JP3702768B2 - Clock signal supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a clock signal supply device suitable for use in a microcomputer having an operation mode and a standby mode. In place Related.
[0002]
[Prior art]
For example, OA equipment such as copiers and fax machines, personal computers, OA equipment such as peripherals of personal computers, and electric appliances such as televisions, videos, and air conditioners have clock functions or timer functions. These devices are equipped with an RTC (Real Time Clock) -IC having a time & calendar function driven by a reference clock signal (for example, 32.768 kHz), and a time signal is output from the RTC-IC.
[0003]
For example, as an example of these devices, a fuck will be described as an example.
This fax machine is turned on / off by, for example, a main switch. When the fax machine is off, the original function operation of the fax is completely stopped and only a time measurement by the RTC-IC is performed. When the fax machine is on, the original function operation is not performed. This is an operation state to be performed.
[0004]
[Problems to be solved by the invention]
Incidentally, most RTC-ICs use an X-cut tuning fork type crystal resonator of 32.768 kHz, and it is generally widely known that the resonance frequency of this type of crystal resonator has a large temperature dependence. It has been. Moreover, in the above-described fax or the like, by performing the original functional operation of the apparatus in the operating state, the ambient temperature of the RTC-IC is significantly increased compared to the standby state due to the heat of the heater and the light source.
For this reason, the resonance frequency of the crystal resonator in the RTC-IC may change greatly, and the output time signal may be distorted.
[0005]
The present invention has been made in view of the above problems, and a clock signal supply device capable of performing appropriate frequency correction by monitoring the state of an external processing unit. Place The purpose is to provide.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, the invention according to claim 1 is characterized in that a reference clock signal generating means for generating a reference clock signal having a constant frequency,
A temperature correction request signal input unit to which a temperature correction request signal for determining whether or not to perform frequency fluctuation correction (temperature frequency correction) due to a change in ambient temperature is input;
Based on the temperature correction request signal, a switching signal output means for outputting a switching signal for switching the temperature frequency correction from the prohibited state to the operating state and from the operating state to the prohibited state;
Due to changes in ambient temperature frequency Fluctuating Storage means for preliminarily storing correction data used for correction as data corresponding to an elapsed time after the switching signal is switched;
Correction means for correcting the frequency of the reference clock signal based on correction data corresponding to the elapsed time when the switching signal is switched;
It is characterized by that.
[0007]
The invention according to claim 2 is the clock signal supply device according to claim 1,
The correction means includes
A slow / fast circuit for correcting the frequency of the reference clock signal;
A control register that reads correction data corresponding to the time and outputs the correction data to the slow / fast circuit;
It is characterized by that.
[0008]
According to a third aspect of the present invention, in the clock signal supply device according to the first aspect,
The correction means includes
A slow / fast circuit for correcting the frequency of the reference clock signal;
A control register that reads out correction data corresponding to the time and outputs the correction data to the slow / fast circuit;
A clock register for converting a clock signal output from the slow / fast circuit into a time signal;
It is characterized by that.
[0009]
The invention according to claim 4 is the clock signal supply device according to claim 2 or 3,
The control register measures the time from when the switching signal is switched, reads and determines correction data corresponding to the time from the storage means, and outputs the correction data to the slow / fast circuit.
It is characterized by that.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Next, preferred embodiments of the present invention will be described with reference to the drawings.
[1] First embodiment
[1.1] Schematic configuration of the first embodiment
FIG. 1 illustrates, for example, a fax machine as an apparatus on which the RTC-IC 10 according to the first embodiment is mounted, and shows a supply path of a drive voltage VCC.
The RTC-IC 10 is not limited to a fax machine, and is mounted on, for example, an OA device such as a copying machine, a personal computer, an OA device such as a peripheral device of this personal computer, an electric appliance such as a television, a video, and an air conditioner. The RTC-IC 10 supplies a time signal C to these devices.
[0029]
First, peripheral circuits of the RTC-IC 10, particularly a supply path of the drive voltage VCC will be described.
The CPU 100 is responsible for the original functional operation of the apparatus. The CPU 100 includes a RAM, a ROM, etc. (not shown), a switch 101 and a switch for setting various functions are connected to the input side, and a liquid crystal panel (both not shown). LCD (Liquid Crystal Driver Circuit) 102 for driving and a driver circuit for operating various functions are connected.
The CPU 100 receives the time signal supplied from the RTC-IC 10 in the operation mode in which the switch 101 is in the on state, displays the date and time on the liquid crystal panel via the LCD 102, while the switch 101 is off. In the standby mode in the state, the function operation controlled by the CPU 100 is stopped.
The CPU operation detection circuit 104 detects the on / off state of the switch 101 and supplies an H level temperature correction request signal A to the temperature correction request signal input terminal 12 of the RTC-IC 10 when the switch 101 is in the on state. .
