JPH06342088A - Timing system, semiconductor device, timing device - Google Patents

Abstract

(57) [Abstract] [Purpose] When clocking with a crystal oscillator, the purpose is to perform temperature correction of the oscillation frequency with high accuracy. [Structure] A crystal oscillation circuit, a frequency dividing stage, a 1 Hz timer interrupt circuit, a temperature measurement circuit, temperature characteristic data of crystal oscillation frequency deviation, and time measurement data. The oscillation is caused by temperature fluctuations at each time measurement. It has a means for correcting the delay of the frequency into timekeeping data. [Effect] With an inexpensive and small-sized device, the temperature of the time-measurement data can be corrected in real time with high accuracy in the ppm order and a highly accurate time-measurement device can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to highly accurately correct the temperature of a CPU type clock, a real time clock or the like. Normally, the timekeeping data processed by the CPU software is based on a signal obtained by dividing the crystal oscillation frequency of the original oscillation by the frequency dividing circuit, and to the timekeeping data buffer on the memory managed by the CPU for each cycle, The minimum unit of timekeeping data is added. For example, the last stage of the frequency divider is 1
In the case of a Hz signal, 1 Hz generated from that 1 Hz signal
The CPU recognizes the timer interrupt signal, and every time the 1 Hz timer interrupt occurs, 1 is added to the 1-second digit of the clock data buffer. However, the crystal oscillator and the oscillation circuit
Since it has an oscillation frequency temperature characteristic, it is necessary to correct the time measurement data by the oscillation frequency temperature characteristic in order to perform highly accurate time measurement. In the present invention, in a cycle in which the minimum unit of time measurement data is added, temperature measurement is performed by a single or a plurality of temperature sensors and a temperature measurement circuit, and the temperature characteristic data of the oscillation frequency deviation of the crystal oscillator corresponding to the measured temperature, A temperature-corrected timekeeping means characterized by reading out from the memory or calculating by calculation, calculating a timekeeping data correction value from the temperature characteristic data of the oscillation frequency deviation, and adding the timekeeping data correction value to the timekeeping data buffer, as well as,
The present invention relates to a semiconductor device having a temperature sensor and a crystal oscillator as external components and a time measuring device for realizing the temperature-corrected time measuring means.

[0002]

2. Description of the Related Art As a temperature correction method for timekeeping in a conventional timekeeping device, based on a result of temperature measurement, the original oscillation of a crystal oscillator is adjusted by means such as capacitance adjustment, or a programmable frequency divider is used. A method according to whether or not adjustment is performed at the frequency dividing stage of the original vibration by means of frequency division ratio adjustment, temperature correction additional pulse insertion, or the like has been used.

[0003]

However, in the prior art,
There are the following problems. In the method of adjusting the crystal oscillation of the crystal oscillator by means such as capacitance grading, it is necessary to finely adjust the capacitance in the oscillation circuit to correct the oscillation frequency error for each temperature.Pulse duty control or multiple parallel coupling capacitance A complicated hardware configuration such as switching control is required, and there remains a problem such as adjustment for variations in the characteristics of each capacitive element component. Therefore, in the conventional technique for adjusting the original vibration of the crystal oscillator by means such as capacitance grading, there is a problem that a highly accurate timekeeping device cannot be realized at low cost.

Further, in the method of adjusting in the frequency dividing stage, the correction accuracy is limited because the minimum unit of correction cannot be less than the original vibration frequency in both the frequency division ratio adjusting means and the correction pulse inserting means. For example, the crystal oscillation frequency is 32.768KH
In the case of z, the minimum unit that can be adjusted by the frequency divider is 30.5
When the correction is performed in a cycle of 1 second, the minimum unit of correction accuracy is 30.5 μsec / 1 sec = 30.5p.
Since it becomes pm, it is not possible to obtain sufficient correction accuracy for realizing an annual difference clock or the like. In addition, although the apparent correction accuracy is improved by lengthening the correction cycle, since the method is assumed to have no temperature change during one cycle, the actual accuracy is improved each time a temperature change occurs. Will get worse. For example, if the correction cycle is 100 seconds, the minimum unit of correction accuracy is 3
Although 0.5 μsec / 100 sec = 0.305 ppm, the temperature is assumed to be constant for 100 seconds, which is not realistic when the usage environment of a timekeeping device such as a general clock or real-time clock is assumed. Therefore, the conventional method of adjusting in the frequency dividing stage has a problem in that it is not possible to perform temperature correction of time measurement with sufficiently high accuracy.

Therefore, the present invention solves such a problem by measuring the temperature at an appropriate cycle in consideration of the environment of use of the timing device, calling the memory for each temperature measurement, or
An object of the present invention is to provide a means, a semiconductor device, and a timing device for realizing highly accurate temperature-corrected time counting by adding highly accurate temperature-corrected data of oscillation frequency by calculation to uncorrected time-measurement data. To do.

[0006]

The clocking method of the present invention comprises: a) a crystal oscillator, an oscillation frequency adjusting capacitor and a crystal oscillation circuit; b) a temperature sensor and a temperature measuring circuit; and c) the crystal oscillation circuit. A frequency dividing circuit for converting the signal of 1 to a clock signal; d) a storage device containing temperature characteristic data of the oscillation frequency deviation of the crystal oscillator; and e) the temperature measuring circuit for each time the clock signal is generated. Means for performing temperature measurement; and f) after the temperature measurement, a multiplication operation of an oscillation frequency deviation corresponding to the measured temperature read from the storage device and a clock signal period at room temperature output from the frequency dividing circuit is performed. ,
Means for obtaining a temperature correction value for the timekeeping signal cycle; and g) adding the temperature measurement value for the room temperature time and the temperature correction value for the timekeeping signal to the timekeeping value after obtaining the temperature correction value for the timekeeping signal cycle. And means for performing.

Further, the semiconductor device of the present invention comprises: a) a crystal oscillator, a crystal oscillation circuit requiring an oscillation frequency adjusting capacitor as an external component, and b) a temperature measurement requiring a temperature sensor as an external component. A circuit, c) a frequency dividing circuit for converting a signal from the crystal oscillation circuit into a clock signal, d) a storage device containing temperature characteristic data of an oscillation frequency deviation of the external crystal oscillator, and e) the time measurement. Means for performing temperature measurement by the temperature measurement circuit each time a signal is generated, and f) an oscillation frequency deviation corresponding to the measured temperature read from the storage device after the temperature measurement, and output from the frequency division circuit. Performs a multiplication operation with the clock signal period at room temperature,
Means for obtaining a temperature correction value for the timekeeping signal cycle; and g) adding the temperature measurement value for the room temperature time and the temperature correction value for the timekeeping signal to the timekeeping value after obtaining the temperature correction value for the timekeeping signal cycle. And means for performing.

