JPH054031Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is widely used as an input device for information processing devices, and particularly relates to a stall prevention keyboard controlled by a microcomputer.

[Conventional Description] Conventionally, the following method was used to send data input on a keyboard to a host device of the keyboard.

That is, data entered on a keyboard is scanned by a microcomputer via a keyboard matrix. The contents were then processed by firmware installed in the microcomputer and sent to the host device.

[Problems to be Solved] The conventional keyboard described above was controlled by a microcomputer arm.

Therefore, when a malfunction occurs in the firmware, the host device cannot recognize the state, and in some cases, there is a problem in that input from the keyboard becomes impossible.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a stall-preventing keyboard that allows a host device to recognize a malfunctioning state of firmware.

[Means for solving problems] In order to achieve the above object, the present invention provides keyboard clock output firmware that is installed in a microcomputer that controls a keyboard and outputs a keyboard clock that indicates that the keyboard is operating normally. and a keyboard interface for transmitting the keyboard clock to a higher-level device of the keyboard, and is configured to be restarted by a reset signal from the higher-level device that detects a stall of the keyboard when the keyboard clock stops.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the overall structure of a stall prevention keyboard according to an embodiment of the present invention, and FIG. 2 is a flowchart of firmware in the keyboard of this embodiment.

In the drawing, 1 is a keyboard matrix in which keys are arranged in a matrix, 2 is a keyboard controller consisting of a microcomputer that controls the operation of the keyboard, 3 is a keyboard interface having an interface circuit with a host device, and 4 is a host device. It is a connector for connecting with. The keyboard controller 2 is also equipped with keyboard clock output firmware 7 for outputting a keyboard clock.

In a keyboard with such a configuration,
When the keyboard is operating normally, the keyboard clock output firmware 7 outputs a keyboard clock. This keyboard clock is received by the host device via the keyboard interface 3. As a result, the host device
While receiving the keyboard clock, it is recognized that the keyboard is operating normally.

If a malfunction occurs in the firmware, the keyboard clock output firmware 7 will not output the keyboard clock. Therefore, since the keyboard clock is not sent to the host device via the keyboard interface 3, the host device detects the keyboard stall. The host device that detects the stall resets the keyboard and returns the keyboard to its initial state, allowing the keyboard to be restarted.

Note that the general operation of the firmware in the keyboard in this embodiment will be explained with reference to FIG.

That is, the initial state of the keyboard is determined by the keyboard initializer firmware 5. Data input via the keyboard matrix 1 is detected by the key scanner armware 6 as ON/OFF of keys. If these firmwares are operating normally, the keyboard clock output firmware 7 outputs a keyboard clock. On the other hand, the keys input in keyboard controller 2
The key ON/OFF discrimination firmware detects when the ON/OFF state changes from ON to OFF or from OFF to ON. When the ON/OFF state of the key changes, the key code is output from the key code output firmware 9.

The data processed in this way is sent to the host device as keyboard data.

[Effects of the invention] As explained above, this invention implements firmware that outputs the keyboard clock.
A stall can be detected based on the presence or absence of the output, and the keyboard stall can be effectively prevented.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the overall structure of a stall prevention keyboard according to an embodiment of the present invention, and FIG. 2 is a flowchart of the firmware of the keyboard of this embodiment. 2...Keyboard controller, 3...Keyboard interface, 7...Keyboard clock output firmware.

Claims (1)

[Scope of utility model registration request] It is installed in the microcomputer that controls the keyboard, and includes keyboard clock output firmware that outputs a keyboard clock indicating that the keyboard is operating normally, and a keyboard interface that sends the keyboard clock to the host device of the keyboard. The stall prevention keyboard is characterized in that the keyboard restarts in response to a reset signal from a host device that detects a keyboard stall when the keyboard clock stops.