The main power supply 103 generates, for example, a drive voltage VCC of 5 V by transforming and rectifying commercial power from a commercial power supply (not shown). This drive voltage VCC is supplied to the CPU 100 and the high potential side power supply terminal 17 of the RTC-IC 10.
The backup power source 105 includes a battery that generates a drive voltage VCC, and supplies the drive voltage VCC to the high potential side power supply terminal 17 of the RTC-IC 10.
A rectifier 106 is connected to the output side of the main power supply 103, and a rectifier 107 is connected to the output side of the backup power supply 105. The rectifiers 106 and 107 prevent the drive voltage VCC from being supplied to the mutual power supply.
In this manner, the CPU 100 and the RTC-IC 10 are driven by the drive voltage VCC normally supplied from the main power supply 103, and the drive voltage VCC from the backup power supply 105 is changed to the RTC-IC10 only when the supply from the main power supply 103 is stopped. To be supplied. The RTC-IC 10 is kept in an operating state by always being supplied with the drive voltage VCC from the main power source 103 or the backup power source 104.
[0030]
[1 ・ 2] Configuration of RTC10
Next, the RTC-IC 10 will be described.
Here, the RTC-IC 10 is a reference clock oscillator including an oscillator X made of, for example, a tuning fork type crystal oscillator and an oscillation circuit OSC for taking out a stable reference clock signal CLK (for example, 32.768 kHz) from the oscillator X. 11, a temperature correction request signal input terminal 12 to which a temperature correction request signal A from the CPU operation detection circuit 104 based on the mode of the CPU 100 is input, and a temperature frequency correction from a steady frequency correction based on the temperature correction request signal A Or a switching circuit 13 that outputs a switching signal B for switching from temperature frequency correction to steady frequency correction, a storage circuit 14 that stores in advance as data tables 14A and 14B (see FIG. 4) used for temperature frequency correction, and a switching circuit 13 When the switching signal B output from is switched, the data tables 14A and 14B And a correction circuit 15 for outputting a time signal C after having corrected the frequency of the reference clock signal CLK based on the correction data.
[0031]
As illustrated in FIG. 3, the RTC-IC 10 has a configuration in which components excluding the piezoelectric vibrator X are configured as an IC chip 16, and the IC chip 16 and the piezoelectric vibrator X are molded and sealed. The terminals exposed to the outside are the temperature correction request signal input terminal 12, the high potential side power supply terminal 17, the output terminal 18, and the GND terminal. The drive voltage VCC is always supplied via the high potential side power supply terminal 17. The time signal C output from the correction circuit 15 is supplied to the CPU 100 via the output terminal 18.
[0032]
Here, the steady frequency correction is to perform frequency correction by the correction circuit 15 using the predetermined steady correction data X0 when the CPU 100 is in the standby mode, and the temperature frequency correction is the CPU 100 operating mode. In this case, the frequency correction is performed by the correction circuit 15 by a process described later.
[0033]
[1-3] Configuration of the correction circuit 15
As shown in FIG. 2, the correction circuit 15 for correcting the frequency receives the logical slow / fast circuit 21 for correcting the frequency of the reference clock signal CLK, the correction signal from the switching signal B and the data tables 14A and 14B, and the logical slow / fast. A control register 22 that controls the circuit 21 and a clock register 23 that converts a signal output from the logic slow / fast circuit 21 into a time signal C are provided.
Here, when the switching signal B from the switching circuit 13 is switched, the control register 22 counts the time at this time, and reads the correction data corresponding to this time from the data tables 14A and 14B. And a function of controlling the logic slow / fast circuit 21 using the correction data as slow / fast data.
Here, the logic slow / fast circuit 21 includes a frequency divider and a shift register (none of which is shown) that shifts based on the slow / fast data. The logic slow / fast circuit 21 performs logic slow / fast in the delay or advance direction with respect to the basic clock signal CLK supplied to the frequency divider circuit by appropriately operating the state of the frequency divider circuit at a predetermined timing by the shift register. Frequency correction is performed. Since it is described in JP-A-9-127272, etc., the details thereof will be omitted.
[0034]
[1 • 4] Explanation of data tables 14A and 14B
The data tables 14A and 14B shown in FIG. 4 are stored in advance in the storage circuit 14. The data table 14A is used for temperature frequency correction at the start of correction when the switching signal B is switched from L level to H level. The data table 14B is used for temperature frequency correction at the end of correction when the switching signal B is switched from H level to L level.
[0035]
Here, generation of the data tables 14A and 14B will be described.
The RTC-IC 10 includes a reference clock oscillator 11 having a vibrator X made of a tuning fork type crystal vibrator or the like, and this tuning fork type crystal vibrator generally has frequency temperature characteristics as shown in FIG.
