JP2686763B2 - Segment type display device - Google Patents

Description

The present invention relates to a display system of a segment type display, and more specifically, a segment such as a 7-segment LED used for a display panel of a system such as an information processing device. The present invention relates to a segment type display device having a type display.

(Prior Art) FIG. 2 is a diagram showing an example of a conventional display panel. In this figure, 1 is a display panel, 2 is a 7-segment LED provided on the display panel 1, 3 is a display selection switch such as a 7-segment LED, and 8 is light emission for displaying the system status of an information processing apparatus or the like. Diode (LE
D). In the conventional information processing apparatus, the system status is displayed by the display panel 1 as shown in this figure. By the way, the 7-segment LED2 has 7 LEDs inside.
And a display device that displays the character information by forming a combination of LED lights.

Figure 6 is a drawing showing this 7-segment LED.
(1) shows its internal circuit diagram, and (2) shows its external view.
In this figure, a to g indicate signal lines connected to the LEDs of each segment. The symbols A to G in FIG. 6 (1)
Correspond to the LEDs A to G shown in FIG. 6 (2).
For example, in order to display the code "1", B and C LEDs are turned on by passing a current through the signal line b and the signal line c shown in FIG. 6 (1). As can be seen from FIG. 6 (2), when the B and C LEDs are turned on, the code becomes "1" (indicated by diagonal lines). The 7-segment LED 2 thus forms the character information and displays the character.

The display panel shown in FIG. 2 relates to a processor system including two CPUs and has the following display functions.

First, the states of the two CPUs CPU0 and CPU1 can be displayed by the LED 8, and the states of RUN, WAIT, STOP, and ALM can be displayed. The lighting conditions of each LED 8 are as follows.

RUN: Lights when the CPU is in the instruction execution state.

WAIT: Lights when the CPU is in a waiting state.

STOP: Lights when the CPU is stopped.

ALM: Lights when the CPU is in the failure detection status.

In addition, the display selection switch 3 by the 7-segment LED2
The display mode selected by, that is, two states of the CPU0 stop code and the CPU1 stop code can be displayed. The display selection switch 3 is a rotary switch, and the 7-segment LED 2 displays its contents in a 4-digit hexadecimal code according to the selected display mode. The CPU0 stop code and the CPU1 stop code are stop codes when the CPU stops.

Next, the operation of the display circuit of the display panel of FIG. 2 will be described with reference to FIG. FIG. 3 is a block diagram of the display circuit of FIG. In this figure, 4 and 5 are CPUs
4 is CPU0, 5 is CPU1, 6 is a CPU monitoring circuit, 7 is a 7-segment display control circuit, and 9 is an LED8 control circuit. The CPU monitor circuit 6 monitors the states of the CPUs 0, 4 and 1, 5 and notifies the LED control circuits 9, 7 segment display control circuit 7 of the states of the CPU 0, CPU 1. The LED control circuit that has received the information turns on the corresponding LED 8. In addition, the 7-segment display control circuit 7 converts the data into an element lighting signal according to the selection information of the display selection switch 3 and outputs the 7-segment LED2.
Display on

(Problems to be Solved by the Invention) However, the conventional display system having the above-described configuration has an LED for displaying the CPU status, a stop code for each CPU, a 7-segment LED for displaying the hardware status, and A space for mounting a display selection switch for switching the display is required, but there has been a problem that the space cannot be secured in recent years as the device becomes smaller and more sophisticated.

Further, there is a problem in that the cost is high because the number of parts of the display panel is large.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the problems of the mounting space described above, and to provide a system display method that is economically advantageous without degrading the conventional functions.

(Means for Solving the Problems) The present invention, in a segment type display device having a segment type display device that performs display by combining a plurality of segments, monitors the state of the CPU, and CPU state data indicating the state of the CPU, A CPU monitoring circuit that outputs the CPU stop code that indicates the status immediately before the CPU stops, a switch that switches between the CPU status display and the stop code display, and CPU status data and the CPU stop code are held and the switches are switched. According to the above, the segment type display is provided with a segment display control circuit for displaying either the CPU status display or the stop code display.

(Operation) Each segment of the segment type display according to the present invention,
In addition to the original function of displaying character information in cooperation with other segments, it has a function as an independent indicator light. The function as an independent indicator light is a function of displaying that a certain condition is met or not met, and is a display function performed without cooperating with other segments.

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

FIG. 1 is a drawing showing an example of a display panel according to the present invention. In this figure, 11 indicates a display panel, and 2, 3
Has the same meaning as described above. The display panel shown in FIG. 1 is different in configuration from the conventional display panel (FIG. 2) in the following points. That is, in this embodiment,
The item "CPU status display" is newly added to the display selection switch 3, while the eight LEDs 8 for displaying the status of the CPU, which are present in the conventional display panel, are removed. Then, instead of being removed, a character representing the lighting condition of the LED in the arrangement of the LED 8 in FIG. 2 is written above the 7-segment LED 2. In the display panel of FIG. 1, whether or not the lighting conditions of CPU0 and CPU1 are met is displayed by the segments A and D of the 7-segment LED 2, respectively.

Next, an outline of the operation of the display circuit of the display panel of FIG. 1 will be described with reference to FIG. FIG. 4 is a block diagram of the display circuit of FIG. In this figure, 17 is a 7-segment display control circuit, 17a is a 7-segment display control circuit 17
The control unit 17b is a display unit for lighting the 7-segment LED 2, and 2 to 6 have the meanings described above. The CPU monitor circuit 6 monitors the states of the CPUs 0, 5 and 1 of the CPU 1, and monitors the state 7
The control unit 17a of the segment display control circuit 17 is notified. The control unit 17a sends the information and the data to be displayed according to the selected item of the display selection switch 3 to the display unit 17b, and the 7-segment LED 2 displays the data.

