CN101291143B

CN101291143B - Real-time clock integrated circuit and electronic apparatus thereof

Info

Publication number: CN101291143B
Application number: CN200710096632A
Authority: CN
Inventors: 陈泓竹; 萧建铭
Original assignee: Novatek Microelectronics Corp
Current assignee: Novatek Microelectronics Corp
Priority date: 2007-04-19
Filing date: 2007-04-19
Publication date: 2010-05-26
Anticipated expiration: 2027-04-19
Also published as: CN101291143A

Abstract

The present invention discloses a real-time clock integrated circuit and an electronic device thereof. The real-time clock integrated circuit provided by the present invention only utilizes a low-power oscillator to provide a timing reference clock required by a real-time counter, and performs the compensation to the timing reference clock with frequency drift generated by the low power oscillator in the manner of table look-up, so that not only the power consumption, production cost and design complexity of the whole real-time clock integrated circuit can be reduced simultaneously, but also the time of the timing operation of the real-time clock integrated circuit can be prolonged.

Description

Real-time clock integrated circuit and electronic installation thereof

Technical field

The present invention relates to a kind of real-time clock integrated circuit and electronic installation thereof, and be particularly related to the real-time clock integrated circuit and the electronic installation thereof of a kind of low cost, low consumpting power, low cost of manufacture and low design complexities.

Background technology

The modern life is the life of an electronization, has been full of electronic installation miscellaneous arround the life, and the function of the attached clock timing of many electronic installations meetings is wherein arranged, to increase the facility that it uses.For instance: the timing machine open/close of the subscription and video recording of videocorder or sound equipment for example, it all need have the cooperation of (Real Time Clock Integrated Circuit is called for short RTC IC) of a real-time clock integrated circuit.In addition, also all has RTC IC in personal computer, mobile phone, MP3, PDA or the camera that generally uses at present, so that after above-mentioned electronic installation cuts out main power source, allow RTC IC continue to keep the timing running, when waiting for that above-mentioned electronic installation is started shooting once more, RTC IC can supply correct gate time immediately and use for above-mentioned electronic installation.

And well known be, because RTC IC is after the main power source of above-mentioned electronic installation cuts out, its external power supply is understood stop supplies at this moment, and so RTC IC will stop its clocking capability, uses for above-mentioned electronic installation and can't supply the correct time immediately.So in order to allow RTC IC after the main power source of above-mentioned electronic installation cuts out, still continue to keep its clocking capability, lithium battery as button type (for example supply voltage be 3.0V and capacity is 50mAH) generally can be provided, with when the external power supply stop supplies of RTC IC, allow RTC IC can also continue to keep the timing running.In addition, be indebted to the progress of present semiconductor technology, RTC IC now only needs very little drive current can keep the timing running, therefore just can keep RTC IC as above-mentioned lithium battery specification and reach about running time more than 2 years.

Fig. 1 shows the existing calcspar that is applied to RTC IC 100 internal circuits in the general electronic installation.Please refer to Fig. 1, generally speaking, RTC IC 100 need by quartz (controlled) oscillator (crystal oscillator) 101 provide one accurately the timing reference clock to be used as the real-time counter reference of 103 computing times.But for will be in response to the gate time of the required application of each circuit in the electronic installation now, general RTC IC 100 is inner just must to set up some control logic circuits more, to offer the gate time of the required application of each circuit in the electronic installation now.Yet at the RTC IC 100 inner control logic circuits of being set up, it not only can cause the rising of the consumed power of RTC IC 100 more, and more can make the cost of manufacture of RTC IC 100 also promote thereupon.

So according to as can be known above-mentioned, when the consumed powers of RTC IC 100 itself rose, it can make the lithium battery specification as above-mentioned button type can provide power supply to carry out the time shortening of timing running to RTC IC 100.So in order to reach the timing running time that prolongs RTC IC 100, at first the problem that will overcome just must reduce the consumed power of RTC IC 100 itself, and the comparatively common now practice is to understand the frequency elimination that the timing reference clock that quartz (controlled) oscillator 101 is supplied passes through frequency divider (frequency divider) 102, offered afterwards now with the timing reference clock that produces appropriate frequency that each circuit uses in the electronic installation, and so the practice not only can reduce the consumed power of RTC IC 100, and more can reduce the cost of manufacture of RTC IC 100.

And it will be further appreciated that, quartz (controlled) oscillator 101 not only can provide timing reference clock comparatively accurately, and be not subject to simultaneously temperature, humidity, processing procedure, operating voltage ... etc. factor interference and the accuracy of its timing reference clock that provides is provided, so tend to needing on the electronic installation of accurate timing to be applied to.Yet though quartz (controlled) oscillator 101 has above-mentioned multiple advantages, quartz (controlled) oscillator 101 be because itself can consume more drive current on above-mentioned button type lithium battery, and institute will shorten so that RTC IC 100 carries out the time that timing operates.In addition, also common than the general market oscillator of the cost of manufacture of quartz (controlled) oscillator 101 assemblies itself (for example: ring oscillator, RC oscillator, relaxation oscillator ... etc.) all high, so make that the cost of manufacture of the RTC IC 100 that utilizes its counting also can be than higher.

And in order to reduce the consumed power of RTC IC 100, in United States Patent (USP) case number the 6th, 873, disclosed a kind of " Power down system and method for integrated circuit " for No. 215, it is by utilizing a quartz (controlled) oscillator and a low-power oscillator simultaneously in integrated circuit, wherein, when integrated circuit operation during in normal mode (that is have external power supply be supplied to the body circuit) starts quartz (controlled) oscillator, and when integrated circuit operation (that is not having external power supply to be supplied to the body circuit) startup low-power oscillator during in park mode.So because low-power oscillator itself can be on above-mentioned button type lithium battery consumes lower drive current, institute so that RTC IC 100 carry out time that timing operates also can be long.

Yet, low-power oscillator be subjected to easily environment become because of (for example: temperature, humidity, processing procedure, operating voltage ... etc.) interference and the accuracy of its timing reference clock that provides is provided.So United States Patent (USP) case number the 6th, 873, in No. 215 in the disclosed technology contents, more in integrated circuit, add transducer to measure the timing reference clock that low-power oscillator was provided, and when timing reference clock that low-power oscillator provided produces frequency drift, the timing reference clock that utilizing quartz (controlled) oscillator is again provided compensates the timing reference clock that low-power oscillator produces frequency drift, but the technological means of the timing reference clock that directly measures low-power oscillator and provided by transducer, it not only can promote the complexity of integrated circuit global design, and more can increase the cost of manufacture of integrated circuit.

Summary of the invention

In view of this, purpose of the present invention just provides a kind of real-time clock integrated circuit and uses the electronic installation of this real-time clock integrated circuit, real-time clock integrated circuit provided by the present invention only utilizes a required timing reference clock of low-power oscillator supply real-time counter, and carry out the compensation that low-power oscillator produces the timing reference clock of frequency drift by the mode of tabling look-up, so not only can reach the consumed power that reduces real-time clock integrated circuit integral body simultaneously, cost of manufacture and design complexities, and more can allow real-time clock integrated circuit carry out the time elongation of timing running.

Based on above-mentioned and other purpose, the invention provides a kind of real-time clock integrated circuit and comprise low-power oscillator, real-time counter, and control unit.Wherein, low-power oscillator is used to supply a timing reference clock, and this timing reference clock can produce the correspondent frequency drift along with the operating voltage instantly of low-power oscillator.The timing reference clock that does not produce frequency drift that the real-time counter meeting is supplied according to first counts and low-power oscillator, and obtain a fixed count time after beginning to count up to first counts, and can regularly produce a detection signal.

Control unit couples low-power oscillator and real-time counter, this control unit be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the operating voltage instantly of low-power oscillator, and from a look-up table, find out according to this low-power oscillator this instantly operating voltage the timing reference clock that does not produce frequency drift that should supply, and then judge the timing reference clock that low-power oscillator supplied instantly and whether produce frequency drift, when wherein the timing reference clock of being supplied instantly when low-power oscillator produces frequency drift, cause real-time counter to obtain the above-mentioned fixed count time after beginning to count up to second counts or the 3rd counts according to second counts or the 3rd counts.

