KR0165208B1 - Keyboard incoding device and method thereof - Google Patents

Abstract

1. The technical field to which the invention described in the claims belongs:

Keyboard Encoding Device and Method.

2. The technical problem the invention is trying to solve:

Conventionally, in order to detect a key input, a key strobe signal along a line is continuously output or two ports have to be converted into an input port and an output port to read the coordinates of a pressed key. In the first case, the key strobing signal is a source of electromagnetic interference, which is often a problem in the electronic device. In the second case, a large current is consumed when the input and output ports are switched because the key is recognized while the input and output ports are toggled. It became.

3. Summary of the Solution of the Invention:

Both ports in row and column are used as input ports, and the pull-up voltage is provided in the row and column and the ground switch is further provided in the key switch to provide the pull-up voltage supplied when the key switch is pressed. Grounding results in a change in voltage level. The change of the voltage level is detected to generate an interrupt, and the coordinates of the specific key pressed by the changed row and column coordinates are known. Therefore, the cause of electromagnetic interference is eliminated, and there is no need to convert to the output port, so that the excessive consumption of current is eliminated, and the key can be recognized immediately when the key is pressed.

4. Important uses of the invention:

Keyboard encoding device

Description

Keyboard Encoding Device and Method

1 is a block diagram of a keyboard encoding apparatus connected to a conventional key matrix.

2 is a signal diagram output to the output terminal of FIG.

3 is a block diagram of a keyboard encoding apparatus connected to a conventional key matrix.

4 is a block diagram of a keyboard encoding apparatus connected to key metrics according to the present invention.

5 is a detailed block diagram of a keyboard encoding apparatus according to the present invention.

6 is a structural diagram of a switch for performing a switching operation according to the pressing of a key in the key matrix according to the present invention.

* Explanation of symbols for main parts of the drawings

410: control unit 412: A port

414: port B 416: key metrics

420: keyswitch 510, 512: buffer

514: filter 516: edge detector

518: interrupt generator

The present invention relates to a keyboard encoding apparatus and method, and more particularly, to an apparatus and method for encoding a specific key input by detecting a signal generated by pressing a specific key using two ports as input ports.

The prior art will be described with reference to FIGS. 1, 2, 3.

The block diagram of FIG. 1 is a keyboard interface controller 110 having a key signal input port X ₁ -Xn and a key signal output port Y ₁ -Yn, and a key switch 114 corresponding to a plurality of key contacts. It consists of key metrics 112 having a.

In the device having the above-described configuration, a key input sensing method may be performed by sequentially outputting the keystroke signal shown in FIG. 2 to the key signal output ports Y _{1 to} Yn of the keyboard interrupt control apparatus 110. When one key switch 114 constituting the key metrics 112 is pressed, a key strobe signal input to the key signal input ports X _{1 to} X n is read to check the pressed key.

For example, the keyboard interface controller 110 may include a pull-up resistor externally or internally so as to provide a logic high signal to the signal input ports X _{1 to} Xn. Signal is output, and a logic low signal is output to the key signal output ports (Y _{1 to} Y n). If there is no input of a specific key of the key metrics 112, the logic high state will always be maintained in the key signal input ports X ₁ -Xn.

However, when the key of the coordinate corresponding to X ₁ -Yn is pressed, the key strobing signal output through the key signal output port corresponding to the key signal input port Yn of X ₁ will be detected. Accordingly, it is detected that the key having the coordinates (X _1- Yn) is pressed.

In addition, the block diagram of FIG. 3 shows a keyboard interface controller 310 having two ports 310a and 310b which both use a key signal input port and a key signal output port, and a key switch 314 corresponding to a plurality of key contacts. It consists of key metrics 312 having a.

For example, referring to FIG. 3, the first port 310a connected to the lines X ₁ -Xn corresponding to the rows of the key metrics 312 is placed in an output port state, The second port 310b connected to the corresponding line Y ₁ -Yn is placed in an input port state. Each port 310a, b provides a logic high or low signal in opposition to the rows of the key metrics 312. In the above state, when the key switch 314 is closed by pressing a specific key, the second port 310b first reads a signal corresponding to the row from the first port 310a. In addition, when a line of a line where a specific key is pressed is detected, the first port 310a is converted into an input port, and the second port 310b is converted into an output port. Each of the ports 310a and b provides a logic high or low signal in a row and a column opposite to each other, and the first port 310a provides a signal corresponding to a column in the second port ( 310b).

