JP3393973B2 - Key scan method and 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 key scanning method and apparatus for detecting an operation state of a plurality of keys by scanning a plurality of keys, and in particular, reduction of wasteful current consumption accompanying the key scanning is realized. In addition, the present invention relates to a key scan method and device that can reduce the influence of this key scan on other devices.

[0002]

2. Description of the Related Art Generally, a plurality of keys are arranged in, for example, a matrix, and the plurality of keys arranged in the matrix are scanned to detect the operation state of the plurality of keys to determine the operation state of the plurality of keys. A key scanning method and device for inputting corresponding information are adopted in various industrial equipments, mobile wireless phones, and the like.

By the way, conventionally, in this type of key scanning method and apparatus, the operation state of the plurality of keys is detected by periodically scanning the plurality of keys.

However, in the above-described conventional key scanning method and device, a plurality of keys are constantly scanned regardless of whether or not there is a key operation. In particular, a portable wireless telephone driven by a battery causes wasteful consumption of the battery, which shortens the life of the battery.

Further, when a key is operated, the key operation is performed by a high-speed clock. Therefore, when adopting a structure in which a plurality of keys are regularly scanned like the above-mentioned conventional method and apparatus, this key operation is performed. Therefore, the high-speed clock may have an adverse effect.

[0006] For example, TDMA (Time Divis)
In a mobile wireless telephone or the like which adopts the ion multiple access method, a key operation may be performed by the high-speed clock within the transmission slot period of the mobile wireless telephone, in which case the reception sensitivity of the mobile wireless telephone deteriorates. There was a problem of doing.

[0007]

As described above, in the conventional key scanning method and apparatus of this type, a plurality of keys are constantly scanned regardless of whether or not there is a key operation. This key operation consumes useless current consumption, and there is a problem that the high-speed clock may adversely affect other devices due to the key operation.

Therefore, an object of the present invention is to provide a key scanning method and device which realizes reduction of useless current consumption due to key scanning and also enables reduction of influence of this key scanning on other devices. And

[0009]

In order to achieve the above-mentioned object, the invention of claim 1 is a key scanning method for detecting an operation state of a plurality of keys by scanning a plurality of keys of a wireless device. The operation of any one of the plurality of keys is detected, the reception timing of the wireless signal is detected, and the reception timing of the detected wireless signal is removed in response to the detection of the key operation. Is started, and the operation states of the plurality of keys detected by the scanning are temporarily stored and output.

According to a second aspect of the present invention, in a key scanning device which detects an operating state of a plurality of keys by scanning a plurality of keys of a wireless device, a scanning timing signal for scanning the plurality of keys is generated. Timing generating means, a key operation detecting means for detecting an operation of any one of the plurality of keys, a reception timing detecting means for detecting a reception timing of a radio signal, and a detection output of the key operation detecting means. When the reception timing detection means detects the reception timing of the radio signal while activating the timing generation means, the activation control means for stopping the timing generation means and the activation by the timing generation means are detected. Storage means for temporarily storing the operation states of the plurality of keys; and the plurality of keys stored in the storage means. Characterized by comprising an output means for outputting the operation state.

[0011]

[0012]

[0013]

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A key scanning method and device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of a key scanning device for a TDMA type portable radio telephone constructed by applying the key scanning method and device according to the present invention.

In FIG. 1, the key scanning device is
The operation state of a total of 32 keys arranged on a key pattern 10 arranged in a matrix of 8 rows and 4 columns including dial keys of this portable radio telephone is detected, and the detection result is obtained as a result of this detection. CPU that controls the overall operation of the
(Central processing unit) 18 is input.

The operation state of the keys arranged on the key pattern 10 is detected based on the timing signal output from the timing generation circuit 11.

In a state where all the keys arranged on the key pattern 10 are not operated, the timing generation circuit 11 has drivers 1-1 to 1-8 provided corresponding to the row lines of the key pattern 10. Is activated (turns on the open drain buffer).

When any one of the keys arranged on the key pattern 10 is operated in this state, this operation is detected by the key input detection circuit 12 formed of a negative logic OR circuit.

That is, pull-up resistors 2-1 to 2-4 are connected to the column lines of the key pattern 10, respectively. Therefore, when any key on the key pattern 10 is operated in this state, the drivers 1-1 to 1-8 corresponding to the operated key and the key pattern 1 are operated.
0, a current flows through the pull-up resistors 2-1 to 2-4, which causes the operated key of the waveform shaping circuits 3-1 to 3-4 connected to the column line of the key pattern 10. The key operation signal is input to the inputs of the waveform shaping circuits 3-1 to 3-4 corresponding to.

The key operation signal is waveform-shaped by the corresponding waveform shaping circuits 3-1 to 3-4, and the key input detection circuit 1
Entered in 2. As a result, when any of the keys arranged on the key pattern 10 is operated, the key input detection circuit 12 outputs a key detection signal indicating that any of the keys arranged on the key pattern 10 has been operated. Is output, and this key detection signal is input to the timing generation circuit 11.

In addition to the above key detection signal, the timing generation circuit 11 includes a TDMA type reception section timing circuit 21.
A reception slot timing signal corresponding to the reception slot of this portable radio telephone is input from the terminal 3.