The clocking method of the present invention comprises: a) a crystal oscillator, an oscillation frequency adjusting capacitor and a crystal oscillating circuit, b) a temperature sensor and a temperature measuring circuit, and c) a signal from the crystal oscillating circuit. A frequency dividing circuit for converting into a signal, d) means for calculating temperature characteristic data of oscillation frequency deviation of the crystal oscillator, and e) temperature measurement by the temperature measuring circuit each time the clock signal is generated. Means for performing: f) After the temperature measurement, the oscillation frequency deviation corresponding to the measured temperature calculated by the calculation is multiplied by the clock signal period at room temperature output from the frequency dividing circuit, and the clock signal period is calculated. G) means for calculating the temperature correction value of the timekeeping signal cycle, and then, for obtaining the temperature correction value of the timekeeping signal cycle, adding the temperature measurement value of the room temperature time and the temperature correction value of the timekeeping signal to the timekeeping value. When, It is characterized by having.

The semiconductor device of the present invention includes: a) a crystal oscillator, a crystal oscillation circuit requiring an oscillation frequency adjusting capacitor as an external component, and b) a temperature measurement requiring a temperature sensor as an external component. A circuit, c) a frequency dividing circuit for converting a signal from the crystal oscillation circuit into a clock signal, d) means for calculating temperature characteristic data of an oscillation frequency deviation of the external crystal oscillator, and e) the above Means for performing temperature measurement by the temperature measurement circuit each time a clock signal is generated, and f) an oscillation frequency deviation corresponding to the measured temperature calculated by the calculation after the temperature measurement, and output from the frequency dividing circuit. A means for performing a multiplication calculation with the timekeeping signal cycle at room temperature to obtain a temperature correction value for the timekeeping signal cycle; and g) obtaining the temperature correction value for the timekeeping signal cycle, and then calculating the temperature correction value for the room temperature Means for adding the temperature correction value of the timekeeping signal to the timekeeping value.

The clocking system of the present invention comprises: a) a crystal oscillator, an oscillation frequency adjusting capacitor and a crystal oscillation circuit; and b) a plurality of temperature sensors having different operating temperature ranges and a plurality of temperature measuring circuits corresponding to the temperature sensors. And c) a frequency dividing circuit for converting a signal from the crystal oscillation circuit into a clock signal, and d) a storage device containing temperature characteristic data of an oscillation frequency deviation of the crystal oscillator, or an oscillation frequency of the crystal oscillator. Means for calculating temperature characteristic data of deviation by calculation, and e) the most accurate temperature from a plurality of temperature sensors having different operating temperature ranges and a plurality of temperature measuring circuits corresponding to the temperature sensors each time the clock signal is generated. Means for performing temperature measurement by selecting a measured value; f) an oscillation frequency deviation corresponding to the measured temperature read from the storage device after the temperature measurement, and output from the frequency dividing circuit. Performs multiplication operations of a timer signal period at the normal temperature,
Means for obtaining a temperature correction value for the timekeeping signal cycle; and g) adding the temperature measurement value for the room temperature time and the temperature correction value for the timekeeping signal to the timekeeping value after obtaining the temperature correction value for the timekeeping signal cycle. And means for performing.

The semiconductor device of the present invention further comprises: a) a crystal oscillator, a crystal oscillator circuit requiring an oscillation frequency adjusting capacitor as an external component, and b) a plurality of temperature sensors having different operating temperature ranges. A plurality of temperature measuring circuits corresponding to each required as parts, c) a frequency dividing circuit for converting a signal from the crystal oscillation circuit into a clock signal, and d) temperature characteristic data of oscillation frequency deviation of the crystal oscillator. Or a means for calculating temperature characteristic data of the oscillation frequency deviation of the crystal oscillator by calculation, and e) a plurality of temperature sensors each having a different operating temperature range each time the clock signal is generated. Means for performing the temperature measurement by selecting the most accurate temperature measurement value from the plurality of temperature measurement circuits corresponding to, f) the measured temperature read from the storage device after the temperature measurement. And respond to an oscillation frequency deviation performs multiplication operation between clocking signal period at the normal temperature output from said divider,
Means for obtaining a temperature correction value for the timekeeping signal cycle; and g) adding the temperature measurement value for the room temperature time and the temperature correction value for the timekeeping signal to the timekeeping value after obtaining the temperature correction value for the timekeeping signal cycle. And means for performing.

The timer device of the present invention comprises: a) the above semiconductor device, b) a crystal oscillator and a capacitor for adjusting the oscillation frequency, c) a plurality of temperature sensors having different operating temperature ranges, and d) an operating device. It is characterized by comprising an input device, e) a display device and an output device for displaying a time value, and f) using the above-mentioned time-counting method.

[0013]

The function of the present invention will be described. The crystal oscillation frequency of the original vibration is f, the period in which the minimum unit of time measurement data is added to the time measurement data buffer by the CPU is τ ₀ , the measured temperature when the time measurement data is added is T, and the oscillation frequency deviation at that temperature is Δf (T ) / F, the time data correction value Δτ is (−τ ₀ × Δf (T) / f). Therefore, the corrected time data τ added to the time data buffer is τ ₀
+ Δτ = τ ₀ (1-Δf (T) / f)
Highly accurate temperature-corrected time measurement can be performed by measuring the temperature at each time data addition cycle or at a cycle that is an integral multiple of the time data and in which the temperature change can be ignored in consideration of the use environment.

[0014]

The details of the present invention will be described below with reference to illustrated embodiments.

FIG. 1 is a block diagram of a digital timepiece having a one-sensor type temperature correction timekeeping function under microcomputer control, which is an embodiment of the present invention.

FIG. 2 is a block diagram of a digital timepiece having a two-sensor type temperature correction timekeeping function under microcomputer control, which is an embodiment of the present invention.

FIG. 3 shows a control flowchart of the temperature correction timekeeping function for obtaining the crystal oscillation frequency deviation from the temperature by converting the data table.

FIG. 4 shows a control flowchart of the temperature correction timekeeping function for obtaining the crystal oscillation frequency deviation from the temperature by square calculation.

FIG. 5 shows a control flowchart of the temperature correction timekeeping function by the two-sensor system for low temperature and high temperature.

FIG. 6 shows a graph of temperature characteristics of crystal oscillation frequency accuracy.

FIG. 7 shows a configuration diagram of time measurement data on the data RAM.

FIG. 8 shows a graph of resistance-temperature characteristics of the temperature sensor (thermistor).