In one embodiment of this invention, control unit comprises voltage detector, searches the unit, and compensating unit.Wherein, voltage detector couples low-power oscillator and real-time counter, after this voltage detector is used for detection signal that every reception real-time counter regularly produced, then begins to detect the operating voltage instantly of low-power oscillator.Search the unit and couple voltage detector and built-in above-mentioned look-up table, this search the unit be used for built-in look-up table find out low-power oscillator that voltage detector detects operating voltage instantly the timing reference clock that does not produce frequency drift that should supply.

Compensating unit couples searches the unit, low-power oscillator and real-time counter, this compensating unit can according to low-power oscillator operating voltage instantly the timing reference clock that does not produce frequency drift that should supply, whether produce frequency drift and judge the timing reference clock that low-power oscillator supplied instantly, and when low-power oscillator when the timing reference clock of the frequency drift that produces is higher than the timing reference clock that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter to begin to count up to second counts according to the second above-mentioned counts, and when low-power oscillator when the timing reference clock of the frequency drift that produces is lower than this timing reference clock that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter to begin to count up to the 3rd counts according to the 3rd above-mentioned counts, wherein, the second above-mentioned counts is greater than the first above-mentioned counts, and the 3rd above-mentioned counts is less than the first above-mentioned counts.

From another viewpoint, the invention provides another kind of real-time clock integrated circuit and comprise adjustable low-power oscillator, real-time counter, and control unit.Wherein, adjustable low-power oscillator is used to supply the timing reference clock, and this timing reference clock can produce the correspondent frequency drift along with the operating voltage instantly of adjustable low-power oscillator.Real-time counter couples adjustable low-power oscillator, the timing reference clock that does not produce frequency drift that this real-time counter meeting is supplied according to first counts and adjustable low-power oscillator, and obtain a fixed count time after beginning to count up to first counts, and can regularly produce a detection signal.

Control unit couples adjustable low-power oscillator and real-time counter, this control unit be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the operating voltage instantly of adjustable low-power oscillator, and from a look-up table, find out according to this adjustable low-power oscillator this instantly operating voltage the timing reference clock that does not produce frequency drift that should supply, and then judge the timing reference clock that adjustable low-power oscillator supplied instantly and whether produce frequency drift, wherein, when the timing reference clock of being supplied instantly when adjustable low-power oscillator produces frequency drift, control unit can be corresponding generation first control signal or second control signal with the timing reference clock that causes adjustable low-power oscillator to be supplied instantly be adjustable low-power oscillator operating voltage instantly the timing reference clock that does not produce frequency drift that should supply, and obtain the above-mentioned fixed count time after making real-time counter begin to count up to the first above-mentioned counts according to this.

In one embodiment of this invention, control unit comprises voltage detector and searches the unit.Wherein, voltage detector couples adjustable low-power oscillator and real-time counter, after this voltage detector is used for detection signal that every reception real-time counter regularly produced, then begins to detect the operating voltage instantly of adjustable low-power oscillator.Search the unit and couple voltage detector and adjustable low-power oscillator and built-in above-mentioned look-up table, this search the unit be used for built-in look-up table find out voltage detector detect adjustable low-power oscillator operating voltage instantly the timing reference clock that does not produce frequency drift that should supply, and corresponding according to this above-mentioned first control signal or second control signal of generation.

In one embodiment of this invention, adjustable low-power oscillator comprises first switch, first inverter, second inverter, and the 3rd inverter.Wherein, first switch couples searches the unit, and this first switch has first end, second end and control end, and the control end of this first switch is used for the first above-mentioned control signal of corresponding reception or second control signal and whether determines its conducting.First inverter has input and output, and wherein, the input of first inverter couples first end of first switch.Second inverter has input and output, and wherein, the input of second inverter couples the output of first inverter, and the output of second inverter then couples second end of first switch.The 3rd inverter has input and output, and wherein the input of the 3rd inverter couples the output of second inverter, and the output of the 3rd inverter then couples the input of first inverter.

From another viewpoint, the invention provides a kind of electronic installation and comprise real-time clock integrated circuit, and this real-time clock integrated circuit comprises low-power oscillator, real-time counter again, and control unit.Wherein, low-power oscillator is used to supply the timing reference clock, and this timing reference clock can be along with the operating voltage instantly of low-power oscillator, when lower operating temps or operational humidity and produce the correspondent frequency drift instantly.The timing reference clock that does not produce frequency drift that the real-time counter meeting is supplied according to first counts and low-power oscillator, and obtain a fixed count time after beginning to count up to first counts, and can regularly produce a detection signal.

Control unit couples low-power oscillator and real-time counter, this control unit be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the operating voltage instantly of low-power oscillator, when lower operating temps or operational humidity instantly, and from a look-up table, find out low-power oscillator according to this at this operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply, and then judge the timing reference clock that low-power oscillator supplied instantly and whether produce frequency drift, wherein, when the timing reference clock of being supplied instantly when low-power oscillator produces frequency drift, cause real-time counter to obtain the above-mentioned fixed count time after beginning to count up to second counts or the 3rd counts according to second counts or the 3rd counts.

In one embodiment of this invention, electronic installation more comprises Temperature Detector and moisture detector.Wherein, Temperature Detector couples low-power oscillator and real-time counter, this Temperature Detector be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the lower operating temps of working as of low-power oscillator.Moisture detector couples low-power oscillator and real-time counter, this moisture detector be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the operational humidity instantly of low-power oscillator.

In one embodiment of this invention, control unit comprises voltage detector and searches the unit.Wherein, voltage detector couples low-power oscillator and real-time counter, this voltage detector be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the operating voltage instantly of low-power oscillator.Search the unit and couple voltage detector, Temperature Detector and moisture detector and built-in above-mentioned look-up table, this search the unit be used for built-in look-up table find out voltage detector, Temperature Detector or low-power oscillator that moisture detector detects operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply.

Compensating unit couples searches the unit, low-power oscillator and real-time counter, this compensating unit can be according to low-power oscillator at operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply, whether produce frequency drift and judge the timing reference clock that low-power oscillator supplied instantly, and when low-power oscillator when the timing reference clock of the frequency drift that produces is higher than the timing reference clock that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter to begin to count up to second counts according to the second above-mentioned counts, and when low-power oscillator when the timing reference clock of the frequency drift that produces is lower than the timing reference clock that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter to begin to count up to the 3rd counts according to the 3rd above-mentioned counts, wherein, the second above-mentioned counts is greater than the first above-mentioned counts, and the 3rd above-mentioned counts is less than the first above-mentioned counts.

From another viewpoint, the invention provides another kind of electronic installation and comprise real-time clock integrated circuit, and this real-time clock integrated circuit comprises low-power oscillator, real-time counter again, and control unit.Wherein, low-power oscillator is used to supply the timing reference clock, and this timing reference clock can be along with the operating voltage instantly of low-power oscillator, when lower operating temps or operational humidity and produce the correspondent frequency drift instantly.The timing reference clock that does not produce frequency drift that the real-time counter meeting is supplied according to first counts and low-power oscillator, and obtain a fixed count time after beginning to count up to first counts, and can regularly produce a detection signal.

Control unit couples low-power oscillator and real-time counter, this control unit is according to the operating voltage instantly of low-power oscillator, when lower operating temps or operational humidity and from a look-up table, find out low-power oscillator instantly at this operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply, whether produce frequency drift to judge the timing reference clock that low-power oscillator supplied instantly, wherein, when the timing reference clock of being supplied instantly when low-power oscillator produces frequency drift, cause real-time counter to obtain the above-mentioned fixed count time after beginning to count up to second counts or the 3rd counts according to second counts or the 3rd counts.

In one embodiment of this invention, electronic installation more comprises voltage detector, Temperature Detector, and moisture detector.Wherein, voltage detector couples low-power oscillator and real-time counter, this voltage detector be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the operating voltage instantly of low-power oscillator.Temperature Detector couples low-power oscillator and real-time counter, this Temperature Detector be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the lower operating temps of working as of low-power oscillator.Moisture detector couples low-power oscillator and real-time counter, this moisture detector be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the operational humidity instantly of low-power oscillator.

In one embodiment of this invention, control unit comprises and searches unit and compensating unit.Wherein, search the unit and couple voltage detector, Temperature Detector and moisture detector and built-in above-mentioned look-up table, this search the unit be used for built-in look-up table find out voltage detector, Temperature Detector or low-power oscillator that moisture detector detects operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply.