However, a key strobing signal continuously output to a line to detect a key input through the device having the structure as shown in FIG. 1 is a source of electromagnetic interference, which is often a problem in electronic devices.

In addition, when detecting a key input through the device having the structure as shown in FIG. 3, the input / output combined port should be configured, and the state of the port corresponding to the row and column may be input or obtained to obtain the coordinates of the corresponding key switch pressed. There is a problem in that a large current is consumed due to the conversion to the output port.

Accordingly, an object of the present invention is to provide an apparatus and method for providing a ground terminal in a key switch and using two ports as input ports for sensing that a key is pressed.

Another object of the present invention is to supply a constant pull-up voltage to the key metrics from two ports connected to the row and column of the key matrix, to detect the key input as a change in the pull-up voltage according to the pressing of a specific key and To provide a method.

Hereinafter, a configuration of an apparatus for performing the present invention will be described in detail with reference to the accompanying drawings.

4 is a block diagram of a keyboard encoding apparatus connected to key metrics according to the present invention.

The key metrics 416 is composed of a plurality of row lines and column lines, and the key switch 420 is installed at a point where the row lines and the column lines overlap.

A port 412 is a line (X ₁ -Xn) corresponding to the row of the key matrix 416 connected to the pull line (X ₁ -Xn) - supplying-up voltage, the specific key is pressed The column line is sensed by the key signals KXX _{1 to} KXXn inputted accordingly, and provided to the controller 410.

B port 414, and the line (Y ₁ -Yn) for the column of the key matrix 416 connected to the pull line (Y ₁ -Yn) - supplying-up voltage, the specific key is pressed The row line is sensed by the key signals KSY ₁ -KSYn input accordingly and provided to the controller 410.

The controller 410 finds the coordinates of the key switch 420 that is pressed by receiving the detection signals according to the rows and columns from the A port 412 and the B port 414 through the bus 418.

5 is a detailed block diagram of a keyboard encoding apparatus according to the present invention, in which the pull-up resistors R1 and R2 supply the pull-up voltage V _DD to a plurality of row and column lines to adjust the pull-up voltage level. Keep it.

The buffers 510 and 512 detect a key signal Ksxn input as a specific key is pressed and provide the same to the controller 410 through the bus 418.

The filter 514 removes noise components from the key input signals of the rows or columns output from the buffers 510 and 512.

The edge detector 518 detects an edge from the signal output from the filter 514.

The interrupt generator 518 generates an interrupt to the controller 410 when a specific key is pressed and a logic high signal is input from the edge detector 518. In addition, the interrupt generator 518 is configured by a register capable of reading or writing data to the controller 410.

The interrupt device 520 includes the filter 514, the edge detector 516, and the interrupt generator 518 and is connected to one buffer output terminal of the two buffers 510 and 612.

A port 412 shown in FIG. 4 includes the pull-up resistor R1 and a buffer 510. When an interrupt occurs in the A port 412, the interrupt device 520 causes the buffer. 510 is connected to the output terminal.

In addition, the B port 414 shown in the fourth is composed of the pull-up resistor R2 and the buffer 512. When an interrupt occurs in the A port 512, the interrupt device 520 is It is connected to the output terminal of the buffer 510.

6 is a structural diagram of a key switch performing a switching operation according to the pressing of a key in key metrics according to the present invention.

FIG. 6a illustrates that a ground terminal is inserted between a row terminal connected to the A port 412 and a column terminal connected to the B port 414 on a printed circuit board (PCB) to press the switch 610-a. The structure of the key switch 420 is configured such that the row and column terminals are connected to the ground terminal.

FIG. 6B illustrates that the switch 610-b is grounded, and when the switch is pressed according to a key input, both the terminal connected to the A port 412 and the column terminal connected to the B port 414 on the PCB (Printed Circuit Board) are grounded. The structure of the key switch 420 configured to be illustrated is shown.

Therefore, an embodiment of the present invention will be described in detail with reference to FIGS. 4, 5, and 6.

