CN101075146A

CN101075146A - Method and apparatus for correcting

Info

Publication number: CN101075146A
Application number: CN 200710078791
Authority: CN
Inventors: 赵子羽
Original assignee: MediaTek Inc
Current assignee: MediaTek Inc
Priority date: 2006-05-19
Filing date: 2007-02-27
Publication date: 2007-11-21
Anticipated expiration: 2027-02-27
Also published as: CN100565424C

Abstract

A method for a portable device is disclosed. A reference clock is provided. A first time value and a first index are recording at a first time point. A second index is recorded at a second time point. The first time point and the second time point are counted according to the reference clock. The first index and the second index are calculated. A second time value is set according to the calculating result.

Description

Bearing calibration and device

Technical field

The invention relates to a kind of bearing calibration and device, particularly about a kind of bearing calibration and device in order to the time value of proofreading and correct real-time clock.

Background technology

Fig. 1 is the control device synoptic diagram of prior art real-time clock.As shown in the figure, control device 100 control real-time clocks (hereinafter to be referred as RTC) 180, control device 100 comprises crystal oscillator 110, second counter 120, minute counter 130, hour counter 140, daily counter 150, year counter 160 and processor 170.For example, suppose that the frequency that crystal oscillator 110 is provided is 32768Hz.

Second counter 120 is according to frequency that crystal oscillator 110 produced and pulse count.Whenever the pulse number of accumulative total reaches at 32768 o'clock, the count value of second counter 120 adds 1.Second, the stored count of counter 120 reached at 60 o'clock, and then notification signal of second counter 120 outputs makes the count value of minute counter 130 add 1 to minute counter 130, and second counter 120 finishes present counting and begins a new counting.Whenever the stored count of minute counter 130 reaches at 60 o'clock, then minute counter 130 output notice signals are to hour counter 140, and minute counter 130 finishes present counting and begins a new counting.

Whenever the stored count of hour counter 140 reaches at 24 o'clock, then hour counter 140 output notice signals are to daily counter 150, and hour counter 140 finishes present counting and begins a new counting.When the stored count of daily counter 150 countings reached a preset value, then the output notice signal arrived a year counter 160, and daily counter 150 finishes present counting and begins a new counting.

When the stored count value when changing of second counter 120, minute counter 130, hour counter 140, daily counter 150 or year counter 160, then Dui Ying counter makes the time of its renewal RTC180 with notification processor 170.

Therefore, the correctness of RTC180 is determined by the oscillation frequency that crystal oscillator 110 is produced.Yet crystal oscillator 110 is subjected to the influence of following two factors easily, and produces incorrect oscillation frequency.First influence factor is a temperature.Second influence factor is frequency shift (FS).

When variation of ambient temperature, the oscillation frequency that crystal oscillator produced can change thereupon.In addition, because the influence of technology, make the oscillation frequency that crystal oscillator produced have ± skew of 20ppm.If crystal oscillator 110 produces incorrect oscillation frequency, will cause RTC180 to produce the wrong time.

For addressing the above problem, existing way is the stored count value of proofreading and correct second counter.As shown in Figure 2, control device 200 comprises a correction buffer device 290, in order to proofread and correct RTC 280.Processor 270 upgrades the stored count value of second counter 220 according to the stored value of correction buffer device 290.Though existing settling mode can make RTC 280 have the correct time, need the extra correction buffer device 290 that increases, be used to store correct count value.Thereby cause the increase of element cost and reducing of free space.

Summary of the invention

For solving above technical matters, the invention provides a kind of bearing calibration and means for correcting.

The invention provides a kind of bearing calibration, be applicable to a portable unit.This bearing calibration comprises the following steps: to provide a reference clock; At very first time point, write down a very first time value and one first index value; At one second time point, write down one second index value.The very first time point and second time point calculate according to reference clock.Calculate first index value and second index value; According to result of calculation, set one second time value.