Compensating unit couples searches the unit, low-power oscillator and real-time counter, this compensating unit can be according to low-power oscillator at operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply, whether produce frequency drift and judge the timing reference clock that low-power oscillator supplied instantly, and when low-power oscillator when the timing reference clock of the frequency drift that produces is higher than the timing reference clock that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter to begin to count up to second counts according to the second above-mentioned counts, and when low-power oscillator when the timing reference clock of the frequency drift that produces is lower than the timing reference clock that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter to begin to count up to the 3rd counts according to the 3rd above-mentioned counts, the second wherein above-mentioned counts is greater than the first above-mentioned counts, and the 3rd above-mentioned counts is less than the first above-mentioned counts.

From another viewpoint, the invention provides another kind of electronic installation and comprise real-time clock integrated circuit, and this real-time clock integrated circuit comprises adjustable low-power oscillator, real-time counter again, and control unit.Wherein, adjustable low-power oscillator is used to supply the timing reference clock, and this timing reference clock can be along with the operating voltage instantly of adjustable low-power oscillator, when lower operating temps or operational humidity and produce the correspondent frequency drift instantly.Real-time counter couples adjustable low-power oscillator, the timing reference clock that does not produce frequency drift that this real-time counter meeting is supplied according to first counts and adjustable low-power oscillator, and obtain a fixed count time after beginning to count up to first counts, and can regularly produce a detection signal.

Control unit couples adjustable low-power oscillator and real-time counter, this control unit be used for every reception real-time counter behind the detection signal that regularly produces, then begin to detect the operating voltage instantly of adjustable low-power oscillator, when lower operating temps or operational humidity instantly, and from a look-up table, find out adjustable low-power oscillator according to this at this operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply, and then judge the timing reference clock that adjustable low-power oscillator supplied instantly and whether produce frequency drift, wherein, when the timing reference clock of being supplied instantly when adjustable low-power oscillator produces frequency drift, control unit can be corresponding generation first control signal or second control signal be adjustable low-power oscillator at operating voltage instantly with the timing reference clock that causes adjustable low-power oscillator to be supplied instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply, and obtain the above-mentioned fixed count time after making real-time counter begin to count up to the first above-mentioned counts according to this.

In one embodiment of this invention, electronic installation more comprises Temperature Detector and moisture detector.Wherein, Temperature Detector couples adjustable low-power oscillator and real-time counter, after this Temperature Detector is used for detection signal that every reception real-time counter regularly produced, then begins to detect the lower operating temps of working as of adjustable low-power oscillator.Moisture detector couples adjustable low-power oscillator and real-time counter, after this moisture detector is used for detection signal that every reception real-time counter regularly produced, then begins to detect the operational humidity instantly of adjustable low-power oscillator.

In one embodiment of this invention, control unit comprises voltage detector and searches the unit.Wherein, voltage detector couples adjustable low-power oscillator and real-time counter, after this voltage detector is used for detection signal that every reception real-time counter regularly produced, then begins to detect the operating voltage instantly of adjustable low-power oscillator.Search the unit and couple voltage detector, Temperature Detector, moisture detector and adjustable low-power oscillator and built-in above-mentioned look-up table, this search the unit be used for built-in look-up table find out voltage detector, Temperature Detector or moisture detector detect adjustable low-power oscillator operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply, and corresponding according to this generation first control signal or second control signal.

In one embodiment of this invention, adjustable low-power oscillator comprises first switch, first inverter, second inverter, and the 3rd inverter.Wherein, first switch couples searches the unit, and this first switch has first end, second end and control end, and the control end of this first switch is used for the first above-mentioned control signal of corresponding reception or second control signal and whether determines its conducting.First inverter has input and output, and wherein, the input of first inverter couples first end of first switch.Second inverter has input and output, and wherein the input of second inverter couples the output of first inverter, and the output of second inverter then couples second end of first switch.The 3rd inverter has input and output, and wherein, the input of the 3rd inverter couples the output of second inverter, and the output of the 3rd inverter then couples the input of first inverter.

Control unit couples adjustable low-power oscillator and real-time counter, this control unit can be according to the operating voltage instantly of adjustable low-power oscillator, when lower operating temps or operational humidity and from a look-up table, find out adjustable low-power oscillator instantly at this operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply, whether produce frequency drift to judge the timing reference clock that adjustable low-power oscillator supplied instantly, wherein, when the timing reference clock of being supplied instantly when adjustable low-power oscillator produces frequency drift, generation first control signal of control unit correspondence or second control signal with the timing reference clock that causes adjustable low-power oscillator to be supplied instantly be adjustable low-power oscillator operating voltage instantly the timing reference clock that does not produce frequency drift that should supply, and obtain the above-mentioned fixed count time after making real-time counter begin to count up to the first above-mentioned counts according to this.

In one embodiment of this invention, electronic installation more comprises voltage detector, Temperature Detector, and moisture detector.Wherein, voltage detector couples adjustable low-power oscillator and real-time counter, after this voltage detector is used for detection signal that every reception real-time counter regularly produced, then begins to detect the operating voltage instantly of adjustable low-power oscillator.Temperature Detector couples adjustable low-power oscillator and real-time counter, after this Temperature Detector is used for detection signal that every reception real-time counter regularly produced, then begins to detect the lower operating temps of working as of adjustable low-power oscillator.Moisture detector couples adjustable low-power oscillator and real-time counter, after this moisture detector is used for detection signal that every reception real-time counter regularly produced, then begins to detect the operational humidity instantly of adjustable low-power oscillator.

In one embodiment of this invention, control unit comprises searches the unit, it couples voltage detector, Temperature Detector, moisture detector and adjustable low-power oscillator and built-in above-mentioned look-up table, this search the unit be used for built-in look-up table find out voltage detector, Temperature Detector or moisture detector detect adjustable low-power oscillator in operating voltage instantly, when lower operating temps or instantly operational humidity the timing reference clock that does not produce frequency drift that should supply, and corresponding according to this generation first control signal or second control signal.

In one embodiment of this invention, adjustable low-power oscillator comprises first switch, first inverter, second inverter, and the 3rd inverter.Wherein, first switch couples searches the unit, and this first switch has first end, second end and control end, and the control end of this first switch is used for the first above-mentioned control signal of corresponding reception or second control signal and whether determines its conducting.First inverter has input and output, and wherein the input of first inverter couples first end of first switch.Second inverter has input and output, and wherein, the input of second inverter couples the output of first inverter, and the output of second inverter then couples second end of first switch.The 3rd inverter has input and output, and wherein the input of the 3rd inverter couples the output of second inverter, and the output of the 3rd inverter then couples the input of first inverter.

In one embodiment of this invention, above-mentioned real-time clock integrated circuit more comprises interface bus, it couples searches unit, compensating unit and real-time counter, and the electronic apparatus system that this interface bus is used for being had according to the serial transmission protocol of standard microprocessor carries out synchronous or asynchronous setting to searching unit, compensating unit and real-time counter.

In one embodiment of this invention, above-mentioned adjustable low-power oscillator more comprises second switch, the 4th inverter, and the 5th inverter.Wherein, second switch couples searches the unit, and this second switch has first end, second end and control end, wherein, the control end of second switch be used for corresponding reception first control signal or second control signal and whether determine its conducting, first end of second switch couples the output of the 3rd inverter, second end of second switch then couples first end of first switch.The 4th inverter has input and output, and wherein, the input of the 4th inverter couples first end of second switch.The 5th inverter has input and output, and wherein, the input of the 5th inverter couples the output of the 4th inverter, and the output of the 5th inverter then couples the input of first inverter.

In one embodiment of this invention, above-mentioned look-up table is being noted down at normal temperature or very under the temperature state, low-power oscillator operating voltage instantly the characteristic curve of the timing reference clock that does not produce frequency drift that should supply.

In one embodiment of this invention, above-mentioned look-up table is being noted down at normal temperature or very under the temperature state, adjustable low-power oscillator operating voltage instantly the characteristic curve of the timing reference clock that does not produce frequency drift that should supply.

In one embodiment of this invention, above-mentioned look-up table is writing down at normal temperature or very under the temperature state, low-power oscillator operating voltage instantly, when lower operating temps and operational humidity instantly most bar characteristic curves of the timing reference clock that does not produce frequency drift that should supply.

In one embodiment of this invention, above-mentioned look-up table is being noted down at normal temperature or very under the temperature state, adjustable low-power oscillator operating voltage instantly, when lower operating temps and operational humidity instantly most bar characteristic curves of the timing reference clock that does not produce frequency drift that should supply.