In the characteristic diagram of FIG. 5, the horizontal axis indicates temperature (° C.) and the vertical axis indicates frequency stability Δf / f (ppm). In this case, the change in ambient temperature is based on the frequency at 25 ° C. The frequency stability is expressed by the following equation (1).
Δf / f = a (θT−T) ² ... (1)
Here, if only the temperature characteristic represented by the above equation (1) is considered, if the temperature in the apparatus rises from 25 ° C. to 40 ° C., a frequency deviation of −7.875 ppm occurs, and from the RTC-IC 10 The clock displayed by the output time signal C is delayed by about 4 minutes per year.
[0036]
Next, temperature rise (down) in the apparatus will be described.
FIG. 6 shows a temperature rise with respect to time when the apparatus is switched from the standby mode to the operation mode by a solid line, and a temperature drop when the apparatus is switched from the operation mode to the standby mode by a dotted line. As shown in the figure, the temperature reaches a stable temperature (for example, 70 ° C.) after a predetermined time ts has elapsed since the apparatus was switched to the operation mode, and the stable temperature (for example, 70 ° C.) after the predetermined time te has elapsed since the fax was switched to the standby mode It can be seen that, for example, 25 ° C.). That is, when the mode is switched, it takes time for the temperature to stabilize, and therefore, signal frequency correction is required for each temperature.
[0037]
In consideration of these matters, the data tables 14A and 14B of FIG. 4 are created and written into the storage circuit 14 by, for example, an external controller at the time of shipment.
[0038]
The data tables 14A and 14B will be further described in detail.
First, in the data table 14A used for temperature frequency correction when the apparatus is switched from the standby mode to the operation mode, the temperature hardly changes when the start time ts measured from the switching timing is less than ts1. Therefore, the correction data is the steady correction data X0 used for the steady frequency correction in the standby mode, and thereafter the temperature T in FIG. 6 and the frequency temperature in FIG. 5 each time ts1, ts2,. From the characteristics, the start correction data corresponding to each start time is Xs1, Xs2,..., And when the apparatus temperature T is stabilized at the maximum temperature, that is, after the start time tsn, the correction data is constant Xsn.
On the other hand, the data table 14B used for temperature frequency correction when the apparatus is switched from the operation mode to the standby mode hardly changes at the maximum temperature when the end time te measured from the switching timing is less than te1. For this reason, the correction data is the start correction data Xsn corresponding to the temperature T at the time of switching, and thereafter from the temperature T in FIG. 6 and the frequency temperature characteristics in FIG. 5 every time te1, te2,. The end correction data corresponding to each end time is Xe1, Xe2,..., And when the apparatus temperature T is stable at normal temperature, that is, after the end time tsm, the end correction data is X0.
As described above, the data tables 14A and 14B in FIG. 4 are created by the correction data X corresponding to the time corresponding to the temperature rise or fall in the apparatus.
[0039]
[1.5] Operation of control register 22
Next, the operation of the control register 22 will be described with reference to the flowchart of FIG.
Actually, the control register 22 is constituted by a logic circuit, but in order to clarify the processing operation, it will be described here using a flowchart.
[0040]
First, the control register 22 supplies the steady correction data X0 to the logic slow / fast circuit 21 when the device is in the standby mode, that is, at room temperature, and the logic slow / fast circuit 21 receives the received steady correction data X0. As the fast / slow data, logical fast / slow is performed and the steady frequency correction of the clock signal CLK is performed.
Here, when the switch 101 of the apparatus is switched from the OFF state to the ON state, and the CPU 100 is switched from the standby mode to the operation mode, the CPU operation detection circuit 104 sends an H level temperature correction request signal A to the temperature of the RTC-IC 10. Output to the correction request signal input terminal 12. The switching circuit 13 receives the temperature correction request signal A supplied via the temperature correction request signal input terminal 12, and switches the switching signal B from the L level to the H level. Thereby, the temperature frequency correction process is started.
[0041]
First, the control register 22 resets and starts the start timer ts (step S1), and reads the data table 14A from the storage circuit 14 (step S2). Next, the control register 22 starts the time ts at time ts1. It is determined whether or not the time ts1 has been reached (step S3; NO), the steady correction data X0 is supplied to the logic slow / fast circuit 21 as slow / fast data. Then, the logic slow / fast circuit 21 performs the logic slow / fast process using the correction data X0 as the slow / fast data (step S4).
Thereby, the logic slow / fast circuit 21 performs steady frequency correction at room temperature until the start time ts reaches time ts1, and outputs the corrected signal to the clock register 23. The clock register 23 receives this signal. The time signal C is supplied from the output terminal 18 to the CPU 100 of the apparatus.