The present invention provides a kind of means for correcting in addition, is applicable to a portable unit.This portable unit has a real-time clock, and a very first time value can be provided.Means for correcting of the present invention comprises a counter and a processing module.One first index value and one second index value are counted and provided to counter according to a reference clock.Processing module is at very first time point, the record very first time value and first index value, at one second time point, write down second index value, calculate first index value and second index value then, make real-time clock that one second time value is provided, wherein the very first time point and second time point are to calculate according to reference clock.

Bearing calibration provided by the invention and means for correcting, by counter and index value and time value that processing module provided or write down are calculated, coming provides correct time value to real-time clock.Avoided producing the problem of the real-time clock output error time that incorrect oscillation frequency causes because of frequency generator.And need not increase extra impact damper, the cost that need not increase element just can be proofreaied and correct real-time clock.

Description of drawings

Fig. 1 is the control device synoptic diagram of an existing real-time clock.

Fig. 2 is the control device synoptic diagram of another existing real-time clock.

Fig. 3 is the synoptic diagram of the means for correcting of one embodiment of the invention.

Fig. 4 is the calculating synoptic diagram of processing module of the present invention.

Fig. 5 is the process flow diagram that is applicable to the bearing calibration of a portable unit of the present invention.

Embodiment

For above and other objects of the present invention, feature and advantage can be become apparent, cited below particularlyly go out preferred embodiment, and cooperate appended graphicly, be described in detail below.

Fig. 3 is the synoptic diagram of the means for correcting of one embodiment of the invention.Means for correcting 300 is applicable in the portable unit (for example mobile phone).Means for correcting 300 comprises a counter 310 and a processing module 320.Counter 310 is by a reference clock F _RefCount pulse make accumulated counts in the fixed cycle, and provide index value ID ₁～ID ₅Portable unit comprises real-time clock (hereinafter to be referred as RTC) 32, in order to time value TV to be provided ₁～TV ₃

At time point T1, processing module is worth TV 320 writing times ₁And index value ID ₁At time point T2, processing module 320 recording indexes value ID ₂, computation index value ID then ₁And ID ₂, so that RTC 32 provides time value TV ₂Time point T ₁And T ₂Be according to reference clock F _RefCalculate.

Means for correcting 300 also comprises frequency generator 330 and 340.Frequency generator 330 can be a crystal oscillator, in order to produce reference clock F _RefFrequency generator 340 is in order to produce a specific clock F _SPCRTC 32 is according to specific clock F _SPC, time value TV is provided ₁And TV ₃In the present embodiment, reference clock F _RefFrequency be 13MHz, and specific clock F _SPCFrequency be 32KHz.

Reference clock F _RefSide-play amount less than ± 10ppm, the frequency offset of the system clock that is produced by base station 31 is less than ± 0.05ppm.Reference clock F _RefFrequency equal the frequency of the system clock of base station 31.In certain embodiments, since the frequency offset of system clock less than reference clock F _RefSide-play amount, the reference clock F that therefore can utilize the system clock of base station 31 to come emending frequency generator 330 to be produced _Ref

As specific clock F _SPCWhen making a mistake, then the time value that provided of RTC 32 also can be incorrect.Therefore, processing module 320 will be upgraded the time value that RTC 32 is provided in a preset period.

For example, suppose that the time value that RTC 32 is provided is 01:25 (1: 25), and the time value that processing module 320 was just upgraded real-time clock every a hour and provided once.After one hour, the time value that RTC 32 is provided should be 02:25.Yet, because incorrect specific clock F _SPCInfluence, the time value that makes RTC 32 reality be provided is 02:20.Therefore, processing module 320 just is updated to 02:25 with the time value that RTC 32 is provided by 02:20.

In addition, means for correcting 300 also comprises check timer 350.Counter 310 starts according to check timer 350 and begins counting, and check timer 350 is according to reference clock F _RefPick up counting.With the GSM communication system is example, every

The stored count value of counter 310 just adds 1.

When time point T is arrived in check timer 350 timing ₁, processing module is worth TV 320 writing times ₁And index value ID ₁When time point T is arrived in check timer 350 timing ₂, processing module 320 recording indexes value ID ₂, and then according to index value ID ₁, ID ₂, indication RTC 32 provide correct time value.