Real-time clock integrated circuit provided by the present invention goes for having now in the electronic installation that needs the accurate counting time, its by with low-power oscillator under the temperature state of normal temperature/very, it is operating voltage instantly, most bar characteristic curves of the timing reference clock that does not produce frequency drift that should supply when lower operating temps and the institute of operational humidity are instantly noted down in look-up table, and the voltage detector of arranging in pairs or groups simultaneously, Temperature Detector and moisture detector detect the operating voltage instantly of low-power oscillator, when lower operating temps and operational humidity instantly, so carry out the compensation that low-power oscillator produces the timing reference clock of frequency drift in the mode of tabling look-up again.By this, real-time clock integrated circuit provided by the present invention not only can reach consumed power, cost of manufacture and the design complexities that reduces real-time clock integrated circuit integral body simultaneously, and the time that more can allow real-time clock integrated circuit carry out the timing running is elongated.

For above and other objects of the present invention, feature and advantage can be become apparent, preferred embodiment of the present invention cited below particularly, and conjunction with figs. are described in detail below.

Description of drawings

Fig. 1 shows the existing calcspar that is applied to the RTC IC internal circuit in the general electronic installation.

Fig. 2 shows the electronic installation calcspar according to preferred embodiment of the present invention.

Fig. 3 shows the schematic diagram of searching the built-in look-up table in unit.

Fig. 4 shows the electronic installation calcspar according to another preferred embodiment of the present invention.

Fig. 5 shows the circuit diagram of the adjustable low-power oscillator internal circuit of present embodiment.

The reference numeral explanation

100,201,401: real-time clock integrated circuit

101: quartz (controlled) oscillator

102: frequency divider

103: real-time counter

200,400: electronic installation

201a: low-power oscillator

201b, 401b: real-time counter

201c, 401c: control unit

201d, 401d: interface bus

203,403: electronic apparatus system

203a, 403a: microprocessor

205,405: Temperature Detector

207,407: moisture detector

209,409: voltage detector

211,411: search the unit

213: compensating unit

401a: adjustable low-power oscillator

SW1: first switch

SW2: second switch

INV1: first inverter

INV2: second inverter

INV3: the 3rd inverter

INV4: the 4th inverter

INV5: the 5th inverter

CLKB: timing reference clock

DS: detection signal

Vosc: the operating voltage instantly of low-power oscillator and adjustable low-power oscillator

CS1: first control signal

CS2: second control signal

Embodiment

The technology effect that the present invention desired to reach is that the consumed power of real-time clock integrated circuit integral body, cost of manufacture and design complexities are reduced, and the time that allows real-time clock integrated circuit carry out the timing running is elongated.And following content will be to do one at the technical characterictic of this case and the effect desiring to reach to encyclopaedize, and consider and examine to offer this invention those skilled in the relevant art.

Fig. 2 shows electronic installation 200 calcspars according to preferred embodiment of the present invention.Please refer to Fig. 2, the electronic installation 200 of present embodiment for example can be videocorder, sound equipment, personal computer, mobile phone, MP3, PDA, camera ... etc., but and be subject to this, and it comprises real-time clock integrated circuit (Real Time ClockIntegrated Circuit, be called for short RTC IC) 201, electronic apparatus system 203, Temperature Detector 205, and moisture detector 207.Wherein, RTC IC 201 is used to supply when correct gate time is in machine open/close for electronic installation 200 and uses.

In the present embodiment, RTC IC 201 comprises low-power oscillator 201a, real-time counter 201b, control unit 201c, and interface bus 201d.Wherein, low-power oscillator 201a can select ring oscillator (ring oscillator), RC oscillator (RC oscillator), relaxation oscillator (relaxation oscillator) for use ... wait one of them, but be not limited to this, this low-power oscillator 201a is used to supply a timing reference clock CLKB, and this timing reference clock CLKB can produce the correspondent frequency drift along with the Vosc of operating voltage instantly of low-power oscillator 201a.

The timing reference clock CLKB that does not produce frequency drift that real-time counter 201b is supplied according to first counts and low-power oscillator 201a, and obtain a fixed count time after beginning to count up to first counts, and regularly (for example be per 30 seconds, but be not limited to this) produces a detection signal DS.For instance: at first, suppose that the first above-mentioned counts is 1000 times, when then real-time counter 201b begins to count the timing reference clock that does not produce frequency drift that low-power oscillator 201a supplied CLKB to 1000 time, for example can obtain 1 second fixed count time.

Control unit 201c couples low-power oscillator 201a and real-time counter 201b, this control unit 201c be used for every reception real-time counter 201b behind the detection signal DS that regularly produces, then begin to detect the Vosc of operating voltage instantly of low-power oscillator 201a, and from a look-up table, find out according to this low-power oscillator 201a this instantly operating voltage Vosc the timing reference clock CLKB that does not produce frequency drift that should supply, and then judge the timing reference clock CLKB that low-power oscillator 201a supplied instantly and whether produce frequency drift, wherein, when the timing reference clock CLKB that is supplied instantly as low-power oscillator 201a produces frequency drift, cause real-time counter 201b to obtain the above-mentioned fixed count time after beginning to count up to second counts or the 3rd counts according to second counts or the 3rd counts.

In the present embodiment, control unit 201c comprises voltage detector 209, searches unit 211, and compensating unit 213.Wherein, voltage detector 209 couples low-power oscillator 201a and real-time counter 201b, after this voltage detector 209 is used for detection signal DS that every reception real-time counter 201b regularly produced, then begin to detect the Vosc of operating voltage instantly of low-power oscillator 201a.Search unit 211 and couple voltage detector 209 and built-in above-mentioned look-up table, this search unit 211 be used for built-in look-up table find out the voltage detector 209 low-power oscillator 201a that detects operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply.

Compensating unit 213 couples searches unit 211, low-power oscillator 201a and real-time counter 201b, this compensating unit 213 can according to low-power oscillator 201a operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply, whether produce frequency drift and judge the timing reference clock CLKB that low-power oscillator 201a supplied instantly, and as low-power oscillator 201a when the timing reference clock CLKB of the frequency drift that produces is higher than the timing reference clock CLKB that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter 201b to begin to count up to second counts according to the second above-mentioned counts, and as low-power oscillator 201a when the timing reference clock CLKB of the frequency drift that produces is lower than this timing reference clock CLKB that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter 201b to begin to count up to the 3rd counts according to the 3rd above-mentioned counts, wherein, the second above-mentioned counts is greater than the first above-mentioned counts, and the 3rd above-mentioned counts is less than the first above-mentioned counts.

Interface bus 201d couples and searches unit 211, compensating unit 213 and real-

time counter

201b, and 203 pairs of the electronic apparatus systems that this interface bus 201d is used for being had according to the serial transmission protocol of standard microprocessor 203a are searched unit 211, compensating unit 213 and real-time counter 201b and carried out synchronous or asynchronous setting.Wherein, this interface bus 201d for example can be internal integrated circuit (innerintegrated circuit, I ²C) bus, serial peripheral interface (serial peripheralinterface, SPI) bus, little line interface (microwire interface) bus or control area net network (controller area network bus, CAN) bus ... etc., but be not limited to this.

Temperature Detector 207 couples low-power oscillator 201a and real-time counter 201b, this Temperature Detector 207 be used for every reception real-time counter 201b behind the detection signal DS that regularly produces, then begin to detect the lower operating temps of working as of low-power oscillator 201a.Moisture detector 209 couples low-power oscillator 201a and real-time counter 201b, this moisture detector 209 be used for every reception real-time counter 201b behind the detection signal DS that regularly produces, then begin to detect the operational humidity instantly of low-power oscillator 201a.

Fig. 3 shows the schematic diagram of searching the built-in look-up table in unit 211.Please merge with reference to Fig. 2 and Fig. 3, search unit 211 built-in look-up tables and writing down at normal temperature or very under the temperature state, low-power oscillator 201a operating voltage Vosc instantly, when lower operating temps and operational humidity instantly most bar characteristic curves of the timing reference clock CLKB that does not produce this frequency drift that should supply.After following content will receive the detection signal DS of real-time counter 201b institute timing generation with voltage detector 209 earlier, the overall operation flow process of the inside of RTC IC 201 illustrated.

In the present embodiment, when voltage detector 209 receive real-time counter 201b behind the detection signal DS that regularly produces, just can begin to detect the Vosc of operating voltage instantly of low-power oscillator 201a, and search this moment unit 211 can in built-in look-up table, find out the voltage detector 209 low-power oscillator 201a that detects operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply.