[0042]
On the other hand, when the start time ts has passed the time ts1 (step S3; YES), the start correction data Xs corresponding to the times ts1, ts2,... Data Xs is supplied to the logic slow / fast circuit 21 as slow / fast data. Then, the logic slow / fast circuit 21 performs the logic slow / fast process using the correction data Xs as the slow / fast data (step S5).
As a result, the logic slow / fast circuit 21 performs temperature frequency correction based on the start correction data Xs1, Xs2 corresponding to the times ts1, ts2,..., And outputs the corrected signal to the clock register 23. In response to this signal, a time signal C is supplied from the output terminal 18 to the CPU 100 of the apparatus.
[0043]
The control register 22 determines whether or not the start time ts has reached the time tsn at which the temperature in the apparatus is stable at the maximum temperature (step S6). If not reached (step S6; NO), the control register 22 If the process is repeated and reached (step S6; YES), since the temperature in the apparatus is stable, the start correction data Xsn is supplied to the logic slow / fast circuit 21 as slow / fast data (step S7). Then, the logic slow / fast circuit 21 performs the logic slow / fast process using the correction data Xsn as the slow / fast data (step S7).
[0044]
Thereafter, the control register 22 monitors the switching signal B from the switching circuit 13 (step S8), and steps until the switching signal B switches from the H level to the L level, that is, until the apparatus switches from the operation mode to the standby mode. The process of S7 is continued.
[0045]
When the switch 101 is switched from the on state to the off state and the device is switched from the operation mode to the standby mode, that is, when the switching signal B output from the switching circuit 13 is switched from the H level to the L level ( Step S8; YES), the control register 22 resets and starts the end timer te (Step S9), and reads the data table 14B from the storage circuit 14 (Step S10).
[0046]
Next, until the end time te reaches the time te1, the control register 22 supplies the end correction data Xen as the slow / fast data to the logic slow / fast circuit 21, performs frequency correction at the maximum temperature, and the corrected signal is the clock register. The clock register 23 receives this signal and supplies the time signal C from the output terminal 18 to the CPU 100 of the apparatus.
[0047]
On the other hand, when the end time te has passed the time te1, the end correction data Xe corresponding to each of the times te1, te2,... Determined in advance by the data table 14B is read, and this end correction data Xe is used as the slow / slow data. This is supplied to the logic slow / fast circuit 21. Then, the logic slow / fast circuit 21 performs the logic slow / fast process using the correction data Xe as the slow / fast data (step S11).
As a result, the logic slow / fast circuit 21 performs temperature frequency correction based on the end correction data Xe1, Xe2,... Corresponding to the times te1, te2,... And outputs the corrected signal to the clock register 23. 23 receives this signal and supplies the time signal C from the output terminal 18 to the CPU 100 of the apparatus.
[0048]
The control register 22 determines whether or not the start time te has reached a time tem at which the temperature inside the apparatus is stabilized at room temperature (step S12). If not (step S12; NO), the process of step S11 is performed. Is repeated (step S12; YES), the temperature frequency correction is terminated assuming that the temperature inside the apparatus is normal.
Thereafter, the control register 22 supplies the steady correction data X0 as the slow / fast data to the logical slow / fast circuit 21, and the logical slow / fast circuit 21 performs the logical slow / fast using the steady correction data X0 as the slow / fast data and performs normal frequency processing.
[0049]
[1.6] Effects of the first embodiment
As described above, the RTC-IC 10 according to the present embodiment uses the temperature correction request signal A input to the temperature correction request signal input terminal 12 even when the piezoelectric vibrator X having high temperature dependency is used. When the operation state (operation mode or standby mode) is monitored and the apparatus operation state is switched, correction data as slow / fast data is supplied from the control register 22 to the logical slow / fast circuit 21 in a gradually variable manner.
As a result, regardless of the temperature change in the apparatus, the logic slow / fast circuit 21 supplies a signal having a stable frequency to the clock register 23, and supplies a time signal from the clock register 23 to the external CPU 100 via the output terminal 18. . As a result, the reliability of the time signal output from the RTC-IC 10 can be improved.
[0050]
[1.7] Modification of the first embodiment
In the first embodiment, the drive voltage VCC is always supplied from the main power supply 103 to the high potential side power supply terminal 17. However, as shown in FIG. 8, the main power supply 103 is driven and controlled by the switch 101. The drive voltage VCC may be supplied from the main power supply 103 when the CPU 100 is set to the operation mode. In this case, a main power supply detection circuit 110 that generates a temperature correction request signal A corresponding to the operation state of the apparatus may be connected between the main power supply 103 and the rectifier 106.