From time point T ₁To time point T ₂Time should be a fixed value, but owing to comprise that the system of means for correcting 300 is busy, and make that processing module 320 can't be at time point T ₂Real time record index value ID ₂Therefore, processing module 320 will will consider the time that postpones record.

Fig. 4 is the calculating synoptic diagram of processing module.Suppose that counter was counted 780000 times in 310 1 hours, and processing module 320 was just upgraded the time value of a real-time clock every one hour.

At first, at time point T ₁The time, the time value TV that processing module 320 is recorded ₁Be 6:6:35 (6: 6: 35), and index value ID ₁Be 780000.Then, at time point T ₂The time, the index value ID that processing module 320 is recorded ₂Should be 1560000.Yet in fact,, and make the index value ID that processing module 320 is recorded because system is busy ₂Be 1561326.

Then, processing module 320 computation index value ID ₁And ID ₂Between a difference DIFF ₁Difference DIFF ₁Can be expressed from the next:

DIFF ₁＝ID ₂-ID ₁＝1561326-780000＝781326........................(1)

Then, processing module 320 is with difference DIFF ₁Convert to and be worth CTV a correction time ₁Be worth CTV correction time ₁Can be expressed from the next:

{CTV}_{1} = 781326 \times \frac{120}{26} ms = 3606.12 \sec = 3600 \sec + 6 \sec + 0.12 \sec \cdot \cdot \cdot (2)

At last, processing module is worth TV 320 computing times ₁Be worth CTV correction time ₁And, with setting-up time value TV ₂Because 3606 seconds (sec) represented 1 hour 6 seconds again, so with time value TV ₁Added 1 hour 6 seconds again, the time value TV that RTC 32 is provided ₂Set 7:6:41 (7: 6: 41) for.

In certain embodiments, at time point T ₁, processing module is worth TV 320 writing times ₁And index value ID ₁At time point T ₂, processing module is worth TV 320 writing times ₃And index value ID ₂Then, processing module 320 computation index value ID ₁And ID ₂Between difference DIFF ₂, and according to this difference DIFF ₂Adjust time value TV ₃, make real-time clock 310 that time value TV is provided ₂

For example, at time point T ₁, the time value TV that processing module 320 is recorded ₁Be 6:6:35 (6: 6: 35), and index value ID ₁Be 780000.Then, at time point T ₂, the time value TV that processing module 320 is recorded ₃Be 7:6:35 (7: 6: 35), and index value ID ₂Be 1561326.

Processing module 320 computation index value ID ₁And ID ₂Between difference DIFF ₂Difference DIFF ₂Can be expressed from the next:

DIFF ₂＝ID ₂-ID ₁＝1561326-780000＝781326........................(3)

Then, processing module 320 is according to difference DIFF ₂, try to achieve one and adjust time value ATV.Adjusting time value ATV can be expressed from the next:

ATV = (781326 - 780000) \times \frac{120}{26} ms = 6 \sec + 0.12 \sec \cdot \cdot \cdot (4)

Then, processing module 320 is adjusted time value TV according to adjusting time value ATV ₃In certain embodiments, time value TV ₂Equal time value TV ₃(7:6:35) add adjustment time value ATV (6 seconds).Therefore, can be in the hope of time value TV ₂Be 7:6:41.

In addition, because counter 310 stops counting under a sleep pattern.When making counter 310 switch to normal mode by sleep pattern, can begin counting from correct index value, means for correcting 300 also comprises a sleep module 360.The sleep module 360 in order to duration according to sleep pattern, control counter 310.

Before means for correcting 300 entered sleep pattern, the index value ID that is provided by counter 310 was provided earlier sleep module 360 ₄, the duration with sleep pattern converts a sleep index value SID to then.Leave sleep pattern and when entering normal mode, sleep module 360 is with index value ID at means for correcting 300 ₄The result of calculation that adds sleep index value SID is updated to counter 310, makes counter 310 by index value ID ₅Begin counting.In the present embodiment, index value ID ₅Be index value ID ₄With sleep index value SID's and.

