voltage Vcc. Terminal SWS1 of output port 103
Is high, the COM of the code switch 105
Since the terminals are at the high level, that is, the level of the voltage Vcc, the output terminals SO1 to SO4 of the code switch 105
Is always at the Vcc level regardless of which of the position switches of the code switch 105 is pressed. At this time, when the push button switch 107 is pressed, the terminal SWI1 of the input port 104 and the terminal S
WI5 becomes low level, that is, ground level.
Thus, it is determined that the push button switch 107 has been pressed. That is, in the related art, four types of pulses having different phases are transmitted from the output port 203, and it is determined which row of the key switch 106 is pressed by the time at which the pulse is transmitted. In the present invention, it is determined which row of the key switch 106 has been pressed by which input of the input port 102 has become low level. As a result, the conventional four-terminal output port 203 is connected to the CO of the code switch 105.
1 for switching the M terminal between high level and low level
It can be reduced to the output port 103 of the terminal.

Next, terminal SW of output port 103 for detecting code switch 105 and key switch 106
A method for switching S1 will be described. The first method is
As shown in FIG. 4, the output of the SWS1 of the output port 103 is periodically switched between a high level and a low level.
The control flow at this time is shown in FIG. First, the control I shown in FIG.
4 from terminal SWS1 of output port 103 of C101.
Is sent to the COM terminal of the code switch 105 (STEP 51). Next, it is determined whether the pulse is at a low level (STEP 52).
YES at EP52), terminals SWI5 to S of input port 102
It is checked whether any one of WI8 is at the low level (STEP 53). If high level (N in STEP53
O), it is determined that there is no input from the code switch 105, and the process returns to STEP52. If low level (STEP
53), it is determined that there is a possibility of an input from the code switch 105, the COM terminal is held at a low level (STEP 54), and the terminals SWI1 to SWI of the input port 104 are held.
It is checked whether any one of I4 is at the low level (STEP 55). When the level is low (STEP55
YES), key switch 1 instead of code switch 105
06 is determined to have been pressed, and the code switch 10
The process returns to STEP 51 without taking in the data from step 5. If none of the terminals SWI1 to SWI4 is low (NO in STEP 55), it is determined that the data is from the code switch 105, and the input port 102
Fetch data from the terminals SWI5 to SWI8 (STEP
56). The reason why the COM terminal is held at the low level in STEP 54 (STEP 54) is to prevent a high-level pulse from being sent from the terminal SWS1 of the output port 103 during data capture, and to prevent the COM terminal from going high. is there. When the data capture is completed, STEP 51
Return to the COM of the code switch 105
Return to sending to terminal.

In step 52, if the COM terminal is at the high level, that is, if the output from the terminal SWS1 of the output port 103 is at the high level (NO in step 52), the input port 104
It is checked whether any one of the terminals SWI1 to SWI4 is at a low level (STEP 57). If there is no low level (ST
(NO in EP57), it is determined that there is no input from the key switch 106, and the process returns to STEP51. If there is a low level (STEP
(YES at 57), it is determined that there is a correct input from the key switch 106, and the COM terminal is kept at high level (STEP 57).
58), data is fetched from the terminals SWI1 to SWI4 of the input port 104 and the terminals SWI5 to SWI8 of the input port 102 (STEP 59). Here, in step 58, the COM terminal is kept at the high level, that is, the output from the terminal SWS1 of the output port 103 is kept at the high level, because the terminals SWI1 to SWI4 of the input port 104 and the input port 1
This is to prevent the COM terminal from going low while data is being fetched from both of the terminals SWI5 to SWI8. Which key switch is pressed depends on the terminal SWI
Judgment is made based on which of the terminals 1 to SWI4 and the terminals SWI5 to SWI8 has become low level. After importing, STEP
Returning to 51, the periodic pulse is
Send to OM terminal. In this way, data can be correctly captured regardless of which of the code switch 105 and the key switch 106 is pressed.

Next, terminal SW of output port 103 for detecting code switch 105 and key switch 106
A second method for switching S1 will be described. FIG. 6 is a flow chart of the operation.
1 is set to low level, and the COM terminal of the code switch 105 is set to low level (STEP 61). Next, it is checked whether any of the terminals SWI5 to SWI8 of the input port 102 is at a low level (STEP 62). If it is not low (NO in STEP62), code switch 1
05 and the key switch 106 are not pressed,
The detection of whether any of the terminals SWI5 to SWI8 becomes low level is continued (NO loop of STEP62). If any terminal is low level (YE in STEP62)
S), it is checked whether any of the terminals SWI1 to SWI4 of the input port 104 is at a low level (STEP 63).
If none are low (STEP 63
NO), it is determined that the code switch 105 has been pressed, and data is fetched from the terminals SWI5 to SWI8 of the input port 102 (STEP 66), and the process returns to STEP 62. STEP63
If any of them is at the low level, it is determined that the input is from the key switch 106, and the terminal S of the output port 103 is
WS1 is set to high level, and CO of the code switch 105 is set.
Set the M terminal to high level (STEP 64). This means that data input to the input port 102 is
From the key switch 106 only. Then, the terminal SWI of the input port 104
1 to SWI4 and the terminals SWI5 to SW of the input port 104
The data is fetched from I8 (STEP 65), the process returns to STEP 61, and the COM terminal is returned to the low level. Such a C
By changing the level of the OM terminal, the code switch 105,
Whichever of the key switches 106 is pressed, data can be taken in correctly.