Also in the modified example configured as described above, when the drive voltage VCC from the main power supply 103 is supplied to the high potential side power supply terminal 17 of the CPU 100 and the RTC-IC 10, the main power supply detection circuit 110 requests the H level temperature correction. The signal A is supplied to the temperature correction request signal input terminal 12. Thereby, in RTC-IC10, the frequency correction corresponding to the temperature change in an apparatus can be performed.
In addition, in this modification, when the apparatus is in the standby mode, the voltage supply from the main power supply 103 is stopped, so that the power consumption in the standby mode can be significantly reduced.
[0051]
[2] Second embodiment
The feature of the RTC-IC according to the present embodiment is that a temperature sensor is provided in the IC chip, and temperature frequency correction is performed using correction data corresponding to the temperature detected from the temperature sensor. In addition, the same code | symbol shall be attached | subjected to the component same as 1st Embodiment mentioned above, and the description shall be abbreviate | omitted.
[0052]
[2.1] Schematic configuration of the second embodiment
FIG. 9 is a diagram showing a peripheral circuit of the RTC-IC 30 according to the second embodiment, particularly a supply path of the drive voltage VCC. Since this supply path is the same as that of the first embodiment, the description thereof will be omitted.
[0053]
[2.2] Configuration of RTC30
Next, the RTC-IC 30 will be described.
Here, the RTC-IC 30 includes a reference clock oscillator 11, a temperature correction request signal input terminal 12, a switching circuit 13, and a storage circuit 32 that stores in advance as a data table 32A (see FIG. 11) used for temperature frequency correction. A temperature sensor 33 for detecting the temperature in the apparatus and a correction circuit 15 are provided.
[0054]
As in the first embodiment, the RTC-IC 30 is configured such that the component parts excluding the piezoelectric vibrator X are configured as the IC chip 16, and the IC chip 16 and the piezoelectric vibrator X are molded and sealed.
[0055]
[2.3] Configuration of correction circuit 15
As shown in FIG. 10, the correction circuit 15 for correcting the frequency includes a logical slow / fast circuit 21, a control register 22 that receives the correction data from the data table 32 </ b> A and controls the logical slow / fast circuit 21, and the logical slow / fast circuit 21. And a clock register 23 that converts a signal to be output into a time signal C.
Here, when the switching signal B from the switching circuit 13 is switched, the control register 22 stores a function for reading the temperature from the temperature sensor 31 and correction data corresponding to the read temperature as shown in FIG. A function of reading from the table 32A and a function of controlling the logical slow / fast circuit 21 using the correction data as slow / fast data are provided.
[0056]
[2.4] Explanation of data table 32A
As described in the first embodiment, the frequency of the tuning fork type crystal resonator has temperature dependence. Therefore, the data table 32A is created with correction data X corresponding to the temperature T in the apparatus, as shown in FIG.
[0057]
[2.5] Operation of control register 22
Next, the operation of the control register 22 will be described with reference to the flowchart of FIG.
Actually, the control register 22 is constituted by a logic circuit, but in order to clarify the processing operation, it will be described here using a flowchart.
[0058]
First, the control register 22 supplies the steady correction data X0 to the logic slow / fast circuit 21 when the device is in the standby mode, that is, at room temperature, and the logic slow / fast circuit 21 receives the received steady correction data X0. The steady frequency correction of the clock signal CLK is performed by using the logic as the slow / fast data.
Here, when the switch 101 of the apparatus is switched from the OFF state to the ON state, and the CPU 100 is switched from the standby mode to the operation mode, the CPU operation detection circuit 104 sends an H level temperature correction request signal A to the temperature of the RTC-IC 10. Output to the correction request signal input terminal 12. The switching circuit 13 receives the temperature correction request signal A supplied via the temperature correction request signal input terminal 12, and switches the switching signal B from the L level to the H level. Thereby, the temperature frequency correction process is started.
[0059]
First, the control register 22 reads the temperature T in the apparatus from the temperature sensor 31 (step S21), reads correction data corresponding to the temperature T from the data table 32A from the storage circuit 32 (step S22), and this correction data XT. Is supplied to the logic slow / fast circuit 21 as slow / fast data. Then, the logic slow / fast circuit 21 performs the logic slow / fast process using the correction data XT as the slow / fast data (step S23).
Thus, the logic slow / fast circuit 21 performs frequency correction corresponding to the temperature in the apparatus, and outputs the corrected signal to the clock register 23. The clock register 23 receives this signal and outputs the time signal C from the output terminal 18 to the apparatus. To the CPU 100.
Thereafter, the control register 22 monitors the switching signal B from the switching circuit 13 (step S24), and steps until the switching signal B switches from the H level to the L level, that is, until the apparatus switches from the operation mode to the standby mode. The processes after S21 are repeated.