The pull-up voltage supplied through the pull-up resistors R1 and R2 is uniformly provided in the row and column lines of the key metrics 416. At this time, when a specific key is pressed, the pull-up voltage supplied through the pull-up resistors R1 and R2 flows through the ground terminal provided in the key switch 420 having the structure shown in FIG. . As a result, the voltage level of the row and column of the pressed specific key position is set to the high level by the pull-up resistors R1 and R2. The low level voltage is detected in the buffers 510 and 512, and the buffers 510 and 512 output the detection signal according to the detected voltage level to the interrupt device 520. The detection signals output from the buffers 510 and 512 are input to a filter 514 provided in the interrupt device 520 to output a signal from which noise is removed. The signal output through the filter 514 is input to the edge detector 516. When an edge is detected by the edge detector 516, a logic high signal is output to set the interrupt generator 518. Accordingly, the interrupt generator 518 generates an interrupt according to the logic high signal and proceeds to an interrupt service routine.

When the interrupt service routine is set, the controller 410 reads coordinate values of a row of a specific key pressed from the A port 412 having an input line of X ₁ -Xn, and has an input line of Y ₁ -Yn. Read the coordinate value of the column of the specific key pressed from the B port 414.

In addition, the controller 410 may read coordinates of a specific key pressed according to a detection signal provided from the buffers 510 and 512 provided in the A port 412 and the B port 414.

When the key metrics 416 are configured with the key switch 420 shown in FIG. 6A and the key metrics 418 are configured with the key switch 420 shown in FIG. The method of detection is the same. In addition, when the interrupt device 520 is connected to the output terminal of the A port 412 and when connected to the B port 414, the interrupt is generated in the same manner.

As described above, the present invention has the effect of detecting the coordinates of a particular key pressed more quickly by using both the lines of the lines and columns constituting the key metrics as input lines, and using both ports as input ports. .

Claims (8)

1. A keyed encoding device for detecting a press of a specific key from key metrics having a plurality of row lines and column lines, the key port encoding apparatus comprising: a first port for detecting a key signal of a row input as a specific key is pressed; A second port for detecting a key signal of a column inputted as pressed, an interrupt generating means for generating an interrupt signal in response to a signal of a row detected from the first port, and detected from the first and second ports Keyboard encoding device, characterized in that consisting of the sensing means for detecting the coordinates of the specific key pressed in accordance with the detection signal. The method of claim 1, wherein the first port comprises: a voltage supply unit for supplying a pull-up voltage to the row line of the key matrix, and a voltage level that is converted when a specific key is pressed to correspond to row coordinates; Keyboard encoding apparatus comprising a first buffer for providing a signal. The method of claim 1, wherein the second port, the voltage supply unit for supplying a pull-up voltage to the column line of the key matrix, and detecting the voltage level to be converted when a specific key is pressed to correspond to the coordinates of the column Keyboard encoding apparatus comprising a second buffer for providing a signal. The method of claim 2, wherein the interrupt generating means comprises: a filter for removing a noise component from a signal output from the first buffer, an edge detector for detecting an edge from a signal output from the filter, and an edge at the edge detector. And a generator for generating an interrupt when detected. 4. The method of claim 3, wherein the interrupt generating means comprises: a filter for removing noise components from a detection signal output from the second buffer, an edge detector for detecting an edge from a signal output from the filter, and an edge at the edge detector. And a generator for generating an interrupt when is detected. The key switch according to claim 2 or 3, wherein the specific key has a ground terminal between two terminals connected to row and column lines so that the row and column lines are grounded when the switch is pressed. Keyboard encoding device characterized in that consisting of. The key switch according to claim 2 or 3, wherein the specific key has a structure in which the row and column lines are grounded when the switch is pressed on two terminals to which the row and column lines are connected and the switch itself is grounded. Keyboard encoding device characterized in that consisting of. A method for detecting a specific key press in a keyboard encoding apparatus, comprising: a first process of detecting a change in a pull-up voltage level supplied to a row and a column line at a predetermined level and generating a detection signal; and detecting according to a specific key press A second process of performing an interrupt when a signal is generated and a third process of detecting coordinates of a specific key pressed by receiving a detection signal generated in the first process according to the interrupt .