For example, suppose before means for correcting 300 enters sleep pattern the index value ID that counter 310 provides ₄Be 124, and the duration of sleep pattern it is 3 seconds.Sleep module 360 first recording indexes value ID ₄, and then convert the time that sleep pattern continues to sleep index value SID.Sleep index value SID can be expressed from the next:

SID = 3 \sec \times \frac{26}{120} ks = 650 \cdot \cdot \cdot (5)

When entering normal mode leaving sleep pattern, index value ID ₅Can be expressed from the next:

ID ₅＝ID ₄+SID＝124+650＝774..........................................(6)

Therefore, when means for correcting 300 reentered normal mode, counter 310 was to begin counting by 774.

Fig. 5 is the process flow diagram of bearing calibration of the present invention.This bearing calibration is applicable in the portable unit.At first, provide a reference clock F _Ref(step S510).Because reference clock F _RefMay have offset error, so a system clock that can utilize a base station to be provided comes calibration reference clock F _Ref

At very first time point, record very first time value and first index value (step S520).With Fig. 3 is example, and processing module 320 is at time point T ₁The time, the time value TV that record RTC 32 is provided ₁Reach the index value ID that counter 310 is provided ₁In the present embodiment, RTC 32 is the specific clock F that produced according to frequency generator 340 _SPCAnd provide time value.And reference clock F _RefGreater than specific clock F _SPC

At second time point, write down second index value (step S530).In the present embodiment, the very first time point and second time point are counted according to reference clock.With Fig. 3 is example, and processing module 320 is at time point T ₂, the index value ID that recording counter 310 is provided ₂In other embodiments, processing module 320 also can write down the time value TV that RTC 32 is provided ₃

Calculate first index value and second index value (step S540).According to result of calculation, set second time value (step S550).In the present embodiment, processing module 320 computation index value ID ₁And ID ₂Between difference, and with index value ID ₁And ID ₂Between difference convert to one correction time value.At last with time value TV ₁Add one correction time value, just can try to achieve second time value.In certain embodiments, when the 3rd time value is recorded, processing module 320 is according to index value ID ₁And ID ₂Between difference, adjust the 3rd time value, in order to obtain second time value.

In addition, in other embodiments, can utilize a check timer.Check timer is according to reference clock and timing.When the check timer timing was put to the very first time, then write down the very first time value and first index value, when check timer timing during, then write down second index value to second time point.

Though the present invention discloses as above with preferred embodiment; right its is not in order to qualification the present invention, any the technical staff in the technical field, within the scope of the invention; can do some and change, so protection scope of the present invention is when being as the criterion with the scope that claim was defined.

Claims

1. a bearing calibration is applicable to a portable unit, and this bearing calibration comprises:

One reference clock is provided;

At very first time point, write down a very first time value and one first index value;

At one second time point, write down one second index value, wherein should put the very first time and this second time point is to calculate according to this reference clock;

Calculate this first index value and this second index value; And

According to this result of calculation, set one second time value.

2. bearing calibration as claimed in claim 1 is characterized in that, this step of calculating this first index value and this second index value further comprises: calculate the difference between this first index value and this second index value.

3. bearing calibration as claimed in claim 2 is characterized in that, according to this difference, sets this second time value.

4. bearing calibration as claimed in claim 2 is characterized in that, this bearing calibration further comprises:

At this second time point, write down one the 3rd time value; And

According to this difference, adjust the 3rd time value, in order to set this second time value.

5. bearing calibration as claimed in claim 1 is characterized in that, utilizes a system clock to proofread and correct this reference clock.

6. bearing calibration as claimed in claim 5 is characterized in that, this system clock is provided by a base station.

7. bearing calibration as claimed in claim 1 is characterized in that, this bearing calibration further comprises: open a check timer and come the executive logging step, this check timer is according to this reference clock and timing.