What deserves to be mentioned is earlier at this, the accuracy of its timing reference clock CLKB that provides because being subjected to the change of operating voltage Vosc easily, low-power oscillator 201a is provided, so as low-power oscillator 201a when the timing reference clock CLKB of the frequency drift that produces is higher than the timing reference clock CLKB that does not produce frequency drift instantly, this moment is if real-time counter 201b is higher than the timing reference clock CLKB that do not produce frequency drift according to this after beginning to count up to above-mentioned first counts of giving an example (that is 1000 times), what well imagine is that the resulting fixed count time of real-time counter 201b can be less than 1 second.

So compensating unit 213 this moment then can according to search unit 211 in built-in look-up table, find out the voltage detector 209 low-power oscillator 201a that detects operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply, whether produce frequency drift and judge the timing reference clock CLKB that low-power oscillator 201a supplied instantly, and as low-power oscillator 201a when the timing reference clock CLKB of the frequency drift that produces is higher than the timing reference clock CLKB that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter 201b to begin to count up to second counts according to the second above-mentioned counts, so what well imagine is, this second counts must be greater than the first above-mentioned counts, can it for example be 1100 times for instance, so real-time counter 201b is higher than the timing reference clock CLKB that do not produce frequency drift according to this after beginning to count up to above-mentioned second counts of giving an example (that is 900 times), 1 second the fixed count time that promptly can obtain.

In addition, as low-power oscillator 201a when the timing reference clock CLKB of the frequency drift that produces is lower than the timing reference clock CLKB that does not produce frequency drift instantly, this moment is if real-time counter 201b is lower than the timing reference clock CLKB that do not produce frequency drift according to this after beginning to count up to above-mentioned first counts of giving an example (that is 1000 times), what well imagine is that the resulting fixed count time of real-time counter 201b can be greater than 1 second.

So compensating unit 213 this moment then can according to search unit 211 in built-in look-up table, find out the voltage detector 209 low-power oscillator 201a that detects operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply, whether produce frequency drift and judge the timing reference clock CLKB that low-power oscillator 201a supplied instantly, and as low-power oscillator 201a when the timing reference clock CLKB of the frequency drift that produces is lower than the timing reference clock CLKB that does not produce frequency drift instantly, obtain the above-mentioned fixed count time after causing real-time counter 201b to begin to count up to the 3rd counts according to the 3rd above-mentioned counts, so what well imagine is, this the 3rd counts must be less than the first above-mentioned counts, can it for example be 900 times for instance, so real-time counter 201b is lower than the timing reference clock CLKB that do not produce frequency drift according to this after beginning to count up to above-mentioned the 3rd counts of giving an example (that is 1100 times), 1 second the fixed count time that promptly can obtain.

In addition, when moisture detector 205 or Temperature Detector 207 receive real-time counter 201b behind the detection signal DS that regularly produces, the operation workflow of RTC IC 201 inner body and voltage detector 209 receive real-time counter 201b behind the detection signal DS that regularly produces, the overall operation flow process of the inside of RTC IC 201 is similar, so also no longer given unnecessary details it at this.

In the present embodiment, because when voltage detector 209 receive real-time counter 201b behind the detection signal DS that regularly produces, just can detect the Vosc of operating voltage instantly of low-power oscillator 201a, so will elongate the time, the consumed power of voltage detector 209 can be averaged in to almost negligible stage.And in another embodiment of the present invention, voltage detector 209 is not restricted to be embedded among the RTCIC 201, that is to say, voltage detector 209 can be configured in outside the RTC IC 201 as moisture detector 205 and Temperature Detector 207, so the practice not only can reach the technology effect that the present invention desires to reach, and more can allow the design complexities of RTC IC 201 and cost of manufacture reduce.

And it will be further appreciated that, the foregoing description search the characteristic that unit 211 can have programmable, become thereby change built-in look-up table to reach whenever and wherever possible environment according to RTC IC 201 at normal temperature or very under the temperature state, low-power oscillator 201a operating voltage Vosc instantly, when lower operating temps and operational humidity instantly the characteristic parameter value of most bars of the timing reference clock CLKB that does not produce this frequency drift that should supply.

Fig. 4 shows electronic installation 400 calcspars according to another preferred embodiment of the present invention.Please refer to Fig. 4, the electronic installation 400 of present embodiment for example can be videocorder, sound equipment, personal computer, mobile phone, MP3, PDA, camera ... etc., but and be subject to this, and it comprises real-time clock integrated circuit (RealTime Clock Integrated Circuit, be called for short RTC IC) 401, electronic apparatus system 403, Temperature Detector 405, and moisture detector 407.Wherein, RTC IC 401 is used to supply when correct gate time is in machine open/close for electronic installation 400 and uses.

In the present embodiment, RTC IC 401 comprises adjustable low-power oscillator 401a, real-time counter 401b, control unit 401c, and interface bus 401d.Wherein, adjustable low-power oscillator 401a can select ring oscillator (ring oscillator), RC oscillator (RC oscillator), relaxation oscillator (relaxation oscillator) for use ... wait one of them, but be not limited to this, this adjustable low-power oscillator 401a is used to supply a timing reference clock CLKB, and this timing reference clock CLKB can produce the correspondent frequency drift along with the Vo sc of operating voltage instantly of adjustable low-power oscillator 401a.

The timing reference clock CLKB that does not produce frequency drift that real-time counter 401b is supplied according to first counts and adjustable low-power oscillator 401a, and obtain a fixed count time after beginning to count up to first counts, and regularly (for example be per 30 seconds, but be not limited to this) produces a detection signal DS.For instance: at first, suppose that the first above-mentioned counts is 1000 times, when then real-time counter 401b begins to count the timing reference clock that does not produce frequency drift that adjustable low-power oscillator 401a supplied CLKB to 1000 time, for example can obtain 1 second fixed count time.

Control unit 401c couples adjustable low-power oscillator 401a and real-time counter 401b, this control unit 401c be used for every reception real-time counter 401b behind the detection signal DS that regularly produces, then begin to detect the Vosc of operating voltage instantly of adjustable low-power oscillator 401a, and from a look-up table, find out according to this adjustable low-power oscillator 401a this instantly operating voltage Vosc the timing reference clock CLKB that does not produce frequency drift that should supply, and then judge the timing reference clock CLKB that adjustable low-power oscillator 401a supplied instantly and whether produce frequency drift, wherein, when the timing reference clock CLKB that is supplied instantly as adjustable low-power oscillator 401a produces frequency drift, control unit 401c can be corresponding the generation first control signal CS1 or the second control signal CS2 with the timing reference clock CLKB that causes adjustable low-power oscillator 401a to be supplied instantly be adjustable low-power oscillator 401a operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply, and obtain the above-mentioned fixed count time after making real-time counter 401b begin to count up to the first above-mentioned counts according to this.

In the present embodiment, control unit 401c comprises voltage detector 409 and searches unit 411.Wherein, voltage detector 409 couples adjustable low-power oscillator 401a and real-time counter 401b, after this voltage detector 409 is used for detection signal DS that every reception real-time counter 401b regularly produced, then begin to detect the Vosc of operating voltage instantly of adjustable low-power oscillator 401a.Search unit 411 and couple voltage detector 409 and adjustable low-power oscillator 401a and built-in above-mentioned look-up table, this search unit 411 be used for built-in look-up table find out the voltage detector 409 adjustable low-power oscillator 401a that detects operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply, and the corresponding according to this above-mentioned first control signal CS1 or the second control signal CS2 of generation.

Interface bus 401d couples and searches unit 411 and real-time counter 401b, and 403 pairs of the electronic apparatus systems that this interface bus 401d is used for being had according to the serial transmission protocol of standard microprocessor 403a search unit 411 and real-time counter 401b carries out synchronous or asynchronous setting.Wherein, this interface bus 401d for example can be internal integrated circuit (inner integrated circuit, I ²C) bus, serial peripheral interface (serial peripheral interface, SPI) bus, little line interface (microwireinterface) bus or control area net network (controller area network bus, CAN) bus ... etc., but be not limited to this.