Next, the operation of the display unit 17b will be described with reference to FIG. FIG. 5 shows the display section 17b (7-segment LED1 in FIG. 4).
The circuit diagram of each) is shown. In this figure, 21 is a data holding circuit for the hexadecimal data 26 of the stop code, 22 is 7 segments
Decoder / driver circuit for LED display, 23 is a data holding circuit for CPU status data 28, 30 is a driver circuit for individual display of each segment, 24 is a display selection signal corresponding to the selection mode of the display selection switch 3, 25 is an inverter circuit, 27 is a hexadecimal data write signal, 29 is a CPU status data write signal, 28a is a signal line for segment A lighting, 28d is a signal line for segment D lighting, each of which is a CPU
It is for displaying the CPU status of 0 and CPU1. The data holding circuit 21 is a circuit for holding the hexadecimal data 26 from the control unit 17a, and its output is connected to the decoder / driver circuit 22. The decoder / driver circuit 22 converts this hexadecimal data into the element lighting code of the 7-segment LED 2. Furthermore, the output of the decoder / driver circuit 22 is a 7-segment LE.
It is connected to D2. On the other hand, the output of the holding circuit 23 holding the CPU state data 28 is connected to the signal line a and the signal line d of the 7-segment LED 2 through the driver circuit 30.
In addition, the display selection signal 24 is supplied to the decoder / driver circuit 22.
It is connected to the OE (output enable) terminal and to the OE terminal of the driver circuit 30 via the inverter circuit 25. The OE terminal is a terminal for controlling an output signal. When a logic "0" is input to this terminal, the output becomes a high impedance state and is logically cut off from the outside. When a logic "1" is input to this terminal, the output signal outputs a logic "0" or a logic "1" according to the input signal. In this way, the display selection signal 24 switches between displaying the hexadecimal code on the 7-segment LED 2 and displaying the state of the CPU.

Next, a 7-segment LE on the display panel with the above configuration
The display method of D2 will be described.

First, when either "CPU0 stop code" or "CPU1 stop code" is selected by the display selection switch 3, the control unit 17a reads the information and outputs the hexadecimal data 26 to be displayed based on the information. It is output and written in the data holding circuit 21 by the hexadecimal data write signal 27. This data is further decoded by the decoder / driver circuit 22 into a hexadecimal data display code. At this time, the display selection signal 24
Since the logic "1" is output, the output of the driver circuit 30 is in a high impedance state. Therefore, the output of the decoder / driver circuit 22 becomes valid and the data is displayed on the 7-segment LED 2.

Also, with the display selection switch 3, "CPU status display"
When the display selection signal 24 is selected, the control section 17a outputs a logic "0", and the output of the decoder / driver circuit 22 becomes a high impedance state. On the other hand, the driver circuit 30
Since the OE terminal is connected via the inverter circuit 25, the OE terminal becomes logic "1", and the output of the driver circuit 30 becomes valid. At this time, CPU status data from the control unit 17a
28 is output, which is written in the data holding circuit 23 by the CPU status write signal 29 and displayed on the 7-segment LED 2 through the driver circuit 30. For example, when displaying the state of the CPU0, the CPU 17 writes the data for enabling the signal on the signal line 28a from the control unit 17a to the data holding circuit 23 by the CPU state data write signal 29. Since the output signal of the data holding circuit 23 is connected to the signal line a of the 7-segment LED 2, as shown in FIG.
LED lights up and displays the status of CPU0. Similarly, when displaying the status of CPU1, signal line d of 7-segment LED2
The LED of D in FIG. 6 (2) corresponding to is turned on to display the state of CPU1.

In addition, in the above description, A and D of FIG.
I showed an example of CPU status display using LEDs, but B, C, E, F
Needless to say, it is possible to display any function by combining with each LED of, and to display a multi-function.

Further, in the above-described embodiment, the case where the display panel uses a 7-segment LED has been described as an example. However, the present invention is not limited to this, and the present invention relates to a segment type display device having a plurality of segments. Of course, it can be applied to both.

(Effects of the Invention) As described above in detail, according to the present invention, a segment type display having a plurality of segments is used as a display of character information, and a part of the segments is used as an indicator light alone. Since it is also used, it is possible to reduce the mounting space of the display panel, and since the display element is shared, it is possible to realize lower cost and lower power consumption than the conventional display panel. it can.

[Brief description of the drawings]

1 is a display panel according to the present invention, FIG. 2 is a conventional display panel, FIG. 3 is a block diagram of the display circuit of FIG. 2, and FIG.
1 is a block diagram of the display circuit of FIG. 1, FIG. 5 is a circuit diagram of the display unit 17b of FIG. 4, and FIG. 6 is a circuit diagram (1) and an external view (2) of a 7-segment LED. 2 …… 7 segment LED, 3 …… Display selection switch, 11
...... Display panel.

Claims (1)

(57) [Claims] 1. A segment-type display device having a segment-type display device that displays a combination of a plurality of segments, monitors the state of the CPU, CPU state data indicating the state of the CPU, and a state immediately before the CPU is stopped. A CPU monitoring circuit that outputs a CPU stop code that indicates, a switch that switches between CPU status display and stop code display, CPU status data and a CPU stop code are retained, and a segment-type display is provided according to the switch A segment type display device characterized in that a segment display control circuit for displaying either a CPU status display or a stop code display is provided on the.