8. bearing calibration as claimed in claim 7, it is characterized in that, when this check timer timing was put to this very first time, write down this very first time value and this first index value, and when this second time point is arrived in this check timer timing, write down this second index value.

9. bearing calibration as claimed in claim 1 is characterized in that, the step of calculating this first index value and this second index value comprises:

Calculate the difference between this first index value and this second index value;

According to this reference clock, with this difference convert to one correction time value; And

Should be worth the very first time and add this of value correction time.

10. bearing calibration as claimed in claim 9 is characterized in that, this second time value equal this very first time value and this correction time value summation.

11. bearing calibration as claimed in claim 1 is characterized in that, this very first time value is provided by a specific clock, and the frequency of this reference clock is greater than the frequency of this specific clock.

12. a means for correcting is applicable to a portable unit, this portable unit has a real-time clock, and a very first time value can be provided, and this means for correcting comprises:

One first index value and one second index value are counted and provided to one counter according to a reference clock; And

One processing module, at very first time point record this very first time value and this first index value, write down this second index value at one second time point, calculate this first index value and this second index value then, make this real-time clock that one second time value is provided, wherein should put the very first time and this second time point is to calculate according to this reference clock.

13. means for correcting as claimed in claim 12 is characterized in that, this means for correcting further comprises a first frequency generator, in order to this reference clock to be provided.

14. means for correcting as claimed in claim 13 is characterized in that, this first frequency generator is a crystal oscillator.

15. means for correcting as claimed in claim 12 is characterized in that, this means for correcting further comprises a second frequency generator, and in order to a specific clock to be provided, and the frequency of this reference clock is greater than the frequency of this specific clock.

16. means for correcting as claimed in claim 15 is characterized in that, this very first time value is to be provided according to this specific clock by real-time clock.

17. means for correcting as claimed in claim 12 is characterized in that, this reference clock is proofreaied and correct by a system clock.

18. means for correcting as claimed in claim 17 is characterized in that, this system clock is provided by a base station.

19. means for correcting as claimed in claim 12 is characterized in that, this further means for correcting comprises a check timer, carries out timing according to this reference clock.

20. means for correcting as claimed in claim 19, it is characterized in that, when this check timer timing was put to this very first time, this processing module writes down this very first time value and this first index value, when this second time point was arrived in this check timer timing, this processing module write down this second index value.

21. means for correcting as claimed in claim 12 is characterized in that, this processing module is calculated the difference between this first index value and this second index value, and this real-time clock provides this second time value according to this difference.

22. means for correcting as claimed in claim 21 is characterized in that, at this second time point, this processing module is record one the 3rd time value further, and adjusts the 3rd time value according to this difference.

23. means for correcting as claimed in claim 22 is characterized in that, this second time value is this adjusted the 3rd time value.

24. means for correcting as claimed in claim 12, it is characterized in that, this processing module is calculated the difference between this first index value and this second index value, and according to this reference clock, with this difference convert to one correction time value, and calculate this very first time value and this correction time value and, to set this second time value.

25. means for correcting as claimed in claim 24 is characterized in that, this second time value equal this very first time value and this correction time value and.

26. means for correcting as claimed in claim 12 is characterized in that, under a sleep pattern, this counter stops counting, and under a normal mode, this counter continues counting.

27. means for correcting as claimed in claim 26 is characterized in that, this means for correcting further comprises a sleep module, in order to the duration according to this sleep pattern, controls this counter.

28. means for correcting as claimed in claim 27 is characterized in that, in this sleep pattern, this counter provides one the 4th index value, and at this normal mode, this counter provides one the 5th index value.

29. means for correcting as claimed in claim 28, it is characterized in that this sleep module converts the duration of this sleep pattern to a sleep index value, and the 4th index value is added this sleep index value, so that this counter under this normal mode, provides the 5th index value.

30. means for correcting as claimed in claim 29 is characterized in that, the 4th index value and this sleep index value and equal the 5th index value.

31., it is characterized in that this counter is made accumulated counts by a count pulse of this reference clock in a fixed cycle as claim 30 a described means for correcting.