Temperature Detector 407 couples adjustable low-power oscillator 401a and real-time counter 401b, this Temperature Detector 407 be used for every reception real-time counter 401b behind the detection signal DS that regularly produces, then begin to detect the lower operating temps of working as of adjustable low-power oscillator 401a.Moisture detector 409 couples adjustable low-power oscillator 401a and real-time counter 401b, this moisture detector 409 be used for every reception real-time counter 401b behind the detection signal DS that regularly produces, then begin to detect the operational humidity instantly of adjustable low-power oscillator 401a.

Searching unit 411 built-in look-up tables at present embodiment is writing down disclosed at normal temperature or very under the temperature state as similar Fig. 3, adjustable low-power oscillator 401a is at operating voltage Vosc instantly, when lower operating temps and operational humidity instantly most bar characteristic curves of the timing reference clock CLKB that does not produce this frequency drift that should supply, and search the characteristic that unit 411 similarly can have programmable, become thereby change built-in look-up table at normal temperature or very under the temperature state to reach whenever and wherever possible environment according to RTC IC 401, low-power oscillator 401a is at operating voltage Vosc instantly, when lower operating temps and operational humidity instantly the characteristic parameter value of most bars of the timing reference clock CLKB that does not produce this frequency drift that should supply.

Fig. 5 shows the circuit diagram of the adjustable low-power oscillator 401a internal circuit of present embodiment.Please refer to Fig. 5, adjustable low-power oscillator 401a comprises first switch SW 1, second switch SW2, the first inverter INV1, the second inverter INV2, the 3rd inverter INV3, the 4th inverter INV4, and the 5th inverter INV5.Wherein, first switch SW 1 couples with second switch SW2 and searches unit 411, and the control end of this first switch SW 1 and the control end of second switch SW2 are used for the first above-mentioned control signal CS1 of corresponding reception or the second control signal CS2 and whether determine conducting.

First end of first switch SW 1 couples second end of second switch SW2, the input of the first inverter INV1 and the output of the 5th inverter INV5, second end of first switch SW 1 couples the output of the second inverter INV2 and the input of the 3rd inverter INV3, and first end of second switch SW2 couples the input of the 4th inverter INV4 and the output of the 3rd inverter INV3, with output timing reference clock CLKB.The output of the first inverter INV1 couples the input of the second inverter INV2, and the output of the 4th inverter INV4 couples the input of the 5th inverter INV5.

In the present embodiment, if when desire reduces the frequency of the timing reference clock CLKB that adjustable low-power oscillator 401a supplied, then can increase the serial connection number of adjustable low-power oscillator 401a internal inverters INV1-INV5; And, then can reduce the serial connection number of adjustable low-power oscillator 401a internal inverters INV1-INV5 when if desire increases the frequency of the timing reference clock CLKB that adjustable low-power oscillator 401a supplied.In addition, if when desiring more to reduce the frequency of the timing reference clock CLKB that adjustable low-power oscillator 401a supplied, then can be between inner number that increases switch (not illustrating) of adjustable low-power oscillator 401a and two ends thereof the serial connection number of inverter, or the increase inverter is connected in series number between first end of first switch SW 1 and second end and between first end of second switch SW2 and second end.

And after following content will receive the detection signal DS of real-time counter 401b institute timing generation with voltage detector 409 earlier, the overall operation flow process of the inside of RTC IC 401 illustrated.

According to above-mentioned, when voltage detector 409 receive real-time counter 401b behind the detection signal DS that regularly produces, just can begin to detect the Vosc of operating voltage instantly of adjustable low-power oscillator 401a, and search this moment unit 411 can in built-in look-up table, find out the voltage detector 409 adjustable low-power oscillator 401a that detects operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply.

What deserves to be mentioned is again, the accuracy of its timing reference clock CLKB that provides because being subjected to the change of operating voltage Vosc easily, adjustable low-power oscillator 401a is provided, so as adjustable low-power oscillator 401a when the timing reference clock CLKB of the frequency drift that produces is higher or lower than the timing reference clock CLKB that does not produce frequency drift instantly, this moment is if real-time counter 401b is higher than the timing reference clock CLKB that do not produce frequency drift according to this after beginning to count up to above-mentioned first counts of giving an example (that is 1000 times), what well imagine is, the resulting fixed count time of real-time counter 401b can less than or greater than 1 second.

So search unit 411 this moment can according to find out in the built-in look-up table voltage detector 409 adjustable low-power oscillator 401a that detects operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply, and the corresponding according to this above-mentioned first control signal CS1 or the control end of second control signal CS2 to the first switch SW 1 and the control end of second switch SW2 of generation, so to change the serial connection number of adjustable low-power oscillator 401a internal inverters INV1-INV5, and then the timing reference clock CLKB that makes adjustable low-power oscillator 401a be supplied instantly be adjustable low-power oscillator 401a operating voltage Vosc instantly the timing reference clock CLKB that does not produce frequency drift that should supply, and obtain the above-mentioned fixed count time after making real-time counter 401b begin to count up to the first above-mentioned counts according to this.

In addition, when moisture detector 405 or Temperature Detector 407 receive real-time counter 401b behind the detection signal DS that regularly produces, the operation workflow of RTC IC 401 inner body and voltage detector 409 receive real-time counter 401b behind the detection signal DS that regularly produces, the overall operation flow process of the inside of RTC IC 401 is similar, so also no longer given unnecessary details it at this.

In the present embodiment, because when voltage detector 409 receive real-time counter 401b behind the detection signal DS that regularly produces, just can detect the Vosc of operating voltage instantly of adjustable low-power oscillator 401a, so will elongate the time, the consumed power of voltage detector 409 can be averaged in to almost negligible stage.And in another embodiment of the present invention, voltage detector 409 is not restricted to be embedded among the RTC IC 401, that is to say, voltage detector 409 can be configured in outside the RTC IC 401 as moisture detector 405 and Temperature Detector 407, so the practice not only can reach the technology effect that the present invention desires to reach, and more can allow the design complexities of RTC IC 401 and cost of manufacture reduce.

In sum, the present invention provides a kind of real-time clock integrated circuit and uses the electronic installation of this real-time clock integrated circuit.According to spirit of the present invention, because real-time clock integrated circuit provided by the present invention by with low-power oscillator under the temperature state of normal temperature/very, it is operating voltage instantly, most bar characteristic curves of the timing reference clock that does not produce frequency drift that should supply when lower operating temps and the institute of operational humidity are instantly noted down in look-up table, and the voltage detector of arranging in pairs or groups simultaneously, Temperature Detector and moisture detector detect the operating voltage instantly of low-power oscillator, when lower operating temps and operational humidity instantly, so carry out the compensation that low-power oscillator produces the timing reference clock of frequency drift in the mode of tabling look-up again.Therefore, real-time clock integrated circuit provided by the present invention not only can reach consumed power, cost of manufacture and the design complexities that reduces real-time clock integrated circuit integral body simultaneously, and the time that more can allow real-time clock integrated circuit carry out the timing running is elongated.

Though the present invention discloses as above with preferred embodiment; so it is not to be used to limit the present invention; anyly have the knack of this skill person; without departing from the spirit and scope of the present invention; when can doing a little change and retouching, so protection scope of the present invention is as the criterion when looking the claim person of defining of the present invention.

Claims

1. real-time clock integrated circuit comprises:

One low-power oscillator is used to supply a timing reference clock, and wherein, this timing reference clock is along with an operating voltage and produce a corresponding frequency drift instantly of this low-power oscillator;

One real-time counter does not obtain a fixed count time with producing this timing reference clock of this frequency drift after beginning to count up to this first counts according to one first counts, and regularly produces a detection signal; And

One control unit comprises:

One voltage detector couples this low-power oscillator and this real-time counter, and what be used for beginning behind this detection signal of every reception detecting this low-power oscillator should descend operating voltage;

One searches the unit, couples this voltage detector and a built-in look-up table, be used for this look-up table find out this voltage detector detect this low-power oscillator should descend operating voltage this timing reference clock that does not produce this frequency drift that should supply; And

One compensating unit, couple this and search the unit, this low-power oscillator and this real-time counter, according to this low-power oscillator should descend operating voltage this timing reference clock that does not produce this frequency drift that should supply, whether produce this frequency drift and judge this timing reference clock that this low-power oscillator supplied instantly, wherein, when this timing reference clock of being supplied instantly when this low-power oscillator produced this frequency drift, this compensating unit caused this real-time counter to obtain this fixed count time according to one second counts or one the 3rd counts after beginning to count up to this second counts or the 3rd counts.

2. real-time clock integrated circuit as claimed in claim 1, wherein, when this timing reference clock that produces this frequency drift is higher than this timing reference clock that does not produce this frequency drift, this compensating unit obtains this fixed count time after causing this real-time counter to begin to count up to this second counts according to this second counts, and when this timing reference clock that produces this frequency drift is lower than this timing reference clock that does not produce this frequency drift, this compensating unit obtains this fixed count time after causing this real-time counter to begin to count up to the 3rd counts according to the 3rd counts, wherein this second counts is greater than this first counts, and the 3rd counts is less than this first counts.

3. real-time clock integrated circuit as claimed in claim 2, more comprise an interface bus, couple this and search unit, this compensating unit and this real-time counter, an electronic apparatus system that is used for being had according to a serial host-host protocol of standard a microprocessor is searched unit, this compensating unit and this real-time counter to this and is carried out synchronous or asynchronous setting.

4. real-time clock integrated circuit as claimed in claim 3, wherein, this interface bus comprises an internal integrate circuit bus, a serial peripheral interface bus, a little line interface bus or a control area net network bus.

5. real-time clock integrated circuit as claimed in claim 1, wherein, this look-up table is being noted down at a normal temperature or one very under the temperature state, this low-power oscillator should descend operating voltage a characteristic curve of this timing reference clock that does not produce this frequency drift that should supply.

6. real-time clock integrated circuit as claimed in claim 1, wherein, this low-power oscillator comprises a ring oscillator, a RC oscillator or a relaxation oscillator.

7. real-time clock integrated circuit comprises:

One adjustable low-power oscillator is used to supply a timing reference clock, and wherein, this timing reference clock is along with an operating voltage and produce a corresponding frequency drift instantly of this adjustable low-power oscillator;

One real-time counter couples this adjustable low-power oscillator, does not obtain a fixed count time with producing this timing reference clock of this frequency drift after beginning to count up to this first counts according to one first counts, and regularly produces a detection signal; And

One control unit, couple this adjustable low-power oscillator and this real-time counter, what be used for beginning behind this detection signal of every reception detecting this adjustable low-power oscillator should descend operating voltage, and from a look-up table, find out in view of the above this adjustable low-power oscillator should descend operating voltage this timing reference clock that does not produce this frequency drift that should supply, whether produce this frequency drift and judge this timing reference clock that this adjustable low-power oscillator supplied instantly, wherein, when this timing reference clock of being supplied instantly when this adjustable low-power oscillator produces this frequency drift, generation one first control signal or one second control signal of this control unit correspondence, with cause this timing reference clock that this adjustable low-power oscillator supplied instantly for this adjustable low-power oscillator should descend operating voltage this timing reference clock that does not produce this frequency drift that should supply, and obtain this fixed count time after making this real-time counter begin to count up to this first counts in view of the above.

8. real-time clock integrated circuit as claimed in claim 7, wherein, this control unit comprises:

One voltage detector couples this adjustable low-power oscillator and this real-time counter, and what be used for beginning behind this detection signal of every reception detecting this adjustable low-power oscillator should descend operating voltage; And

One searches the unit, couple this voltage detector and this adjustable low-power oscillator and built-in this look-up table, be used for this look-up table find out this voltage detector detect this adjustable low-power oscillator should descend operating voltage this timing reference clock that does not produce this frequency drift that should supply, and corresponding in view of the above those control signals of generation.

9. real-time clock integrated circuit as claimed in claim 8, more comprise an interface bus, couple this and search unit and this real-time counter, this is searched the unit to an electronic apparatus system that is used for being had according to a serial host-host protocol of standard a microprocessor and this real-time counter carries out synchronous or asynchronous setting.

10. real-time clock integrated circuit as claimed in claim 9, wherein, this interface bus comprises an internal integrate circuit bus, a serial peripheral interface bus, a little line interface bus or a control area net network bus.

11. real-time clock integrated circuit as claimed in claim 7, wherein, this adjustable low-power oscillator comprises:

One first switch couples this and searches the unit, and this first switch has one first end, one second end and a control end, and wherein, this control end of this first switch is used for corresponding this first control signal of reception or this second control signal and whether determines its conducting;

One first inverter has an input and an output, and wherein, this input of this first inverter couples this first end of this first switch;

One second inverter has an input and an output, and wherein, this input of this second inverter couples this output of this first inverter, and this output of this second inverter then couples this second end of this first switch; And

One the 3rd inverter has an input and an output, and wherein, this input of the 3rd inverter couples this output of this second inverter, and this output of the 3rd inverter then couples this input of this first inverter.

12. real-time clock integrated circuit as claimed in claim 11, wherein, this adjustable low-power oscillator more comprises:

One second switch, couple this and search the unit, this second switch has one first end, one second end and a control end, wherein, this control end of this second switch be used for corresponding this first control signal of reception or this second control signal and whether determine its conducting, this first end of this second switch couples this output of the 3rd inverter, this of this second switch second end then couples this first end of this first switch;

One the 4th inverter has an input and an output, and wherein this input of the 4th inverter couples this first end of this second switch; And

One the 5th inverter has an input and an output, and wherein, this input of the 5th inverter couples this output of the 4th inverter, and this output of the 5th inverter then couples this input of this first inverter.

13. real-time clock integrated circuit as claimed in claim 7, wherein, this look-up table is being noted down at a normal temperature or one very under the temperature state, this adjustable low-power oscillator should descend operating voltage a characteristic curve of this timing reference clock that does not produce this frequency drift that should supply.

14. real-time clock integrated circuit as claimed in claim 7, wherein, this adjustable low-power oscillator comprises a ring oscillator, a RC oscillator or a relaxation oscillator.

15. an electronic installation comprises:

One real-time clock integrated circuit comprises:

One low-power oscillator is used to supply a timing reference clock, wherein, this timing reference clock along with this low-power oscillator one instantly operating voltage, when lower operating temps or an operational humidity and produce a corresponding frequency drift instantly;

One real-time counter does not obtain a fixed count time with producing this timing reference clock of this frequency drift after beginning to count up to this first counts according to one first counts, and regularly produces a detection signal;

One control unit;

One Temperature Detector couples this low-power oscillator and this real-time counter, is used for beginning to detect behind this detection signal of every reception the lower operating temps that deserves of this low-power oscillator; And

One moisture detector couples this low-power oscillator and this real-time counter, and what be used for beginning behind this detection signal of every reception detecting this low-power oscillator should descend operational humidity;

Wherein this control unit comprises:

One searches the unit, couple this voltage detector, this Temperature Detector and this moisture detector and a built-in look-up table, be used for this look-up table find out this voltage detector, this Temperature Detector or this moisture detector detect this low-power oscillator should descend operating voltage, should lower operating temps maybe should descend operational humidity this timing reference clock that does not produce this frequency drift that should supply; And

One compensating unit, couple this and search the unit, this low-power oscillator and this real-time counter, should descend operating voltage according to this low-power oscillator, deserve lower operating temps maybe should descend operational humidity this timing reference clock that does not produce this frequency drift that should supply, whether produce this frequency drift and judge this timing reference clock that this low-power oscillator supplied instantly, wherein, when this timing reference clock of being supplied instantly when this low-power oscillator produced this frequency drift, this compensating unit caused this real-time counter to obtain this fixed count time according to one second counts or one the 3rd counts after beginning to count up to this second counts or the 3rd counts.

16. electronic installation as claimed in claim 15, wherein when this timing reference clock that produces this frequency drift is higher than this timing reference clock that does not produce this frequency drift, this compensating unit obtains this fixed count time after causing this real-time counter to begin to count up to this second counts according to this second counts, and when this timing reference clock that produces this frequency drift is lower than this timing reference clock that does not produce this frequency drift, this compensating unit obtains this fixed count time after causing this real-time counter to begin to count up to the 3rd counts according to the 3rd counts, wherein, this second counts is greater than this first counts, and the 3rd counts is less than this first counts.

17. electronic installation as claimed in claim 16, wherein, this real-time clock integrated circuit more comprises an interface bus, couple this and search unit, this compensating unit and this real-time counter, an electronic apparatus system that is used for being had according to a serial host-host protocol of standard a microprocessor is searched unit, this compensating unit and this real-time counter to this and is carried out synchronous or asynchronous setting.

18. electronic installation as claimed in claim 17, wherein, this interface bus comprises an internal integrate circuit bus, a serial peripheral interface bus, a little line interface bus or a control area net network bus.