Next, the terminal SW of the output port 103 for detecting the code switch 105 and the key switch 106
A third method for switching S1 will be described. In this method, as in the first method described with reference to the flowchart of FIG. 5, a periodic pulse is transmitted from the output port, and the pulse has a high-level time and a low-level time that are almost the same. Some kind of pulse. The outline of the processing is to take in data from the code key 105 only once from the time when the pulse goes low, and to take in data from the key switch 106 only once from the time when the pulse goes high. For this reason, the width of the transmission pulse is guaranteed to be long enough to take in data. FIG. 7 is a flowchart at this time. First, the terminal S of the output port 103 is
From WS1, a pulse that switches between a high level and a low level with a value close to 50% duty is transmitted (STEP 71).
Next, check whether the COM terminal is at low level (STEP
72). If the level is not low (NO in STEP 72), the process waits until the level becomes low (NO loop in STEP 72). If it is at low level (YES at STEP 72), then it waits until the COM terminal goes high (NO loop at STEP 73). This is because the next processing is performed only at the time when the level becomes high. When it goes high (YES in STEP 73), input port 10
It is checked whether any one of the terminals SWI1 to SWI4 is at a low level (STEP 74). If it is not low (NO in STEP 74), it is determined that there is no input from the key switch 106, and it waits for the COM terminal to go low to see the input from the code switch 105 (NO in STEP 76). Loop). If any of the terminals SWI1 to SWI4 is at low level in STEP 74 (ST74
(YES in EP74), it is determined that the input is from the key switch 106, and data is taken in from the terminals SWI1 to SWI4 of the input port 104 and the terminals SWI5 to SWI8 of the input port 104 (STEP 75). It waits for the COM terminal to become low level for taking in (NO loop of STEP76). If the COM terminal goes low (YES in STEP76), the input port 1
It is checked whether any one of the terminals SWI5 to SWI8 of 02 is at the low level (STEP 77). If none are low (NO in STEP77), code switch 1
It is determined that there is no input from the key switch 05, and the process returns to STEP 73 to capture the data of the key switch 106, and waits until the COM terminal goes high (STEP 73). If any of them is at low level (YES in STEP 77), it is checked whether any of the terminals SWI1 to SWI4 of the input port 104 is at low level (STEP 78). If it is at the low level (YES at STEP 78), it is determined that the input is from the key switch 106, and the process returns to STEP 73 to capture the data of the key switch 106, and waits for the COM terminal to go to the high level (STEP 73). . If none of them are at the low level (STEP 78), it is determined that the input is from the code switch 105, and the terminal S of the input port 102 is
Import data from WI5 to SWI8 (STEP 79)
Terminates data capture from code switch 105,
To capture data from the key switch 106, ST
Return to EP73 and wait for the COM terminal to go high. By this repetition, the data capture of the code switch 105 and the key switch 106 is alternately switched.

In the third method, the data of the key switch 106 is fetched only once from the time when the pulse sent from the terminal SWS1 of the output port 103 goes to the high level to the time when the pulse goes to the next low level. Since the data of the code switch 105 is fetched only once from the time when the level changes to the next high level, the switching of the pulse to the high level and the switching of the low level at least once while pressing the switch are performed. Needs to be done. Therefore, the pulse transmitted from the terminal SWS1 of the output port 103 needs to have a pulse width longer than the time required for data capture and a duty of approximately 50%, which is a cycle shorter than the time during which the push button switch is pressed. is there.

As described above, the terminal SWS of the output port 103 for detecting the code switch 105 and the key switch 106
Although three methods have been described for switching 1, the flow processing describes up to data capture, and the subsequent processing, that is, the code switch 105 and the key switch 10
The logic of which switch 6 was pressed is not described, but will be apparent from FIG. Further, it is described that a plurality of push button switches of a key switch are not simultaneously pressed. If there is a possibility that a plurality of buttons may be pressed at the same time, it is sufficient to take in data only when only one input terminal of the input port 102 or 104 is at a low level at the time of taking in data from the key switch. . In the flow, when the switch is pressed once, the data is fetched many times, but the same data is fetched a plurality of times. Therefore, this may be used for processing such as enhancing the reliability of data.