When the timing generation circuit 11 inputs a key detection signal from the key input detection circuit 12 indicating that one of the keys arranged on the key pattern 10 has been operated, the timing generation circuit 11 inputs it from the TDMA type reception section timing circuit 213. Based on the reception slot timing signal that is activated, it is activated so as to avoid the reception slot of this portable radio telephone,
The keys arranged on the key pattern 10 are scanned.

The scanning of the keys arranged on the key pattern 10 by the timing generation circuit 11 is performed by the key pattern 10
Driver provided for each row line 1-
This is performed by sequentially controlling 1 to 1-8 to be active.

By the scanning by the timing generating circuit 11, a key operation signal is generated on the column line of the key pattern 10 corresponding to the operated key among the keys arranged on the key pattern 10, and this key operation signal corresponds to Waveform shaping circuit 3-1 including a Schmitt trigger circuit
It is input to the latch circuit 14 via 3-4.

The scanning timing signal from the timing generation circuit 11 is input to the latch circuit 14. Therefore, in the latch circuit 14, the waveform shaping circuits 3-1 to 3-4
The key operated on the key pattern 10 is specified on the basis of the key operation signal input from and the scanning timing signal input from the timing generation circuit 11, and information indicating the specified operation key is stored.

In this way, the timing generation circuit 11
When the scanning of the key operated on the key pattern 10 is completed, the timing generation circuit 11 causes the interrupt generation circuit 1 to operate.
An interrupt request signal is output to 5.

The interrupt generation circuit 15 responds to the interrupt request signal from the timing generation circuit 11 and controls the overall operation of the portable radio telephone 1 (CPU (Central Processing Unit)).
An interrupt signal is output to the 8 through the interrupt line 16.

The CPU (central processing unit) 18 that has received the interrupt signal from the interrupt generation circuit 15 is
The information indicating the key operated on the key pattern 10 stored in the latch circuit 14 is fetched via the data bus 17 of the (central processing unit) 18, and the processing based on the fetched information is performed.

FIG. 2 is a timing chart showing the operation of the above key scanning device.

In FIG. 2, (a) shows the slot structure of this TDMA type portable radio telephone. Figure 2 (a)
, "I" indicates an idle slot of this mobile wireless telephone, "R" indicates a receiving slot of this mobile wireless telephone, and "T" indicates a transmission slot of this mobile wireless telephone.

The TDMA receiver timing circuit 213 shown in FIG. 1 outputs a reception slot timing signal corresponding to the reception slot "R" of the portable radio telephone shown in FIG. Circuit 11
Entered in.

When the key input detection circuit 12 shown in FIG. 1 detects that one of the keys arranged on the key pattern 10 is operated, the key input detection circuit 12 changes the state shown in FIG. 2 (b). The key detection signal shown is output and input to the timing generation circuit 11.

When the key generation signal is input from the key input detection circuit 12 (see FIG. 2B), the timing generation circuit 11 receives the reception slot timing signal (FIG. 2 ( a)
Based on the reference), the cellular phone is activated so as to avoid the reception slot “R”, and the keys arranged on the key pattern 10 are scanned.

It should be noted that one cycle ts of the slot configuration of this TDMA type portable radio telephone shown in FIG. 2A is, for example, 20 ms. Compared with the time of this one period ts, this portable radio telephone of the user is The key pressing time is sufficiently long, as shown in FIG.
That is, the time when the key detection signal is at the high level is longer than the cycle ts. Therefore, in this portable radio telephone, by utilizing this relation, the key slot 10 is arranged on the key pattern 10 while avoiding the reception slot "R" while the key detection signal is at the high level, that is, while the key is pressed once. It is possible to detect a single key press even if the key is scanned.

Specifically, the timing generation circuit 11 is
When the key detection signal is input from the key input detection circuit 12, it is activated at the timing when the next reception slot “R” input from the TDMA type reception section timing circuit 213 ends, and as shown in FIG. Key pattern 10
Perform a scan of the keys located above.

The key scanning by the timing generating circuit 11 is performed by sequentially sequentially controlling the drivers 1-1 to 1-8 provided corresponding to the row lines of the key pattern 10 to be active.

This state is shown in FIG. 2 (d). That is, the timing generation circuit 11 first includes the driver 1 provided corresponding to the first row line of the key pattern 10.
-1 output the signal to low level, other driver 1-2
The signals output to 1 to 8 are set to a high level to actively control only the driver 1-1 corresponding to the first row line of the key pattern 10. In this state, key pattern 1
The operation states of the four keys arranged on the first row line of 0 are detected.

That is, in this state, the key pattern 10
Of the keys arranged on the first row line of the driver, the driver 1-1, the key pattern 10 corresponding to the operated key, and the pull-up resistors 2-1 to 2-1.
A current flows through 2-4, a current flows through the key pattern 10 corresponding to the operated key, the column line of the key pattern 10 corresponding to the operated key becomes low level, and this is the key operation. The signal is input to the latch circuit 14 via the corresponding waveform shaping circuits 3-1 to 3-4.