First, FIG. 1 will be described. For basic timekeeping functions, refer to the digital clock microcomputer (1
00) 32.768K generated by the crystal oscillator circuit (160) built in the LSI, the external crystal oscillator (161) and the external capacitor C0 (162) for adjusting the oscillation frequency
The original vibration of Hz is generated. By adjusting the external capacitor C0 (162) for adjusting the oscillation frequency, it is possible to eliminate variations in the component characteristics of the external crystal oscillator (161) and the built-in crystal oscillation circuit (160). The signal obtained by dividing the original vibration by the dividing stage (170)
A timer interrupt generation circuit (17) that generates a minimum unit time τ ₀ of time data that is low enough to be processed by (110)
2) Timer 0 (171) is supplied. CPU is the period τ
_Whenever an interrupt of ₀ occurs, the program stored in the ROM (120) performs temperature measurement, calculation of the temperature correction value of the timekeeping data, and addition processing to the integrated timekeeping data.
The data is stored as high-precision clock data in the clock data buffer mapped on M (130). However, in the case of temperature measurement and calculation of the temperature correction value of the timekeeping data, in consideration of the rate of temperature change in the operating environment, if the temperature change is mild, it is measured once at an integer multiple of the interrupt cycle τ ₀ . To calculate the temperature correction as the average temperature during that period,
It is also possible to program in the ROM (120). For temperature measurement, the built-in timer 1 (181), CR oscillation counter 1 (182), CR oscillation circuit 1 (183),
And a thermistor (18 which is an external temperature sensor)
4), capacitor C (185), reference resistance 1 (186)
Is used. Temperature measurement circuit 1 (1
80) and the measured temperature obtained from the external parts,
The temperature characteristic of the oscillation frequency of the crystal oscillator (161) is corrected. The correction is performed by the conversion data or the conversion calculation program in the ROM (120) set in advance. Also, regarding the built-in crystal oscillation circuit (160), although it is possible to suppress the crystal oscillation oscillation frequency deviation due to the operating voltage characteristic to some extent by the built-in constant voltage circuit, etc. Shows the temperature characteristics of the crystal oscillator (161) and the crystal oscillation circuit (16
The conversion data or conversion calculation program for temperature correction to which the temperature characteristic of 0) is added can be set in the ROM (120). RA corrected for temperature in near real time
The high-precision clock data on the M (130) is sent to the external LCD panel (15) via the built-in LCD driver (150).
It is displayed as time and date data in 1). Further, it is communicated to another device via the I / O (140) as a time data output (141) for a real time clock. Further, the external input device SW (142) is an I / O
It is taken into the microcomputer via the and is used for clock data correction, mode change processing, and the like.

Next, a method of measuring the temperature and a method of controlling the temperature correction of the time measurement data by converting the table data will be described with reference to FIGS. 1 and 3. In FIG. 3, when the timer 0 interrupt INT, τ ₀ (300) processing is started, first, the temperature measurement processing is performed. The CR oscillation circuit 1 (183) in the temperature measurement circuit 1 (180) is turned on (310), and the timer 1 (18)
Set the initial value to 1). Immediately after starting (311) timer 1 (181), CR oscillation frequency counter 1
Counts up (182) (312) and timer 1
It continuously counts up and waits until (181) overflows (313). Immediately after the timer 1 (181) overflows, the CR oscillation frequency counter 1 (18
2) is stopped (314), and the CR oscillation count value is obtained by the external thermistor 1 (184) and the capacitor C1 (185) within a fixed time.

Here, in order to set a fixed time in the timer 1 (181), the CR oscillation frequency counter 1 (182)
A constant count value initialized to: CNTinit overflows CR with reference resistor 1 (186): R1ref and capacitor C1 (185): C1 until overflow, and the time is counted down by timer 1 (181). The initial value: tinit is set by the measuring method. in this case,
Reference resistance 1 (186): R1ref and capacitor C1 (1
85): CR oscillation frequency with C1: fC1-R1ref is expressed by the following equation.

FC1-R1ref = K / (C1 × R1ref) (1800) where K is an oscillation coefficient peculiar to the CR oscillation circuit. The relationship between the initial value of the timer 1 (181): tinit and the initial value of the CR oscillation frequency counter 1 (182): CNTinit is given by the following equation.

Tinit = CNTinit / fC1-R1ref (1801) Substituting the equation (1800) into the equation, tinit = CNTinit × (C1 × R1ref) / K (1802)

After that, the thermistor 1 (184): R1th
er and the capacitor C1 (185): C1 starts CR oscillation, and the timer 1 (181) overflows from the initial value of the timer 1 (181) obtained earlier: tinit. Time to CR
Count up the oscillation frequency counter 1 (182) (3
12) Then, the method of obtaining the count value: CNTther is used. In this case, the CR oscillation frequency of the thermistor 1 (184): R1ther and the capacitor C1 (185): C1: f
C1-R1ther is represented by the following formula.

FC1-R1ther = K / (C1 × R1ther) (1803) Further, the count value: CNTther is the initial value of the timer 1 (181): tinit and the CR oscillation frequency: fC1-R1ref.
It is given by the following formula.

CNTther = tinit × fC1-R1ref (1804) Substituting the equations (1802) and (1803) into this, CNTther = {CNTinit × (C1 × R1ref) / K} × {K / (C1 × R1ther)} = CNTinit × R1ref / R1ther (1805), and the CR oscillation coefficient: K and the external capacitor: C1 having individual component variations are erased, and the thermistor 1
The resistance value R1ther of (184) is obtained from the count value of the CR oscillation frequency counter 1 (182): CNTther, the initial value: CNTinit, and the resistance value R1ref of the reference resistance 1 (186). From the equation (1805), R1ther = R1ref × CNTinit / CNTther (1806) By this method, the variation in the component characteristics of the temperature measuring circuit 1 (180) and the capacitor 1 (185) can be calculated from the temperature measuring means. Can be removed. Therefore, if only the characteristics of the reference resistor 1 (186) are combined, the thermistor 1
The improvement in accuracy of (184) leads to an improvement in accuracy of temperature measurement. After the temperature measurement is completed, the CR oscillation circuit 1 (183) is turned off to save power.

Count value obtained here: CNTther
Is converted into temperature data (T) according to a conversion table prepared in advance in the ROM (120) (32
0). This conversion table data can be created from the equation (1806) and the resistance temperature characteristic data of the thermistor 1 (184). Further, according to another conversion table, the crystal oscillation frequency deviation (Δf (T) / f) from the measured temperature
(330). Generally, the frequency temperature characteristic of a crystal oscillator has a negative quadratic function characteristic as shown in FIG. 6, but there is also a cubic function characteristic depending on the type of the crystal oscillator. In addition, there are cases where the frequency-temperature characteristic of the oscillation circuit cannot be ignored. In the case of frequency-temperature characteristics that cannot be approximated by such a simple calculation, the conversion table method prepared in advance in the ROM (120) is advantageous for the correction processing. Further, when the intermediate measured temperature data is unnecessary, the counter value: CNTther can be directly converted into the crystal oscillation frequency deviation. Crystal oscillation frequency deviation (Δf (T) /
f) and the negative value of the integration calculation result of the timer 0 interrupt period (τ ₀ ) are the correction value Δτ of the timer 0 interrupt period.
Calculate as (T).

[Delta] [tau] =-[tau] ₀ * [Delta] f (T) / f (3400) The timer 0 interrupts the previous time value (tpre (T)) saved in the time data buffer on the RAM (130). Period (τ ₀ ) and timer 0 interrupt period correction value Δτ
A new temperature-corrected time value (tnew (T)) is obtained by adding and calculating (T). tnew (T) = tpre (T) + τ ₀ + Δτ (T) (3500) With the above, the timer 0 interrupt subroutine is completed (3
60).

Substituting equation (3400) into equation (3500) yields:

Tnew (T) = tpre (T) + τ ₀ (1-Δf (T) / f) (3501) where τ ₀ (1-Δf (T) / f) is temperature-corrected. It means the interrupt cycle τ (T) of timer 0.

Τ (T) = τ ₀ (1-Δf (T) / f) (3502) In this control flow, the temperature is measured every timer 0 interrupt period (τ ₀ ). However, if the temperature change is mild considering the usage environment, in order to save power, set the period in which the temperature is assumed to be almost constant as an integer multiple of the timer 0 interrupt period (τ ₀ ), and set that period. Temperature measurement only once in
Treat as. In that case, the correction calculation is also performed only once, and the calculation result τ ₀ (1−Δf (Taverage) / f) is the interrupt cycle τ (Taverage) of the temperature-corrected timer 0 for that period.
Is stored in the RAM (130) as and is used as a constant for timekeeping calculation.

Tnew (T) = tpre (T) + τ (Taverage) (3503) For example, in the case of a general timepiece, the minimum unit of time measurement data is often 1 second. In that case, the timer 0 interrupt period τ ₀ = 1 Hz, and the integration calculation of the equation (3400) can be omitted. That is, Δτ (T) = − Δf (T) / f. If the temperature change of the environment in which the watch is used is gentle, for example, if the error can be ignored even if the temperature is considered to be constant for 10 seconds, temperature measurement and correction calculation are performed at 10-second intervals, and the result is saved in memory for 10 seconds. It is used as a time data correction constant. By doing so, the operating duty of temperature measurement and correction calculation processing can be reduced to 1/10,
You can save power. Whether the temperature measurement cycle is set to 1 second intervals, 10 second intervals, or 30 second intervals depends on the environment in which the timing device is used. However,
Generally, in the temperature measurement by CR oscillation of the thermistor used in the present invention, it takes about 0.5 seconds or more,
The temperature measurement cycle is 1 because accurate temperature measurement cannot be performed.
More than a second. In addition, since the minimum value of the temperature measurement period is 1 second with respect to the temperature change of the usage environment of the timing device, practical problems do not occur in most cases.

An example of temperature characteristics of crystal oscillation frequency accuracy is shown in FIG.
Described in. The horizontal axis represents temperature (610), the vertical axis represents frequency accuracy Δf / f (600), and there is a peak of frequency accuracy Δf / f = 0 at T = 25 ° C. (620). T = 25 ° C
Even if the temperature rises or falls from the peak of, the oscillation frequency becomes slower in proportion to the quadratic function of temperature (6
30). Therefore, the frequency accuracy Δf / f (230) can be expressed by the following mathematical formula.

Δf (T) / f = −a (T-25) ² (6000) Temperature (T) in FIG. 3 / Crystal oscillation frequency deviation (Δf (T) /
Instead of the data table conversion (330) of f), a method of executing the operation of the above formula is also possible. With reference to the block diagram of the digital timepiece shown in FIG. 1 and the flowchart shown in FIG. 4, the temperature correction control when the crystal oscillation frequency deviation is obtained from the measured temperature by the square operation will be described. The block diagram of the digital timepiece and the microcomputer (100) in FIG. 1 is exactly the same as the case of the data table conversion. The difference is the temperature (T) built in the ROM (120).
/ Crystal oscillation frequency deviation (Δf (T) / f) conversion program only. In the flowchart of FIG. 4, the interrupt period tau ₀ Timer 0 interrupt routine (400) to a temperature measurement (410 to 420) are equal, squaring the difference between the measured temperature (T) and standard temperature (T _O) Processing for obtaining the crystal oscillation frequency deviation (Δf (T) / f) by (43
0) is different. The subsequent processing (450) for calculating the temperature-corrected time value is exactly the same.

Comparing the data table method and the operation method in the conversion of the temperature / crystal oscillation frequency deviation, the data table conversion method has an advantage that the conversion processing execution time is short. Further, there is an advantage that a crystal oscillator whose temperature / crystal oscillation frequency deviation is not proportional to a quadratic function can be easily dealt with only by changing the contents of the data table. However,
Since a large ROM capacity is required and the number of pieces of data making up the data table is also restricted by the ROM capacity, there is a temperature pitch interval in the data table and a quantization error occurs. In particular, in the high temperature region or the low temperature region around T = 25 ° C., the degree of influence of the quantization error becomes large.

On the other hand, the crystal oscillation frequency deviation (Δ
The method of obtaining f (T) / f) has the disadvantage that the square operation execution time for conversion is slower than the data table conversion, but it can be realized with a small ROM capacity, and the quantization error is basically Does not exist.

Next, the structure of the clock data on the data RAM of FIG. 7 will be described. The data stored in the RAM (130) of FIG. 1 has the same configuration in both the table data conversion system of FIG. 3 and the arithmetic system of FIG.
First, the 16-bit binary counter data on the CR oscillation frequency counter 1 (182) in the temperature measurement circuit 1 (180) is converted into the measured temperature data (710) of 4 digits of BCD up to the minimum 1/100 ° C. unit. According to the table data conversion method of FIG. 3 or the operation method of FIG.
Convert to a crystal oscillation frequency deviation (720) of 4 digits of BCD up to the unit of 1/100 ppm.

For example, when the measured temperature T = 30.00 ° C. (7100) and the crystal oscillator temperature characteristic is as follows, Δf (T) / f = −a (T-25) ² (7200) a = 0.033 (7201) When the crystal oscillation frequency deviation Δf (T) / f is calculated, the following is obtained.

Δf (30.00) /f=−0.033× (30.00−25) ² = −0.82 5 (7202) Here, the crystal oscillation frequency deviation (720) is 1 / 100
Since the BCD is a 4-digit memory up to the ppm unit, the value rounded off and actually stored in the memory is Δf (30.00) /f=−0.83 (7203).

Further, the temperature correction value (730) of the BCD 9-digit time-interrupt period of the minimum 0.01 μsec unit is obtained by the integration calculation with the time-interrupt period τ ₀ .

In the case of τ ₀ = 1 [sec] (7300), the integration calculation is substantially omitted.

Δτ (30.00) = − τ ₀ × Δf (30.00) / f = −1 × (−0.83) = 0.83 [μsec] = 0.0000803 [sec] ... ( 7301) The time value data that is updated each time a time interrupt occurs (740) is BCD 4-digit year data, BCD 2-digit month data, BCD 2-digit day data, BCD 2-digit hour data,
BCD 2-digit minute data, BCD 2-digit second data, BCD
It is composed of a total of 22 digit BCD data consisting of 8 digit temperature correction data. This timekeeping data contains the timekeeping interrupt period (7
50) is added to the temperature correction value of the clock interrupt period to obtain the temperature-corrected clock value (770).

[0047] The time value before the update (740) and the new time value after the update (770) have the same data structure and are stored in the RAM at the same address in a form of being overwritten. The data of the second time value (770) of this updated new time value (770) excluding the temperature correction portion is transferred to the display buffer as the digital clock display data (780) and processed for display.

1993 01 01 00 00 00 (7800) Here, rounding processing is not performed, and a new time value (7
Only the display part of 70) is transferred, and the data itself is
Up to 8 digits after the decimal point are saved in the memory, and a new timing interrupt period and its correction value are added when the next timing value is updated.

Regarding the accuracy, the measurement temperature accuracy (700,
710), the crystal oscillator temperature characteristic accuracy (720), and the temperature correction value accuracy (730) of the clock interrupt period must be taken into consideration.

Regarding the measurement temperature accuracy (700, 710), the thermistor itself is ± if the operating temperature range is limited.
It is commercially available up to 0.03 ° C. Further, as a method of measuring temperature in a wide temperature range with high accuracy, there is a method of using a plurality of thermistors having different characteristics together. The error factors in the temperature measuring circuit include the CR oscillation frequency, the number of bits of the CR oscillation frequency counter, and the time required for temperature measurement. Therefore, the measurement temperature accuracy varies depending on the measurement temperature range, the thermistor used, the temperature measurement circuit size allowed by price restrictions, the temperature measurement time allowed by current consumption restrictions, etc. About 0.0 ℃ to ± 0.05 ℃
It is measurable.

Regarding the crystal oscillator temperature characteristic accuracy (720), the crystal oscillator component variations, the deviation of the actual characteristic from the arithmetic expression, the quantization error due to the table data conversion, the bit number restriction of the arithmetic and storage memory, the arithmetic time. There are restrictions and error factors such as the temperature characteristics of the crystal oscillation circuit. The variation in the parts of the crystal oscillator can be removed by the initial adjustment such as trimmer capacitor adjustment at the oscillation frequency at room temperature, and the part in the temperature characteristics is small enough to be ignored. Quantization error due to table data conversion, calculation and bit number restriction of storage memory, memory of the microcomputer (ROM, RAM)
Depends on how much can be used. The calculation time in the case of the calculation method is 32.76 in the case of the BCD 4-digit square calculation (720) and the BCD 9-digit addition calculation (760) in the above example.
Microcomputer operating at 8KHz, 100m
It can be completed in about sec. Temperature measurement time 500msec
Since the arithmetic processing and the temperature measurement can be performed in parallel in a sufficiently short time as compared with about 1 sec, the arithmetic processing time is often not a limitation in many cases.

The temperature characteristic of the crystal oscillation circuit can be calculated by performing a linear function approximation and combining them into a single arithmetic expression in which the temperature characteristic arithmetic expression of the crystal oscillator is added to the quadratic or cubic function. Further, if table data conversion in which the temperature characteristics of the crystal oscillator circuit and the crystal oscillator are added is used, they can be combined into one table data conversion. As mentioned above,
Although the crystal oscillation temperature characteristic accuracy depends on the restrictions on the scale of use of the memory, theoretically it can approach zero as much as possible.

Regarding the temperature correction value calculation accuracy (730) of the time counting interrupt period, the calculation scale is small, and the error here is considered to be zero. In the above calculation example (730), integration of 2 digits of BCD and 4 digits of BCD and shift of the decimal point position by 6 digits to the left are only performed.

From the above, the crystal oscillator temperature characteristic accuracy and the temperature correction value calculation accuracy are sufficiently higher than the temperature measurement accuracy, and can be ignored. Therefore, the overall timing accuracy is almost determined by the temperature measurement accuracy.

Next, a digital timepiece having a two-sensor type temperature correction timekeeping function under microcomputer control shown in the block diagram of FIG. 2 and the flowchart of FIG. 5 will be described. The difference between the block diagram of the one-sensor system of FIG. 1 and the block diagram of the two-sensor system of FIG. 2 is (1)
Temperature measurement circuit 2 (290), thermistor 2 (294),
C2 (295) and reference resistance 2 (296) are added, and (2) the thermistor 1 and thermistor 2 have sensors with high-precision characteristics within a limited range for high temperature and low temperature, respectively. It is used and (3) ROM (22
As shown in the flowchart of FIG. 5, the control program incorporated in 0) performs the temperature correction process of the measured value after selecting the thermistor that can measure the temperature with higher accuracy during the temperature measurement. .

The temperature measuring circuit 2 (290) added is
It has the same configuration as the temperature measurement circuit 1 (280),
CR oscillation circuit 2 (293), CR oscillation frequency counter 2
(292) and timer 2 (291). Figure 1
The thermistor (184) for the one-sensor system of
Since it is necessary for the sensor to cover the entire measurement temperature range, it is unavoidable to use a thermistor that has a characteristic that some degree of accuracy can be obtained even in both low temperature and high temperature regions. Figure 8
A graph of temperature characteristics of the thermistor resistance value is shown in FIG. Horizontal axis is temperature (810), vertical axis is thermistor resistance (800)
Is. Measurement temperature range (850) from -40 ℃ to +70
When the temperature is set to ° C, the thermistor B (830) is used as an example in the case of the one-sensor system. In this case, there is no problem regarding temperature measurement in the normal temperature region around 25 ° C., but there is a problem in measurement accuracy in both the low temperature region and the high temperature region. In the low temperature region, the resistance value of the thermistor increases rapidly, and the CR oscillation frequency proportional to the reciprocal of the resistance value decreases. Timer 1 (18
Even if the CR oscillation frequency counter 1 (182) has the highest CR oscillation frequency during the fixed time set in 1),
Since the counter overflow is set not to occur, the count value of the CR oscillation frequency counter 1 (182) becomes small in the region where the CR oscillation frequency is low,
The relative proportion of measurement error is large. On the other hand, in the high temperature range, since the count value of the CR oscillation frequency counter 1 (182) is large, the relative ratio of the measurement error becomes small enough to be ignored, but +50 of the thermistor B (830) graph is obtained.
As shown above ℃, the amount of change in the thermistor resistance value with respect to the amount of change in temperature becomes extremely small, and as a result,
Measurement error increases. Further, as shown in the graph of the crystal oscillation frequency temperature characteristic of FIG. 6, it is a quadratic function of the temperature centered at + 25 ° C. When converting the measured temperature to the crystal oscillation frequency accuracy, the square of the temperature measurement error is calculated. Since the crystal oscillation frequency error is generated in proportion to, the influence of the temperature measurement error increases as the temperature goes to the low temperature region and the high temperature region. Therefore,
The temperature correction accuracy of the timekeeping value also has the drawback of remarkably decreasing in the low temperature region and the high temperature region. In order to compensate for this drawback, temperature correction of the two-sensor type is effective. As an example of the present invention,
The thermistor C (840) for low temperature range shown in FIG. 8 is used for the thermistor 1 (284), and the thermistor A (82) for high temperature range is used.
0) is used for the thermistor 2 (294). When the thermistor switching temperature T _S = + 15 ° C. (860) is set, the measurement temperature range (850) is divided into two ranges, a low temperature region of −40 ° C. to + 15 ° C. and a high temperature region of + 15 ° C. to + 70 ° C. Low temperature thermistor C (840) is -40 ° C
High-accuracy measurement is possible in the low temperature range of up to + 15 ° C. Similarly, the high temperature thermistor A (820) is + 15 ° C to +7.
Highly accurate measurement is possible in the high temperature range of 0 ° C. In the flowchart of FIG. 5, first, the temperature is measured by the thermistor for low temperature 1 (284) and the temperature measuring circuit 1 (283) (510, 5
11, 512, 513, 514, 515, 520) and compares the measured temperature with the sensor switching temperature (52).
1). When the measured temperature is higher than the sensor switching temperature, the high temperature thermistor 2 (294) and the temperature measuring circuit 2
At (293), the temperature is measured again (530, 53).
1, 532, 533, 534, 535, 540). If the measured temperature is lower than the sensor switching temperature, do not re-measure. From the highly accurate measured temperature obtained above, the crystal oscillation frequency deviation is obtained (550), the correction value of the interrupt cycle is calculated (560), the temperature-corrected time value is calculated (570), and the timer interrupt is generated. The process of completing the subroutine (580) is exactly the same as in the case of the one-sensor system. In the flowchart of FIG. 5, the data table conversion is used as the method of obtaining the crystal oscillation frequency deviation from the temperature (550), but the conversion by the calculation method can also be used.

By the above control, it is possible to obtain a highly accurate temperature-corrected time value. Even if a relatively inexpensive thermistor which is commonly used is used, temperature measurement of about ± 1 ° C. can be easily realized. In the example of the crystal oscillation frequency temperature characteristic of FIG. 6, the trial calculation of the influence of the measured temperature error on the measured value error will be made. First, the graph of the crystal oscillation frequency temperature characteristic is given by the following quadratic function formula.

Δf (T) / f = −a (T-25) ² (6000) a = 0.033 (6001) When this is differentiated by the temperature T, the slope of the graph is obtained. .

Δ (Δf (T) / f) / ΔT = -2a (T-25) (6002) When the interrupt cycle τ _{0 of the} timer ₀ is 1 Hz, τ ₀ = 1 [sec] ... Since (6004), Δτ (T) = − τ ₀ × Δf (T) / f (34
0) Substituting into equation (340) gives Δτ (T) = − Δf (T) / f (6005). Therefore, the error of the correction value Δτ (T) of the timer 0 interrupt cycle due to the measurement temperature error, that is, the error Δt (T) of the time-corrected time value is calculated by the following arithmetic expression.

Δt (T) = ΔT × Δ (Δτ (T)) / ΔT (6006) Substituting the equation (6005) into the equation, Δt (T) = ΔT × Δ (−Δf (T) / f) / ΔT ... (6007) Further, substituting the equation (6002) results in Δt (T) = 2a (T−25) ΔT ... (6008), and substituting the coefficient (6001) of this example, Δt (T) = 0.066 (T−25) ΔT (6009) is obtained.

When the temperature measurement error ΔT = ± 1 ° C., the equation (6)
From (009), Δt (T) = ± 0.066 (T−25) (6010), and when the time value error Δt [ppm] after temperature correction at each temperature is calculated in the equation (6010), It becomes the following value.

[0062] In the conventional method of correcting the temperature in the frequency dividing stage, in order to correct the temperature of the crystal oscillation frequency, the crystal oscillation clock of 32.768 KHz is adjusted to 1 or 2 per second depending on the temperature.
Pulse was added, but 1 pulse width is 30.5μse
Since it is c, the temperature correction accuracy of the measured value is 30.5 pp
The limit was m (30.5 μsec / 1 sec). In the embodiment of the present invention, the crystal oscillation frequency temperature characteristic is expressed by the above formula (6).
000), the error of the temperature correction itself is almost 0, and the error of the measured value due to the temperature measurement error ΔT = ± 1 ° C. is ± 4.3 ppm (T = −40) at worst.
It is possible to realize a high-accuracy time measuring device (° C). Furthermore, by using the above multiple sensor method with a high precision thermistor,
It is also possible to measure the temperature up to about 0.05 ° C. The temperature correction of the measured value in that case can be realized with higher accuracy.

When the temperature measurement error ΔT = ± 0.05 ° C.,
From the formula (6009), Δt (T) = ± 0.0033 (T-25) (6011), and the time value error Δt [ppm] after temperature correction at each temperature is calculated in the formula (6011). Then, the following values will be obtained.

[0064] In this case, Δt MAX. Value ± 0.2145 [ppm]
(T = −40 ° C.), and a highly accurate timekeeping error can be realized. When this value is converted into an annual difference, it becomes 365 [days] × 24 [hours] × 60 [minutes] × 60 [seconds] × (± 0.2145 [ppm]) = ± 6.76 [seconds], and −40 [ A time measuring device that can be used in a wide temperature range from [° C] to 70 [° C] and has a maximum annual difference of about ± 7 seconds can be realized at relatively low cost and without impairing portability.