In the configuration shown in FIG. 1, each output terminal of the code switch is grounded when any of the pushbutton switches of the key switch is pressed. However, when the code switch is constituted by an IC such as an encoder in order to represent which of the 16 position switches is pressed by the output of four terminals, when the output terminal is at a high level, High output impedance. Therefore, even if this is forcibly grounded by the push button switch, no overcurrent flows in particular. When the code switch is constituted by a mechanical switch, a diode for protecting an overcurrent when the key switch is grounded is inserted between the output terminals S01 to S04 of the code switch and the key switch. It is good. In the configuration of FIG. 1, the code switch has 16 positions,
Although the key switch has been described as being composed of 4 × 4 push-button switches, it is obvious that the present invention can be applied if the number of output terminals of the code switch is larger than the number of scan signal lines of the key switch.

[0016]

According to the present invention, the number of ports of the control IC can be reduced. Therefore, the following effects can be obtained. (1) An IC having a small number of terminals can be used as a control IC. When the same IC is used, there is an advantage that the port can be used for another control. (2) In many cases, the control IC and the switch are mounted on different boards. At this time, a connector having a small number of pins for connecting the boards can be selected, which is advantageous in mounting. (3) Since the number of signal lines connected to the port is reduced,
Routing of signal lines is facilitated.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of the present invention.

FIG. 2 is a circuit configuration diagram of a conventional technique.

FIG. 3 is a diagram showing an output pulse waveform from an output port according to the related art.

FIG. 4 is a diagram showing an output pulse waveform from an output port of the present invention.

FIG. 5 is a flowchart of a first switching method of taking in data from a code switch and a key switch.

FIG. 6 is a flowchart of a second switching method of data acquisition from a code switch and a key switch.

FIG. 7 is a flowchart of a third switching method for taking in data from a code switch and a key switch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Control IC 102 Code switch input port 103 Code switch COM terminal output port 104 Key switch input port 105 Code switch 106 Key switch 107 Pushbutton switch 201 Control IC 202 Code switch input port 203 Key switch Output port 204 for key switch Input port for key switch 205 Code switch 206 Key switch 207 Push button switch

Claims (5)

[Claims] 1. A code switch configured such that when one of a plurality of position buttons is pressed, the potential of some output terminals corresponding to the pressed button becomes the potential of the COM terminal. A plurality of scan signal lines each connected to the output terminal of the code switch, a plurality of output signal lines, and a set of one of the scan signal lines and one of the output signal lines are provided for each set. A switch system comprising: a push button switch having a function of setting the potentials of both the scan signal lines and the output signal lines constituting the set to a low level when pressed. 2. A data capturing method for capturing data from the switch system according to claim 1, wherein each of an output terminal of the code switch and an output signal line of the key switch is at a high level via a resistor. In addition to being connected to a power supply having a potential of, the data fetch from the code switch is performed by setting the COM terminal of the code switch to a low level, and when none of the output signal lines of the key switch is at a low level. This is performed by checking which of the output terminals of the code switch and which are at the low level.
A data capturing method, wherein the M terminal is set to a high level, and the method is performed by checking which one of the output terminals of the code switch and one of the output signal lines of the key switch are at a low level. 3. In a data input waiting state, the COM terminal of the code switch is switched between a high level and a low level at a constant period, and when the COM terminal becomes a low level with the periodic level switching, the code switch of the code switch is turned off. When it is detected that at least one of the output terminals is at a low level,
The COM terminal is held at a low level, and in this state, data is taken in from the code switch. When the COM terminal goes to a high level with periodic level switching in the input waiting state, the key switch is turned off. 3. The device according to claim 2, wherein when one of the output signal lines is detected to be at a low level, the COM terminal is held at a high level, and in this state, data is taken in from the key switch. Data capture method. 4. In a data input waiting state, the COM terminal of the code switch is held at a low level, and in this state, if any of the output signal lines of the key switch is at a high level, data from the code switch is transmitted. When the COM terminal is at a low level and one of the output signal lines of the key switch is at a low level, the COM terminal is held at a high level, and in this state, data from the key switch is transferred. 3. The data capturing method according to claim 2, wherein the capturing is performed. 5. In a data input wait state, the COM terminal of the code switch is switched between a high level and a low level at a constant period, and a time for holding the high and low levels is longer than a time required for data capture. In accordance with the periodic level switching, data is taken in from the key switch only once until the COM terminal goes to a high level and then goes to a low level. 3. The data capturing method according to claim 2, wherein the data capturing from the code switch is performed only once before the COM terminal goes low and then goes high.