[0060]
When the switch 101 is switched from the on state to the off state and the device is switched from the operation mode to the standby mode, the temperature correction request signal A becomes L level (step S24; YES). That is, the switching signal B output from the switching circuit 13 is switched from H level to L level. However, even when the device is switched from the operation mode to the standby mode, the temperature does not drop rapidly.
Therefore, the control register 22 reads the temperature T in the apparatus from the temperature sensor 31 (step S25), determines whether or not the temperature T is room temperature (step S26), and if it has not reached room temperature (step S26) (Step S26; NO), the correction data corresponding to the temperature T is read from the data table 32A from the storage circuit 32 (Step S27), and the logical slow / fast circuit 21 performs logical slow / fast processing using the correction data XT as slow / fast data (Step S27) S28).
On the other hand, when the temperature T reaches room temperature (step S26; YES), this temperature frequency correction process is terminated.
Then, the control register 22 supplies the steady correction data X0 as the slow / fast data to the logical slow / fast circuit 21, and the logical slow / fast circuit 21 performs the logical slow / fast process using the steady correction data X0 as the slow / fast data.
[0061]
[2.6] Effects of the second embodiment
As described above, the RTC-IC 30 according to the present embodiment includes the temperature sensor 31 in the IC chip 16, detects the temperature in the apparatus by the temperature sensor 31, and corrects the correction data from the data table 32A based on the detected temperature. XT is read out, and frequency correction is performed using the correction data XT as slow / slow data.
As a result, regardless of the temperature change in the apparatus, the logic slow / fast circuit 21 supplies a signal having a stable frequency to the clock register 23, and supplies a time signal from the clock register 23 to the external CPU 100 via the output terminal 18. . As a result, the reliability of the time signal output from the RTC-IC 30 can be improved.
[0062]
[2.7] Modification of Second Embodiment
In the second embodiment, the drive voltage VCC is always supplied from the main power supply 103 to the high potential side power supply terminal 17. However, as shown in FIG. 13, the main power supply 103 is driven and controlled by the switch 101. The drive voltage VCC may be supplied from the main power supply 103 when the CPU 100 is set to the operation mode. In this case, a main power supply detection circuit 110 that generates a temperature correction request signal A corresponding to the operation state of the apparatus may be connected between the main power supply 103 and the rectifier 106.
Also in the modified example configured as described above, when the drive voltage VCC from the main power supply 103 is supplied to the high potential side power supply terminal 17 of the CPU 100 and the RTC-IC 30, the main power supply detection circuit 110 requests the H level temperature correction. The signal A is supplied to the temperature correction request signal input terminal 12. Thereby, in RTC-IC30, the frequency correction corresponding to the temperature change in an apparatus can be performed.
In addition, in this modification, when the apparatus is in the standby mode, the voltage supply from the main power supply 103 is stopped, so that the power consumption in the standby mode can be significantly reduced.
[0063]
[3] Third embodiment
The feature of the RTC-IC according to the present embodiment is that an IC chip is provided with a temperature sensor and a data table used for temperature frequency correction is provided in an external storage means. In addition, the same code | symbol shall be attached | subjected to the component same as embodiment mentioned above, and the description shall be abbreviate | omitted.
[0064]
[3.1] Schematic configuration of the third embodiment
FIG. 14 is a diagram showing a peripheral circuit of the RTC-IC 40 according to the third embodiment, particularly a supply path of the drive voltage VCC. Since this supply path is the same as that of the first embodiment, the description thereof will be omitted.
The A / D conversion circuit 50 converts the detected temperature signal output from the temperature sensor 31 to digital, and is unnecessary when the temperature sensor 31 is provided with A / D conversion. is there.
[0065]
[3.2] Configuration of RTC40
Next, the RTC-IC 40 will be described.
Here, in addition to the reference clock oscillator 11, the temperature correction request signal input terminal 12, the switching circuit 13, the temperature sensor 31, and the correction circuit 15, the RTC-IC 40 includes a temperature signal output terminal 41 for outputting the detected temperature to the outside, a temperature And a correction signal input terminal 42 for inputting a correction signal having correction data corresponding to.
[0066]
As in the first embodiment, the RTC-IC 40 is configured such that the component parts excluding the piezoelectric vibrator X are configured as the IC chip 16, and the IC chip 16 and the piezoelectric vibrator X are molded and sealed.
[0067]
[3.3] Configuration of correction circuit 15
As shown in FIG. 15, the correction circuit 15 that corrects the frequency receives the logic slow / fast circuit 21 and correction data supplied from the outside via the correction signal input terminal 42. A control register 22 for controlling and a clock register 23 for converting a signal output from the logic slow / fast circuit 21 into a time signal C are provided.
[0068]
[3.4] Configuration of CPU 100
In this embodiment, a data table 32A for performing temperature frequency correction is stored in the CPU 100. When a detected temperature signal is output from the temperature sensor 31, the CPU 100 outputs correction data corresponding to this temperature to the RTC. -It supplies to the correction signal input terminal 42 of IC40.