[0065]

As described above, the time measuring device of the present invention measures the temperature at each time count for each time counting and highly accurately and in real time measures the fluctuation of the crystal oscillation frequency accuracy due to the temperature change. Since it is possible to calculate timekeeping data while making corrections, and additional parts and circuits to realize it are built in inexpensive and small thermistors, reference resistors, crystal oscillators, capacitors, clock microcomputers and microcomputers. Since it can be realized by the crystal oscillating circuit and the CR oscillating circuit, a time measuring device can be realized which is inexpensive, small in size, and highly accurately temperature-corrected for the time measured data.

Furthermore, by displaying or outputting the temperature measured for the time data correction, it is possible to add a thermometer function to the time measuring device.

[Brief description of drawings]

FIG. 1 is a block diagram of a digital timepiece having a one-sensor type temperature correction timekeeping function under microcomputer control, which is an embodiment of the present invention.

FIG. 2 is a block diagram of a digital timepiece having a two-sensor type temperature correction timekeeping function under microcomputer control, which is an embodiment of the present invention.

FIG. 3 is a control flowchart of a temperature correction timekeeping function for obtaining a crystal oscillation frequency deviation from temperature by converting a data table.

FIG. 4 is a control flowchart of a temperature correction timekeeping function for obtaining a crystal oscillation frequency deviation from temperature by a square calculation.

FIG. 5 is a control flowchart of a temperature correction timekeeping function using a two-sensor system for low temperature and high temperature.

FIG. 6 is a graph of crystal oscillation frequency accuracy temperature characteristics.

FIG. 7 is a configuration diagram of time measurement data on a data RAM.

FIG. 8 is a graph of resistance-temperature characteristics of a temperature sensor (thermistor).

[Explanation of symbols]

100 ... Microcomputer 110 ... CPU 111 ... Bus 120 ... ROM 130 ... RAM 140 ... I / O 141 ... Time data output 142 ... Operation SW 150 ... LCD driver 151 ・ ・ ・ LCD panel 160 ・ ・ ・ Crystal oscillator circuit 161 ・ ・ ・ Crystal oscillator 162 ・ ・ ・ C0 170 ・ ・ ・ Frequency divider circuit 171 ・ ・ ・ Timer 0 172 ・ ・ ・ 1 Hz interrupt generation circuit 180 ・..Temperature measuring circuit 1 181 ... Timer 1 182 ... CR oscillation frequency counter 1 183 ... CR oscillation circuit 1 184 ... Thermistor 1 185 ... C1 186 ... Reference resistance 1 200 ... Microcomputer 210 ... CPU 211 ... Bus 220 ... ROM 230 ... RAM 240 ... I / O 24・ ・ ・ Time data output 242 ・ ・ ・ Operation SW 250 ・ ・ ・ LCD driver 251 ・ ・ ・ LCD panel 260 ・ ・ ・ Crystal oscillator circuit 261 ・ ・ ・ Crystal oscillator 262 ・ ・ ・ C0 270 ・ ・ ・ Division circuit 271 ... Timer 0 272 ... 1 Hz interrupt generation circuit 280 ... Temperature measurement circuit 1 281 ... Timer 1 282 ... CR oscillation frequency counter 1 283 ... CR oscillation circuit 1 284 ... Thermistor 1 285 ... C1 286 ... Reference resistance 1 290 ... Temperature measuring circuit 1 291 ... Timer 2 292 ... CR oscillation frequency counter 2 293 ... CR oscillation circuit 2 294 ... Thermistor 2 295 ··· C2 296 ··· reference resistor _{2 300 ··· INT, τ 0 310} ··· CR · OSC: on 311 ··· timer 1: sta t 312 ... CR / CNT: up 313 ... Timer 1: OVF 314 ... CR / CNT: stop 315 ... CR / OSC: off 320 ... CNT (T)-> T 330 ... T-> Δf (T) / f 340 ... Δτ (T) = − τ ₀ × Δf (T) / f 350 ... tnew (T) = tpre (T) + τ ₀ + Δτ
(T) 360 ... RET 400 ... INT, τ ₀ 410 ... CR / OSC: on 411 ... Timer 1: start 412 ... CR / CNT: up 413 ... Timer 1: OVF 414 ... CR / CNT: stop 415 ... CR / OSC: off 420 ... CNT (T)-> T 430 ... Δf (T) / f = -a (T-T ₀ ) ² 440・ ・ ・ Δτ (T) = − τ ₀ × Δf (T) / f 450 ・ ・ ・ tnew (T) = tpre (T) + τ ₀ + Δτ
(T) 460 ... RET 500 ... INT, τ ₀ 510 ... CR / OSC1: on 511 ... Timer 1: start 512 ... CR / CNT1: up 513 ... Timer 1: OVF 514 ... CR / CNT1: stop 515 ... CR / OSC1: off 520 ... CNT (T)-> T 521 ... T> T _s 530 ... CR / OSC2: on 531 ... Timer 2: start 532 ... CR / CNT2: up 533 ... Timer 2: OVF 534 ... CR / CNT2: stop 535 ... CR / OSC2: off 520 ... CNT (T)-> T 550 ... T-> Δf (T) / f 560 ... Δτ (T) = − τ ₀ × Δf (T) / f 570 ... tnew (T) = tpre (T) + τ ₀ + Δτ
(T) 580 ... RET 600 ... Frequency accuracy Δf / f (ppm): Vertical axis 610 ... Temperature (° C.): Horizontal axis 620 ... 25 ° C. Central point 630 ... Temperature characteristic graph 700 ... CNT (temperature measurement CR oscillation frequency counter) 710 ... T (measurement temperature) 720 ... Δf / f (crystal oscillation frequency deviation) 730 ... Δτ (temperature correction value of clock interrupt period) 740・ ・ ・ Tpre (previous time measurement value) 750 ・ ・ ・ τ ₀ (room temperature value of time measurement interrupt cycle) 760 ・ ・ ・ Δτ (temperature correction value of time measurement interrupt cycle) 770 ・ ・ ・ tnew (new time measurement value) 780 ... Display data for digital clock 800 ... Thermistor resistance (KΩ): Vertical axis 810 ... Temperature (° C): Horizontal axis 820 ... A 830 ... B 840 ... C 850 ... Measuring temperature range 860 ..Thermistor switching temperature T _S

Claims (9)