At this time, since the scanning timing signal indicating the scanning timing of the first row of the key pattern 10 from the timing generation circuit 11 is input to the latch circuit 14, the latch circuit 14 and the waveform shaping circuit 3 are input. -1 to 3
It is possible to specify the scanning states of the four keys arranged in the first row on the key pattern 10 based on the signal input from -4 and the scanning timing signal input from the timing generation circuit 11.

Similarly, the timing generation circuit 11 includes the driver 1 corresponding to the second to eighth rows of the key pattern 10.
The signals output to −2 to 1-8 are sequentially set to the low level, and only the drivers 1-2 to 1-8 corresponding to the second row to the eighth row of the key pattern 10 are sequentially activated to be activated, and the key pattern 10 The operation state of each of the four keys arranged on the second row to the eighth row is sequentially detected.

In this way, the timing generation circuit 11
When the scanning of the key operated on the key pattern 10 is completed, the timing generation circuit 11 causes the interrupt generation circuit 1 to operate.
5, the interrupt request signal shown in (e) of FIG. 2 is output.

The interrupt generation circuit 15 outputs an interrupt signal to the CPU (central processing unit) 18 in response to the interrupt request signal, whereby the CPU (central processing unit) 18 is activated.
Captures information indicating a key operated on the key pattern 10 stored in the latch circuit 14 via the data bus 17.

According to such a configuration, the key pattern 1
Since the scan of 0 is performed only when there is a key operated on the key pattern 10, it is possible to realize the reduction of the unnecessary current consumption accompanying the key scan.

Further, since the scanning of the key pattern 10 is performed so as to avoid the reception slot "R" of the portable radio telephone, the reception sensitivity of the portable radio telephone due to the scanning of the key pattern 10 is deteriorated. The inconvenience of being lost can be eliminated.

In the timing chart shown in FIG. 2, when the key input detection circuit 12 outputs a key detection signal indicating that one of the keys arranged on the key pattern 10 has been operated, The timing generation circuit 11 is executed at the timing when the next reception slot “R” input from the TDMA type reception section timing circuit 213 is completed.
The timing generator circuit 11 is configured to start up and scan the keys arranged on the key pattern 10.
The activation timing of is not limited to the timing shown in FIG. 2 as long as it is activated so as to avoid the reception slot “R” of the portable radio telephone.

[0047]

As described above, according to the present invention,
When any one of the plurality of keys to be scanned is operated, the scanning means for scanning the plurality of keys is activated to scan the plurality of keys. It is possible to realize a reduction in useless current consumption due to scanning, and since this key scanning is performed, for example, so as to avoid the reception slot of the portable wireless telephone, the present invention is applied to the key of the portable wireless telephone. When applied to the pad key scanning, the disadvantage that the reception sensitivity of this portable radio telephone is deteriorated by the key scanning of the keypad can be solved, and further, unnecessary current consumption due to the key scanning is eliminated. Since it is reduced, the battery life of this portable radio telephone can be extended.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a key scanning device for a TDMA-TDD mobile radio telephone configured by applying a key scanning method and device according to the present invention.

FIG. 2 is a timing chart showing the operation of the key scanning device of the TDMA type portable wireless telephone shown in FIG.

[Explanation of symbols]

1-1 to 1-8 driver 2-1 to 2-4 Pull-up resistor 3-1 to 3-4 waveform shaping circuit 10 key pattern 11 Timing generation circuit 12 Key input detection circuit 13 TDMA system receiver timing circuit 14 Latch circuit 15 Interrupt generation circuit 16 interrupt lines 17 data bus lines 18 CPU (central processing unit)

Continuation of the front page (56) Reference JP-A-1-260520 (JP, A) JP-A-8-221172 (JP, A) JP-A-4-81918 (JP, A) JP-A-5-130027 (JP , A) Japanese Patent Laid-Open No. 4-21220 (JP, A) Japanese Patent Laid-Open No. 9-9315 (JP, A) Actual Kaihei 5-40928 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G06F 3/02-3/027 H04M 1/00-1/253 H04B 7/24-7/26

Claims (2)

(57) [Claims] 1. A key scanning method for detecting an operation state of a plurality of keys by scanning a plurality of keys of a wireless device, wherein the operation of any one of the plurality of keys is detected, and A signal reception timing is detected, and in response to the detection of the key operation, the detection timing of the detected wireless signal is removed to start scanning of the plurality of keys, and the plurality of keys detected by the scanning are detected. A key scanning method characterized by temporarily storing and outputting an operation state. 2. A key scanning device for detecting an operation state of a plurality of keys by scanning a plurality of keys of a wireless device, the timing generating means generating a scanning timing signal for scanning the plurality of keys, Key operation detecting means for detecting operation of any one of a plurality of keys, reception timing detecting means for detecting reception timing of a wireless signal, and starting the timing generating means in response to a detection output of the key operation detecting means. In addition, when the reception timing detection means detects the reception timing of the radio signal, the activation control means for stopping the timing generation means, and the operation state of the plurality of keys detected by the activation of the timing generation means And a storage unit for temporarily storing the operation status of the plurality of keys stored in the storage unit. A key scanning device, comprising: