JP2002267776A - Electronic timepiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the rewrite of preliminarily written rate adjustment data or the like by the runaway of a microcomputer when detecting a voltage drop and writing time contents, hand position contents or the like. SOLUTION: This electronic timepiece comprises a gate circuit 16 for prohibiting the connection to the rate adjustment data or the like written in a memory means 13 when detecting the voltage drop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electronic timepiece.

[0002]

2. Description of the Related Art Conventionally, a storage means capable of writing and reading data of a hand position and the like is provided. When a voltage drop of a power supply voltage is detected, a pointer position data is written into a nonvolatile memory and a clock operation is stopped. A so-called hand position storage timepiece that reads out the pointer position data from the non-volatile memory and restarts the timekeeping operation has been commercialized. Clocks have also been commercialized in which data for adjusting the rate is written to another address of the above-mentioned nonvolatile memory so that the rate data unique to the clock is not lost. Normally, the rate data is created and written based on the rate measured in the inspection stage of the watch. Such write / read control is all performed by microcomputer software.

[0003]

However, in the above configuration, the pointer position storage operation is required only when the voltage drop is detected, so that the microcomputer runs away no matter how much the voltage detection level is set to the safe side. There is a slight possibility left. Data that can be initialized by software, such as pointer position data, can be set relatively easily even if rewritten by, for example, a microcomputer runaway, but data written before product shipment, such as rate adjustment data, is rewritten. Then, it is necessary to collect the clock and perform the writing operation again on the manufacturer side, which is a major problem. An object of the present invention is to solve the above problems and to protect data such as rate adjustment data that requires a great deal of labor for rewriting.

[0004]

The present invention for achieving the above object has the following configuration. A crystal oscillator that outputs a reference signal, a frequency divider that inputs a signal from the crystal oscillator and outputs a frequency-divided signal, a clock circuit that receives the frequency-divided signal from the frequency divider as an input, and outputs a clock signal, Display means for displaying the timed content of the timekeeping circuit, a voltage detection circuit for measuring the voltage of the power supply, and storing the display content of the display means and data other than the display content when the voltage detection circuit detects a drop in voltage. An electronic timepiece having storage means for performing a write / read control on the storage means, wherein when the voltage detection circuit detects a drop in voltage, the control means displays the content data of the display means. Connection preventing means for preventing connection with other data.

Further, the data other than the display contents is frequency adjustment data of the frequency dividing circuit.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit block diagram of an electronic timepiece according to the present invention. An oscillator 1 uses a crystal oscillator as a reference signal, and outputs an oscillation signal. Reference numeral 2 denotes a frequency dividing circuit which receives an oscillation signal from the oscillator 1 and outputs a frequency-divided signal S2.
At 3, the rate is adjusted. Reference numeral 3 denotes a well-known microcomputer (hereinafter, referred to as a microcomputer).
a, RAM 3b, and ROM 3c. RO
A program for controlling the CPU 3a is written in M3b.
Performs a counting operation of the reference clock frequency division signal S2 while the data exchanged between the AM3c, second hand 11a, the hour and minute hands 11c to be described later in accordance with the clocking time, 11b, the date plate 11
The needle position of d is calculated, and each needle is controlled. It also controls the operation and output signal according to the input signal. The result of calculating the hand position is stored as hand position data in a hand position storage unit 3d in the RAM 3c.

Reference numeral 4 denotes a drive pulse S4 having alternately different polarities.
0, S41, and S42.
A drive pulse selected by the selection signal S30 from the microcomputer 3 is output to drive the step motors 5, 6, and 7.
Reference numerals 8, 9, and 10 denote reduction gear trains meshed with the stepping motors 5, 6, and 7. The minute hand 11b and the hour hand 11c supported by the minute wheel and the hour wheel that constitute a part of the train wheel train 9 and the hour and minute, respectively. Is displayed.

Reference numeral 12 denotes a power supply voltage detection circuit, which samples the power supply voltage by a timing signal S31 from the microcomputer 3, and compensates for the operations of the microcomputer 3, the step motors 5, 6, 7, and the reduction gear trains 8, 9, 10. When the lowest possible voltage is detected, a voltage drop signal S120 is output. Also, the power supply voltage detection circuit 12 has a power supply voltage return circuit inside,
The solar clock emits light, and the general clock outputs a voltage recovery signal S121 when the power supply voltage recovers due to battery replacement or the like.

Reference numeral 13 denotes a storage means constituted by a nonvolatile memory or the like, which performs data writing and data reading of an address designated by an address signal S32, a data input / output signal S33 and a control signal S34 from the microcomputer 3.
Also, the rate adjusting data from the external writing device 14 described later is output to the frequency dividing circuit 2 as the adjusting signal S13. 14
Is an external writing device, which is used when writing data (for example, rate adjustment data) in advance in the storage means 13, and includes an address signal S140 and a data signal S141 for writing.
And outputs the control signal S142. The microcomputer 3 writes data to an address specified in the storage means 13 by an external write only address signal S35, a data input / output signal S33, and a control signal S34 via the gate circuit 16 based on a signal from the external writing device 14. Gate circuit 16
Is a voltage drop signal S output from the power supply voltage detection circuit 12.
At 120, the state is turned off, and the addressing of the storage means 13 is prohibited.

Reference numeral 15 denotes a switch group which operates in conjunction with the external operation member, and is a crown (not shown) of the external operation member.
A switch SWa that operates in conjunction with the one-stage drawer position,
The switch comprises a switch SWb which operates in conjunction with a crown two-stage pull-out position, a switch SWc which operates by rotating the crown in a forward direction, and a switch SWd which operates by rotating the crown in a reverse direction. 3 has been entered. The microcomputer 3 performs a correction operation and the like according to a program written in the ROM 3b in response to a switch input operation signal.

Next, the operation of the electronic timepiece having the above configuration will be described with reference to FIG. The rate adjustment data is written and stored in advance in the storage means 13 in an inspection process or the like according to the following procedure. The external writing device 14 sets the address at which the rate adjustment data is written in the address signal S140, sets the rate adjustment data in the data signal S141, and outputs a write signal as the control signal S142. The gate circuit 16 receives the voltage drop signal S120 from the power supply voltage detection circuit 12, but since a sufficient voltage is supplied from the outside in an inspection process or the like, the voltage drop signal S120 is not output, and the gate circuit 16 is turned on. The state is maintained. The microcomputer 3 is an external writing device 1
4, an address for writing the rate adjustment data is output to the external write only address signal S35 via the gate circuit 16, the rate adjustment data is output to the data input / output signal S33, and the write signal is output to the control signal S34. Then, the rate adjustment data is written and stored in the specified address of the storage means 13.

When the battery is turned on or the like, the entire system is initialized (not shown). The rate adjustment data stored in the storage means 13 is output to the rate adjustment signal S13 immediately after the so-called system reset. Adjust the rate. The wearer sets the reference position by setting the second hand 11a to the 12 o'clock position, the hour and minute hands 11b and 11c to the 12 o'clock position, and the date plate 11d to one day by rotating the crown at the first and second stages. When the reference position is set and the crown is pushed down to the 0th step (normal position), the microcomputer 3 stores that the reference position setting has been completed, and stores the contents of the time measurement at 12:00 am on January 1, 0
At the minute 00 second, the hand position data of the second hand 11a, the hour / minute hands 11c, 11b, and the date plate 11d in the hand position storage unit 3d are set to the initial values, the timekeeping operation is started, and the second hand is moved by one second.
At the same time, the second hand position data in the hand position storage unit 3d is also added.

Next, the operation of adjusting the time and calendar will be described. When the crown two-stage pulling position signal SWb after the reference position setting is completed is input, the microcomputer 3 sets the time correction state, clears the second of the clock content, and stops the clock operation. At the same time, the number of drive pulses from the current hand position data of the second hand 11a to the 0 second position (12 o'clock position) is calculated, and a selection signal S30 corresponding to the number of pulses is output. The second hand 11a is moved to the 0 second position (12 o'clock position) by the drive pulse S40 of the converter drive circuit 4 and stopped. Further, the second hand position data stored in the hand position storage unit 3d is initialized.

By rotating the crown in this state (the crown is pulled out from the second stage), the time is corrected. When the crown rotation operation is input, the microcomputer 3 discriminates between the forward rotation operation and the reverse rotation operation and outputs a selection signal S30. The converter drive circuit 4 outputs a drive pulse S41 for forward rotation in the case of a forward rotation operation and a drive pulse S41 for a reverse rotation in the case of a reverse rotation operation according to the selection signal S30. At the same time, the hand position data in the hand position storage unit 3d is updated. The minute hand 11b and the hour hand 11c are operated by the drive pulse S41 via the stepping motor 6 and the reduction wheel train system 9. The hour and minute of the time measurement, the hour and minute in the hand position storage unit 3d, and the hand position data of the day are also updated at the time corresponding to the current time. When the crown is released from the double-pull position at the exact minute of the time signal, the timing operation starts.

When the crown is pulled out of the two-step pulling position and the crown is pulled down, the calendar correction state is set. Is output. The converter driving circuit 4 uses the selection signal S30 for forward rotation when the forward rotation is performed,
At the time of the reverse rotation operation, a drive pulse S42 for reverse rotation is output.
At the same time, the date of the time is updated, and the hand position data of the date plate in the hand position storage unit 3d is updated. The date plate 11d has a drive pulse S42.
Thus, the motor operates via the step motor 7 and the reduction gear train 9. Crown 1-step pull position is released and normal position (0 step)
When it becomes, the hand starts moving for one second, and becomes the normal use state.

