JPH04361312A - Camera - Google Patents

Abstract

PURPOSE:To eliminate a terminal exclusive for reset connecting a tool in the case of adjustment such as reloading data by executing an initializing processing program when the level of a certain terminal is changed from a certain level to a specified level within prescribed time. CONSTITUTION:A microcomputer 1 is provided to output a specified level signal from the input/output terminal of data in the case of no communication. The microcomputer 1 detects the input state of an input circuit 2 according to an initial state due to the turning-on of a power source, drives an output circuit 3 corresponding to the input state and controls the camera. A terminal group 6 is provided for adjustment or the like in the case of writing a parameter in an EEPROM 5. First of all, the state of a terminal 20 is detected and when the level is high, a device such as the EEPROM 5 is selected through a chip selecting line 10 or the like. Then, the data are inputted and after the data is inputted, the device selection is canceled. On the other hand, when the state of the terminal 20 is not at the high level, a timer is started and initialization is executed after the terminal is turned to the high level.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing device for a microcomputer used in a camera or the like.

0002

2. Description of the Related Art Conventionally, microcomputer control detects the state of a parallel input switch connected to an input port, and performs an action according to a predetermined program depending on the switch state. Further, the reset etc. can be performed by using a similar switch or pressing the same switch for a long time. Furthermore, when adjustments such as rewriting data are made to the microcomputer using a tool in a factory or the like, the tool is connected to the microcomputer to perform the processing. Furthermore, when the microcomputer is reset using this tool, the microcomputer is provided with an input terminal exclusively for reset.

0003

[Problems to be Solved by the Invention] As mentioned above, in the conventional device, there is a problem that a dedicated reset terminal must be added in order to reset using a tool, and the present invention aims to solve this problem. do.

0004

SUMMARY OF THE INVENTION In the present invention, the state of a microcomputer data terminal is determined, and when the data terminal is in a predetermined state, processing such as a reset operation is executed. With this configuration, by connecting the tool to the terminal and transmitting the signal of the predetermined state from the tool to the terminal, processes such as reset operations can be performed without providing a dedicated reset terminal. .

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall view of a camera having a data reading device according to the present invention. 1 is a microcomputer (hereinafter referred to as Mcom) with a one-chip configuration, and internally includes ALU, ROM, RAM, and SEQ.
It has UENCER. The Mcom detects the input state of the input circuit 2 from the initial state when the power is turned on, and controls the camera by driving the output circuit 3 according to the input state. The Mcom has a function of suppressing power consumption by performing hold processing such as switching the clock to a low frequency by itself when there is no change in the input state from the input circuit 2. 4 is a serial input/output circuit, 5 is an EEP as a memory
Indicates ROM. The terminal group 6 is an adjustment terminal group used for monitoring the camera status output to know the camera status and writing parameters to the EEPROM. Data writing processing to the EEPROM is performed at a factory or the like by connecting a tool or the like external to the camera to this group of terminals. 7 is a synchronization clock line for serial input/output,
8 is the serial input line seen from the μcom side, 9 is the μcom
The serial output line seen from the side, 10 is a chip select line for selecting the EEPROM, and 11 is a chip select line for selecting the serial input/output circuit 4. FIG. 2 is an internal diagram of the serial input/output terminal of μcom1. μcom
1 is pulled up to high level by a pull-up resistor 21 as shown in the figure in order to input/output the series input/output terminal 30 in parallel and to protect the input terminal when it is open. 22 is an input buffer, and 24 is an output buffer that can be output by a signal to line 23.

Next, the operation will be explained using FIGS. 3 and 4.

The flow of FIG. 3 shows a serial input program. In this program, first, in step 1, the state of the terminal 20 is detected. When the state of this terminal 20 is high, the EEPROM is selected via the chip select line in step 2.
Select the 5th grade device. Next, in step 3, the data of the selected device is input, and after inputting the data, the device selection is canceled in step 4, and the process returns. On the other hand, if the state of the terminal 20 is not high when step 1 is executed, the flow of FIG. 4 is executed. In the flow of FIG. 4, the timer is started in step 5, the state of the above-mentioned terminal is determined in step 6, and if the terminal is not high, it is determined in step 7 whether or not the timer time has elapsed, and the timer time has elapsed. If not, return to step 6. If the terminal becomes high within this timer time, the initialization program is executed in steps 8 and 9.

On the other hand, if the terminal does not become high even after the timer time elapses, a sleep program is executed in steps 10 and 11.

As described above, the terminal 20 is pulled up and is therefore high, and if this terminal is not high, a terminal abnormality such as a short circuit will occur. Therefore, when the terminal is high in the input program shown in FIG. 3, normal data input processing is performed. On the other hand, when a terminal is abnormal, a sleep process is performed in the process shown in FIG. This sleep processing suspends all activities.

On the other hand, if the terminal returns to high within a predetermined time, it is determined that artificial processing has been performed, and the initial program is executed.

Therefore, for example, using a tool, EEPROM
When the data is rewritten, the initialization program is executed by forcing the terminal to be low for a predetermined period of time using a tool. This initialization program performs operation processing for causing μcom1 to read the rewritten data.

FIG. 5 is a flowchart showing an example in which the present invention is applied to a data output program. In this flow, the same as the input program in Figure 3, the terminal is checked before data output processing, and similarly to the input program above, when an abnormality in the terminal status is detected, processing different from the data output processing is performed. It is what is done.

[0013]

[Effects of the Invention] As described above, when a terminal check is performed during data input/output processing, and an abnormality in the terminal is detected as a result of the check, it is possible to proceed to a predetermined processing. Initialization processing and the like can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a camera according to the present invention.

FIG. 2 is a circuit diagram showing the internal configuration of an input terminal of the microcomputer shown in FIG. 1;

FIG. 3 is an explanatory diagram showing a flowchart for explaining the operation of the present invention.

FIG. 4 is an explanatory diagram showing a flowchart for explaining the operation of the present invention together with FIG. 3;

FIG. 5 is an explanatory diagram showing a flowchart for explaining another example of operation of the present invention.

[Explanation of symbols]

1. Microcomputer 5 EEPROM

Claims (1)

[Claims] 1. A camera equipped with a computer that outputs a specific level signal from a data input/output terminal when not communicating, detects the level of the terminal and outputs the level when communicating with a device connected to the terminal. but,
Providing a determination means for determining whether or not a level other than the specific level has transitioned to the specific level within a predetermined time,
A camera characterized in that when the determination means determines that the level has transitioned from a level other than the specific level to the specific level within a predetermined time, an initialization processing program is executed.