[0069]
The operation of the control register 22 is different from that of the correction data XT corresponding to the temperature T in that it is read from the storage circuit 32 and that of the external CPU 100 in FIG. Since it is almost the same as the flowchart, the description thereof will be omitted.
[0070]
[3.5] Effects of the third embodiment
As described above, also in the RTC-IC 40 according to the present embodiment, the temperature in the apparatus is detected by the temperature sensor 31 provided in the IC chip 16, and the correction data XT is read from the external CPU 100 based on the detected temperature. Frequency correction is performed using the correction data XT as slow / slow data.
As a result, regardless of the temperature change in the apparatus, the logic slow / fast circuit 21 supplies a signal having a stable frequency to the clock register 23, and supplies a time signal from the clock register 23 to the external CPU 100 via the output terminal 18. . As a result, the reliability of the time signal output from the RTC-IC 40 can be improved.
In addition, unlike the other embodiments, it is not necessary to provide a data table for temperature frequency correction in the RTC-IC 40. Therefore, even after the RTC-IC 40 is incorporated in the apparatus, new correction data for temperature is newly provided. It can be set, and the correction accuracy can be further increased as compared to other embodiments.
[0071]
[3.6] Modification of Third Embodiment
[3.6.1] Modification 1
In the third embodiment, the drive voltage VCC is constantly supplied from the main power supply 103 to the high potential side power supply terminal 17. However, as shown in FIG. 16, the main power supply 103 is driven and controlled by the switch 101. The drive voltage VCC may be supplied from the main power supply 103 when the CPU 100 is set to the operation mode. In this case, a main power supply detection circuit 110 that generates a temperature correction request signal A corresponding to the operation state of the apparatus may be connected between the main power supply 103 and the rectifier 106.
Also in the modified example configured as described above, when the drive voltage VCC from the main power supply 103 is supplied to the high potential side power supply terminal 17 of the CPU 100 and the RTC-IC 40, the main power supply detection circuit 110 requests an H level temperature correction. The signal A is supplied to the temperature correction request signal input terminal 12. Thereby, in RTC-IC40, the frequency correction corresponding to the temperature change in an apparatus can be performed.
In addition, in this modification, when the apparatus is in the standby mode, the voltage supply from the main power supply 103 is stopped, so that the power consumption in the standby mode can be significantly reduced.
[0072]
[3.6.2] Modification 2
In this embodiment, the detected temperature signal from the temperature sensor 31 is output to the outside via the temperature signal output terminal 41, and correction data corresponding to the detected temperature signal is received from the outside via the correction signal input terminal 42. However, the present invention is not limited thereto, and communication means using infrared rays or electromagnetic waves may be provided at the temperature signal output terminal 41 and the correction signal input terminal 42, and signals may be exchanged with the CPU 100 using this communication means. .
[0073]
[4] Modification
[4.1] Modification 1
In the RTC-IC according to each of the above-described embodiments, the frequency of the reference clock signal CLK1 is 32.768 kHz, but the present invention is not limited to this. It is also possible to set arbitrarily.
In the embodiment, when the CPU is in the standby mode, frequency correction (steady frequency correction) is performed using the predetermined steady correction data X0. When the CPU is in the operation mode, variable correction data is used. The clock signal supply device that performs the frequency correction (temperature frequency correction) that has been performed is described as an example. However, the present invention is not limited to this, and when the CPU is in the standby mode, the reference clock signal CLK from the reference clock oscillator is output as it is without performing steady-state frequency correction, and the temperature frequency when the CPU is in the operation mode. Correction may be performed.
[0074]
[4.2] Modification 2
In each of the above embodiments, signals are exchanged with an external device via the temperature correction request signal input terminal 12, the output terminal 18, the temperature signal output terminal 41, the correction signal input terminal 42, etc. The invention is not limited to this, and a plurality of terminals may be connected to an external device through a so-called interface.
[0075]
[4.3] Modification 3
In each of the embodiments, the switching circuit 13 determines whether the operation state of the CPU 100 is the standby mode or the operation mode using the temperature correction request signal A from the CPU operation detection circuit 104 or the main power supply detection circuit 110. I did it. However, the present invention is not limited to the CPU operation detection circuit 104 or the main power supply detection circuit 110. For example, when an RTC-IC is mounted on a device that is installed outdoors, the temperature correction request signal A is determined by the operation of the switch 101. May be an output signal from the photothermal sensor, or various control signals. In short, any device that can detect that the temperature environment in the apparatus has changed can be used.