19. electronic installation as claimed in claim 15, wherein, this look-up table is being noted down at a normal temperature or one very under the temperature state, this low-power oscillator should descend operating voltage, deserve lower operating temps with should descend operational humidity many characteristic curves of this timing reference clock that does not produce this frequency drift that should supply.

20. electronic installation as claimed in claim 15, wherein, this low-power oscillator comprises a ring oscillator, a RC oscillator or a relaxation oscillator.

21. an electronic installation comprises:

One real-time clock integrated circuit comprises:

One control unit;

One moisture detector couples this low-power oscillator and this real-time counter, and what be used for beginning behind this detection signal of every reception detecting this low-power oscillator should descend operational humidity,

Wherein this control unit comprises:

22. electronic installation as claimed in claim 21, wherein when this timing reference clock that produces this frequency drift is higher than this timing reference clock that does not produce this frequency drift, this compensating unit obtains this fixed count time after causing this real-time counter to begin to count up to this second counts according to this second counts, and when this timing reference clock that produces this frequency drift is lower than this timing reference clock that does not produce this frequency drift, this compensating unit obtains this fixed count time after causing this real-time counter to begin to count up to the 3rd counts according to the 3rd counts, wherein this second counts is greater than this first counts, and the 3rd counts is less than this first counts.

23. electronic installation as claimed in claim 22, wherein, this real-time clock integrated circuit more comprises an interface bus, couple this and search unit, this compensating unit and this real-time counter, an electronic apparatus system that is used for being had according to a serial host-host protocol of standard a microprocessor is searched unit, this compensating unit and this real-time counter to this and is carried out synchronous or asynchronous setting.

24. electronic installation as claimed in claim 23, wherein, this interface bus comprises an internal integrate circuit bus, a serial peripheral interface bus, a little line interface bus or a control area net network bus.

25. electronic installation as claimed in claim 21, wherein, the record of this look-up table sees at a normal temperature or one very under the temperature state, this low-power oscillator should descend operating voltage, deserve lower operating temps with should descend operational humidity many characteristic curves of this timing reference clock that does not produce this frequency drift that should supply.

26. electronic installation as claimed in claim 21, wherein, this low-power oscillator comprises a ring oscillator, a RC oscillator or a relaxation oscillator.

27. an electronic installation comprises:

Real-time clock integrated circuit comprises:

One adjustable low-power oscillator is used to supply a timing reference clock, wherein, this timing reference clock along with this adjustable low-power oscillator one instantly operating voltage, when lower operating temps or an operational humidity and produce a corresponding frequency drift instantly;

One control unit, couple this adjustable low-power oscillator and this real-time counter, be used for causing behind this detection signal of every reception detect this adjustable low-power oscillator should descend operating voltage, deserve lower operating temps and maybe should descend operational humidity, and from a look-up table, find out in view of the above this adjustable low-power oscillator should descend operating voltage this timing reference clock that does not produce this frequency drift that should supply, whether produce this frequency drift and judge this timing reference clock that this adjustable low-power oscillator supplied instantly, wherein, when this timing reference clock of being supplied instantly when this adjustable low-power oscillator produces this frequency drift, generation one first control signal or one second control signal of this control unit correspondence, with cause this timing reference clock that this adjustable low-power oscillator supplied instantly for this adjustable low-power oscillator should descend operating voltage this timing reference clock that does not produce this frequency drift that should supply, and obtain this fixed count time after making this real-time counter begin to count up to this first counts in view of the above.

28. electronic installation as claimed in claim 27 more comprises:

One Temperature Detector couples this adjustable low-power oscillator and this real-time counter, is used for beginning to detect behind this detection signal of every reception the lower operating temps that deserves of this adjustable low-power oscillator; And

One moisture detector couples this adjustable low-power oscillator and this real-time counter, and what be used for beginning behind this detection signal of every reception detecting this adjustable low-power oscillator should descend operational humidity.

29. electronic installation as claimed in claim 28, wherein, this control unit comprises:

One searches the unit, couple this voltage detector, this Temperature Detector, this moisture detector and this adjustable low-power oscillator and built-in this look-up table, be used for finding out this voltage detector, this Temperature Detector or this moisture detector and detect this adjustable low-power oscillator and should descend operating voltage, deserve this timing reference clock that does not produce this frequency drift that lower operating temps maybe should descend operational humidity institute to supply at this look-up table, and this first control signal of generation or this second control signal of correspondence in view of the above.

30. electronic installation as claimed in claim 29, wherein, this real-time clock integrated circuit more comprises an interface bus, couple this and search unit and this real-time counter, this is searched the unit to an electronic apparatus system that is used for being had according to a serial host-host protocol of standard a microprocessor and this real-time counter carries out synchronous or asynchronous setting.

31. electronic installation as claimed in claim 30, wherein, this interface bus comprises an internal integrate circuit bus, a serial peripheral interface bus, a little line interface bus or a control area net network bus.

32. electronic installation as claimed in claim 27, wherein, this adjustable low-power oscillator comprises:

One first switch couples this and searches the unit, and this first switch has one first end, one second end and a control end, and wherein, this control end of this first switch is used for corresponding this first control signal of reception or second control signal and whether determines its conducting;

33. electronic installation as claimed in claim 32, wherein, this adjustable low-power oscillator more comprises:

One the 4th inverter has an input and an output, and wherein, this input of the 4th inverter couples this first end of this second switch; And

34. electronic installation as claimed in claim 27, wherein, this look-up table is being noted down at a normal temperature or one very under the temperature state, this adjustable low-power oscillator should descend operating voltage, deserve lower operating temps with should descend operational humidity many characteristic curves of this timing reference clock that does not produce this frequency drift that should supply.

35. electronic installation as claimed in claim 27, wherein, this adjustable low-power oscillator comprises a ring oscillator, a RC oscillator or a relaxation oscillator.

36. an electronic installation comprises:

Real-time clock integrated circuit comprises:

One real-time counter, couple this adjustable low-power oscillator, do not obtain a fixed count time with producing this timing reference clock of this frequency drift after beginning to count up to this first counts according to one first counts, and regularly produce a detection signal, detect should descending operating voltage, deserving lower operating temps and maybe should descend operational humidity of this adjustable low-power oscillator to cause; And

One control unit, couple this adjustable low-power oscillator and this real-time counter, according to this adjustable low-power oscillator should descend operating voltage, deserving lower operating temps maybe should descend operational humidity and find out this adjustable low-power oscillator and should descend operating voltage from a look-up table, deserve lower operating temps maybe should descend operational humidity this timing reference clock that does not produce this frequency drift that should supply, whether produce this frequency drift to judge this timing reference clock that this adjustable low-power oscillator supplied instantly, when wherein this timing reference clock of being supplied instantly when this adjustable low-power oscillator produces this frequency drift, generation one first control signal of this control unit correspondence or one second control signal with this timing reference clock of causing this adjustable low-power oscillator and being supplied instantly for this adjustable low-power oscillator should descend operating voltage this timing reference clock that does not produce this frequency drift that should supply, and obtain this fixed count time after making this real-time counter begin to count up to this first counts in view of the above.

37. electronic installation as claimed in claim 36 more comprises:

One voltage detector couples this adjustable low-power oscillator and this real-time counter, and what be used for beginning behind this detection signal of every reception detecting this adjustable low-power oscillator should descend operating voltage;

38. electronic installation as claimed in claim 37, wherein, this control unit comprises:

39. electronic installation as claimed in claim 38, wherein, this real-time clock integrated circuit more comprises an interface bus, couple this and search unit and this real-time counter, this is searched the unit to an electronic apparatus system that is used for being had according to a serial host-host protocol of standard a microprocessor and this real-time counter carries out synchronous or asynchronous setting.

40. electronic installation as claimed in claim 39, wherein, this interface bus comprises an internal integrate circuit bus, a serial peripheral interface bus, a little line interface bus or a control area net network bus.

41. electronic installation as claimed in claim 36, wherein, this adjustable low-power oscillator comprises:

42. electronic installation as claimed in claim 41, wherein, this adjustable low-power oscillator more comprises:

43. electronic installation as claimed in claim 36, wherein, this look-up table is being noted down at a normal temperature or one very under the temperature state, this adjustable low-power oscillator should descend operating voltage, deserve lower operating temps with should descend operational humidity many characteristic curves of this timing reference clock that does not produce this frequency drift that should supply.

44. electronic installation as claimed in claim 36, wherein, this adjustable low-power oscillator comprises a ring oscillator, a RC oscillator or a relaxation oscillator.