[Claims] 1. A crystal oscillator, an oscillation frequency adjusting capacitor and a crystal oscillation circuit; b) a temperature sensor and a temperature measuring circuit; c) a frequency dividing circuit for converting a signal from the crystal oscillation circuit into a clock signal. And d) a storage device containing temperature characteristic data of the oscillation frequency deviation of the crystal oscillator, e) means for measuring the temperature by the temperature measuring circuit each time the clock signal is generated, and f) the temperature. After the measurement, the oscillation frequency deviation corresponding to the measured temperature read from the storage device, and a multiplication operation of the clock signal period at room temperature output from the frequency divider circuit,
Means for obtaining a temperature correction value for the timekeeping signal cycle; and g) adding the temperature measurement value for the room temperature time and the temperature correction value for the timekeeping signal to the timekeeping value after obtaining the temperature correction value for the timekeeping signal cycle. And a means for performing a timekeeping method. 2. A) a crystal oscillator, a crystal oscillation circuit requiring an oscillation frequency adjusting capacitor as an external component, b) a temperature measuring circuit requiring a temperature sensor as an external component, and c) the crystal. A frequency dividing circuit for converting a signal from an oscillation circuit into a clock signal; d) a storage device containing temperature characteristic data of oscillation frequency deviation of the external crystal oscillator; e) every time the clock signal is generated, Means for performing temperature measurement by the temperature measuring circuit; and f) an oscillation frequency deviation corresponding to the measured temperature read from the storage device after the temperature measurement, and a clock signal period at room temperature output from the frequency dividing circuit. Multiplication operation of
Means for obtaining a temperature correction value for the timekeeping signal cycle; and g) adding the temperature measurement value for the room temperature time and the temperature correction value for the timekeeping signal to the timekeeping value after obtaining the temperature correction value for the timekeeping signal cycle. A semiconductor device comprising: 3. A semiconductor device according to claim 2, b) a crystal oscillator and an oscillation frequency adjusting capacitor, c) a plurality of temperature sensors having different operating temperature ranges, d) an operation input device, and e. ) A time value display device and an output device, and f) The time measurement device according to claim 1 is used. 4. A crystal oscillator, an oscillation frequency adjusting capacitor and a crystal oscillation circuit, b) a temperature sensor and a temperature measuring circuit, and c) a frequency dividing circuit for converting a signal from the crystal oscillation circuit into a clock signal. D) means for calculating the temperature characteristic data of the oscillation frequency deviation of the crystal oscillator by calculation; e) means for measuring the temperature by the temperature measuring circuit each time the clock signal is generated; and f) the above. Means for obtaining a temperature correction value of the clock signal period by performing a multiplication calculation of the oscillation frequency deviation corresponding to the measured temperature calculated by the calculation and the clock signal period at room temperature output from the frequency dividing circuit after the temperature measurement. And g) means for performing a calculation of adding the temperature correction value of the normal temperature time and the temperature correction value of the time measurement signal to the time measurement value after obtaining the temperature correction value of the time measurement signal cycle. And total Method. 5. A crystal oscillator circuit which requires a crystal oscillator and an oscillation frequency adjusting capacitor as an external component, b) a temperature measuring circuit which requires a temperature sensor as an external component, and c) the crystal. A frequency dividing circuit for converting the signal from the oscillation circuit into a time signal, d) means for calculating temperature characteristic data of the oscillation frequency deviation of the external crystal oscillator, and e) every time the time signal is generated. Means for performing temperature measurement by the temperature measurement circuit, and f) an oscillation frequency deviation corresponding to the measured temperature calculated by the calculation after the temperature measurement, and a clock signal period at room temperature output from the frequency dividing circuit. Means for calculating the temperature correction value of the timekeeping signal cycle, and g) obtaining the temperature correction value of the timekeeping signal cycle, and then calculating the temperature correction value of the room temperature time and the temperature correction value of the timekeeping signal. Total Wherein a has a means for performing the addition operation to the value, a. 6. A semiconductor device according to claim 5, b) a crystal oscillator and a capacitor for adjusting an oscillation frequency, c) a plurality of temperature sensors having different operating temperature ranges, d) an operation input device, and e. ) A time display device and an output device for displaying the time value, and f) The time measurement device according to claim 4 is used. 7. A crystal oscillator, an oscillation frequency adjusting capacitor and a crystal oscillation circuit; b) a plurality of temperature sensors having different operating temperature ranges and a plurality of temperature measuring circuits corresponding to each; c) the crystal oscillation A frequency dividing circuit for converting a signal from the circuit into a clock signal, and d) a storage device having built-in temperature characteristic data of the oscillation frequency deviation of the crystal oscillator, or calculating temperature characteristic data of the oscillation frequency deviation of the crystal oscillator. And e) every time the timekeeping signal is generated, the most accurate temperature measurement value is selected from a plurality of temperature sensors having different operating temperature ranges and a plurality of temperature measurement circuits corresponding to each temperature sensor, and the temperature is selected. Means for performing measurement, f) an oscillation frequency deviation corresponding to the measured temperature read from the storage device after the temperature measurement, and a clock signal period at room temperature output from the frequency dividing circuit Perform root operations,
Means for obtaining a temperature correction value for the timekeeping signal cycle; and g) adding the temperature measurement value for the room temperature time and the temperature correction value for the timekeeping signal to the timekeeping value after obtaining the temperature correction value for the timekeeping signal cycle. And a means for performing a timekeeping method. 8. A crystal oscillator, which requires a crystal oscillator and an oscillation frequency adjusting capacitor as an external component, and b) a plurality of temperature sensors each having a different operating temperature range as an external component. A plurality of corresponding temperature measuring circuits; c) a frequency dividing circuit for converting a signal from the crystal oscillation circuit into a clock signal; and d) a storage device having temperature characteristic data of an oscillation frequency deviation of the crystal oscillator incorporated therein, or Means for calculating the temperature characteristic data of the oscillation frequency deviation of the crystal oscillator by calculation; and e) a plurality of temperature sensors having different operating temperature ranges and a plurality of temperature measurements corresponding to the temperature sensors each time the clock signal is generated. Means for performing temperature measurement by selecting the most accurate temperature measurement value from the circuit; f) an oscillation frequency deviation corresponding to the measured temperature read from the storage device after the temperature measurement, and Performs multiplication operations of a timer signal period at the normal temperature which is output from the frequency divider,
Means for obtaining a temperature correction value for the timekeeping signal cycle; and g) adding the temperature measurement value for the room temperature time and the temperature correction value for the timekeeping signal to the timekeeping value after obtaining the temperature correction value for the timekeeping signal cycle. A semiconductor device comprising: 9. A semiconductor device according to claim 8, b) a crystal oscillator and a capacitor for adjusting an oscillation frequency, c) a plurality of temperature sensors having different operating temperature ranges, d) an operation input device, and e. ) A time value display device and an output device, and f) The time measurement device according to claim 7 is used.