[0076]
[4.4] Modification 4
In each of the above embodiments, the case where the temperature frequency correction is performed when the temperature rises when the device enters the drive mode has been described in detail. If the temperature sometimes changes due to the influence of the outside world, it can be easily handled by switching the H level and L level of the temperature correction request signal A or the H level and L level of the switching circuit 13.
[0077]
[4.5] Modification 5
In each of the above embodiments, the frequency correction of the reference clock signal CLK is described as being performed by the logic slow / fast circuit 21. However, a frequency array is provided on the output side of the reference clock oscillator 11, and the frequency correction is performed by selecting this capacitor. You may make it use the capacity | capacitance slow / fast circuit to perform.
[0078]
[4.6] Modification 6
In the first and second embodiments, it is described that the data table is stored in the storage circuit 14 in advance. However, a data write terminal for the user to write data may be provided in the storage circuit 14 separately. In this case, data written from an external controller can be set by the user in accordance with the usage environment of the apparatus, and more accurate frequency correction can be realized.
Further, if a communication means using a coil, light such as infrared rays, or wireless communication is provided in the RTC-IC, it is possible to write data in the data table in a non-contact manner without using a data write terminal.
[0079]
【The invention's effect】
As described above, the clock signal supply device according to the present invention monitors the state of the external processing unit and enables appropriate frequency correction.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an RTC-IC and a peripheral power supply path according to a first embodiment.
FIG. 2 is a block diagram showing a configuration of an RTC-IC according to the same embodiment.
FIG. 3 is a perspective view of the RTC-IC according to the same embodiment.
FIG. 4 is a diagram showing a data table stored in a storage circuit.
FIG. 5 is a diagram showing frequency temperature characteristics of a tuning fork type crystal resonator.
FIG. 6 is a diagram showing an increase or decrease corresponding to the time of the apparatus internal temperature.
FIG. 7 is a flowchart showing temperature frequency correction processing according to the embodiment;
FIG. 8 is a block diagram showing an RTC-IC and peripheral power supply paths according to a modification of the first embodiment.
FIG. 9 is a block diagram illustrating an RTC-IC and a peripheral power supply path according to a second embodiment.
FIG. 10 is a block diagram showing a configuration of an RTC-IC according to the same embodiment.
FIG. 11 is a diagram showing a data table stored in a storage circuit.
FIG. 12 is a flowchart showing temperature frequency correction processing according to the embodiment;
FIG. 13 is a block diagram showing an RTC-IC and peripheral power supply paths according to a modification of the second embodiment.
FIG. 14 is a block diagram showing an RTC-IC and a peripheral power supply path according to a third embodiment.
FIG. 15 is a block diagram showing a configuration of an RTC-IC according to the same embodiment;
FIG. 16 is a block diagram showing an RTC-IC and peripheral power supply paths according to a modification of the third embodiment.
[Explanation of symbols]
10, 30, 40 ... RTC-IC (clock signal supply device)
11 ... Reference clock oscillator
12 ... Temperature correction request signal input terminal
13 ... switching circuit
14, 32 ... Memory circuit
14A, 14B, 32A ... Database
15 ... Correction circuit
16 ... IC chip
17 ... High potential side power supply terminal
18 ... Output terminal
21. Logic slow / fast circuit
22 ... Control register
23: Clock register
31 ... Temperature sensor
41 ... Temperature signal output terminal
42 ... Correction signal input terminal

Claims (4)

A reference clock signal generating means for generating a reference clock signal having a constant frequency;
A temperature correction request signal input unit to which a temperature correction request signal for determining whether or not to perform frequency fluctuation correction (temperature frequency correction) due to a change in ambient temperature is input;
Based on the temperature correction request signal, a switching signal output means for outputting a switching signal for switching the temperature frequency correction from the prohibited state to the operating state and from the operating state to the prohibited state;
Storage means for preliminarily storing correction data used for correcting frequency fluctuations due to a change in ambient temperature as data corresponding to an elapsed time after the switching signal is switched;
A clock signal supply device comprising: a correction unit that corrects the frequency of the reference clock signal based on correction data corresponding to the elapsed time when the switching signal is switched. The clock signal supply device according to claim 1,
The correction means includes
A slow / fast circuit for correcting the frequency of the reference clock signal;
And a control register that reads correction data corresponding to the time and outputs the correction data to the slow / fast circuit. The clock signal supply device according to claim 1,
The correction means includes
A slow / fast circuit for correcting the frequency of the reference clock signal;
A control register that reads out correction data corresponding to the time and outputs the correction data to the slow / fast circuit;
A clock signal supply device comprising: a clock register that converts a clock signal output from the slow / fast circuit into a time signal. The clock signal supply device according to claim 2 or 3,
The control register measures the time after the switching signal is switched, reads and determines correction data corresponding to the time from the storage means, and outputs the correction data to the slow / fast circuit. Clock signal supply device.

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