In a normal use state, the microcomputer 3 outputs the frequency-divided signal S2
Is performed, and the hand positions of the second hand 11a, the hour and minute hands 11c, 11b, and the date plate 11d according to the contents of the time measurement are calculated, and each hand is controlled. The result of calculating the hand position updates the hand position data in the hand position storage unit 3d in the RAM 3c. The microcomputer 3 outputs a timing signal S31 when a one-minute carry occurs, and the power supply voltage detection circuit 12
Samples the power supply voltage. Power supply voltage detection circuit 12
When a voltage drop is detected, a voltage drop signal S120 is output. The microcomputer 3 stops the measuring station operation in response to the voltage drop signal S120, and repeats the following procedure for the contents of the time measurement in the RAM 3c, the second hand position data, the hour / minute hand position data, and the date hand position data in the hand position storage unit 3d to store the data in the storage unit 13 Write to. 1. An address signal S3 indicates where to write in the storage means 13.
Specify with 2. 2. The write data is output as the data input / output signal S33. 3. A write signal is output as the control signal S34. On the other hand, since the gate circuit 16 is turned off by the voltage drop signal S120 output from the power supply voltage detection circuit 12, the external write-only address signal S35 designating the address of the storage means 13 writes the data in the storage means 13 in advance. There is no need to select the enclosed area, and much less to rewrite the data. When the writing is completed, the microcomputer 3 is stopped, and waits for the return of the power supply voltage.

When the power supply voltage returns, the power supply voltage detection circuit 12 outputs a voltage return signal S121. The microcomputer 3 starts the operation with the voltage return signal S121, and reads out the timekeeping content, second hand position data, hour / minute hand position data, and date hand position data which are written and stored in the storage means 13 when the power supply voltage drops, by repeating the following procedure. The contents of the time measurement in the RAM 3c and the hand position storage unit 3d are stored. 1. The location stored in the storage means 13 is designated by the address signal S32. 2. The read signal is output as the control signal S34. 3. The data output to the data input / output signal S33 is read. 4. The data is stored in the timekeeping contents of the RAM 3c and the hand position storage unit 3d.
To fit. When the reading is completed, the microcomputer 3 starts a timing operation.
There is no need to set the reference position because the contents of the time and the inside of the hand position match. However, there is a time lag between when the voltage drops and the microcomputer stops and when the voltage returns, so that time adjustment is necessary.

Although the present invention has been described with reference to the adjustment data of the frequency dividing circuit, the present invention can also be used with the rate adjustment data of the oscillation circuit or the serial number.

[0019]

As described above, according to the present invention, when information on the operation, such as the contents of timekeeping and the position of the hand, is written into the storage means when a voltage drop is detected, the information is written in advance as rate adjustment data. Since the address signal and the write control signal are prohibited, especially when the external power is supplied during the manufacturing process and inspection is performed, and the power is removed after completion, sudden voltage may be generated by driving the needle during operation due to the accumulated charge in the capacitor. Even if the microcomputer runs out of control due to the decrease, the address signal and the write control signal are prohibited in a hardware manner, so that an erroneous data can be supplied and an electronic timepiece with a stable quality can be supplied without being rewritten.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of an electronic timepiece according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oscillator 2 Divider circuit 3a CPU 3b ROM 3c RAM 3d Needle position storage unit 12 Power supply voltage detection circuit 13 Storage means 16 Gate circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F001 AA06 AD00 AD01 AE04 AF03 AG16 AH00 AH05 2F002 AA12 AD06 AD07 AE01 BA06 BA08 BD03 CB15 ED01 ED02 ED05 GA04

Claims (2)

[Claims] 1. A crystal oscillator that outputs a reference signal, a frequency divider that inputs a signal from the crystal oscillator and outputs a frequency-divided signal, and outputs a time-counted signal by using a frequency-divided signal from the frequency divider as an input. A time counting circuit, a display means for displaying the time content of the time counting circuit, a voltage detection circuit for measuring a voltage of the power supply, and a display content and a display content of the display means when the voltage detection circuit detects a decrease in voltage. An electronic timepiece having storage means for storing data other than the above, and control means for performing write / read control on the storage means, wherein when the voltage detection circuit detects a decrease in voltage, the control means displays the display. An electronic timepiece provided with connection preventing means for preventing connection with data other than display content data of the means. 2. The data other than the display content is frequency adjustment data of the frequency dividing circuit.
Electronic clock as described.