CN2278964Y - Device capable of instantaneously detecting abnormal volatage in microcontroller - Google Patents

Abstract

The utility model relates to a device which can instantaneously detect the abnormal voltage in a microcontroller, which is characterized in that the utility model comprises a detecting circuit and a locking circuit. The detecting voltage value of the detecting circuit can be set. The detecting circuit is of a logic switch. The power supply connection terminal of the logic switch is connected to the voltage reset terminal of the inner circuit of the microcontroller. The input terminal of the logic switch is connected to the power terminal of the inner circuit of the microcontroller. The output terminal of the logic switch is connected to the input terminal correspondingly acted by the locking circuit. The flag note signal of the abnormal voltage can be output from the output terminal of the locking circuit. The off-rating short-term fluctuation of the voltage in the microcontroller can be sensitively detected and can be locked by the signal. Abnormal voltage telecommunication can be sent out by the flag note signal of the output terminal of the locking circuit. Treatments with the functions of interruption, resetting, etc. can be provided.

Description

Moment detects abnormal voltage device in the microcontroller

But the utility model is the device that relevant a kind of moment detects abnormal voltage in the microcontroller, particularly a kind ofly with digital circuit voltage in the microcontroller is carried out moment and detect, instantaneous variation with the voltage off-rating, detected and transmitted the abnormal voltage telecommunication, act on interruption is provided or reset etc. and handling.

Traditional microcontroller, can only be in some supply voltage scope, the ability operate as normal, in case supply voltage exceeds outside the normal range, the situation that then can cause the microcontroller malfunction, therefore, recently supply voltage is in the protection design that causes the controller malfunction, must make the supply voltage that exceeds normal range of operation that microprocessor is stayed in off position (Reset state), after supply voltage enters normal range of operation, just restart microcontroller and start working, thus there is its necessity voltage check device to be set in the microcontroller periphery, with the screening supply voltage.

With regard to general design voltage pick-up unit, as shown in Figure 1, it is the voltage-level detector that constitutes with comparator circuit, yet, because it is circuit structure relatively, can't cooperate the design system that needs electricity-saving function, make general microcontroller not adopt this kind frame mode to implement, and as Fig. 2 or shown in Figure 3, the Reset pin of reseting of establishing an outside in microcontroller uses to the user, though conformed with the design system demand that can incorporate electricity-saving function in the design, yet the external circuit of this kind structure Reset pin is again low-pass filtering (the RC low pass filter) structure of a kind of RC, this kind design is found in shown in PCT1996 notification number WO 96/21158 case on July 11, descend the long period in supply voltage, Reset pin voltage is just followed supply voltage and is produced suitable Reset signal, run into the momentary variation situation that supply voltage descends and rises rapidly rapidly from stablizing, still can cause the abnormal situation of microcontroller effect to take place, the destruction that causes acting on inefficacy produces, its voltage check device can't detect the abnormal voltage of moment, SC service ceiling must surpass the minimal reaction time interval in change in voltage, could produce the Reset signal, so these structures are still not satisfactory.

The applicant is that active research is improved because existing microcontroller voltage check device has above-mentioned shortcoming, through some hard production process, and not diligent tireless effort, generation of the present utility model is arranged finally.

Shortcoming at prior art, but the purpose of this utility model is providing a kind of moment to detect the device of abnormal voltage in the microcontroller, utilize the voltage of Reset pin to have the effect of low-pass filter (low pass filter), power supply as this device testing circuit, and not with the voltage source of microcontroller power supply as the utility model device testing circuit, when avoiding descending suddenly because of supply voltage, the comparison point of internal logic circuit is followed supply voltage and is changed, make the moment testing result inaccurate, and be conceived to replace comparator circuit with digital circuit, incomparably, shorten the time span that can detect than the voltage consumption of circuitorder Reset pin.

But a kind of moment detects abnormal voltage device in the microcontroller, it is characterized in that comprising that one sets a testing circuit and a lock-in circuit that detects magnitude of voltage, this testing circuit is a logic switch, the power connector end of this switch is connected to the voltage end of reseting of the interior circuit of this microcontroller, the power end of circuit joins in the input end of this switch and this microcontroller, and the output terminal of this switch is access to the input end of the corresponding effect of this lock-in circuit, flag signal by the output terminal output abnormality voltage of this lock-in circuit, the instantaneous variation of voltage generation off-rating can be detected by sensitivity in the microcontroller, and lock through signal, flag signal in the lock-in circuit output terminal sends the abnormal voltage telecommunication, and interruption is provided or reset etc. acts on handles.

The utility model can be used as stand-alone product and sells to be used the detection at microcontroller.

As for detailed construction of the present utility model, application principle, effect and effect, then the explanation of doing with reference to following adjoint can be understood completely.

Fig. 1 is the existing voltage-level detector synoptic diagram that constitutes with comparator circuit.

Fig. 2 is the existing schematic representation of apparatus that detects abnormal voltage in the microcontroller.

Fig. 3 is the another kind of existing schematic representation of apparatus that detects abnormal voltage in the microcontroller.

Fig. 4 is the logical circuitry of the utility model device.

Fig. 5 is the abnormal voltage detection time voltage pattern of the utility model device.

Fig. 1 to Fig. 3 is the existing circuit diagram that detects the device of abnormal voltage in the microcontroller, by the structure of Fig. 1-3 and above-mentioned existing apparatus as can be known with and shortcoming, do not repeat them here.

Shown in the logical circuitry of Fig. 2, comprise but this kind of the present utility model moment detects the device of abnormal voltage in the microcontroller: one sets the testing circuit 1 and the lock-in circuit 2 that detect magnitude of voltage constitutes.The logic switch 10 of testing circuit 1 is a CMOS preferably, this Switching Power Supply link P1 to the microcontroller to be measured circuit reset (Vres) voltage end, the power end (VDD) of the interior circuit of this switch input terminal P2 and microcontroller to be measured joins.The output terminal of logic switch 10 (PFDO) is access to the input end P3 of lock-in circuit 2 corresponding effects.Lock-in circuit 2 can be the FF flip-flop, or with the locking bolt device (latch) of FF flip-flop equivalent effect.As shown in the figure, with FF flip-flop 11 during as lock-in circuit 2, the CB of FF flip-flop 11 is connected to the output terminal (PFDO) of this logic switch 10, its D end is held with the voltage (Vres) of reseting that power connector end P4 is connected to the interior circuit of above-mentioned microcontroller to be measured jointly, can draw the flag signal (PFF) that detects abnormal voltage in its Q output terminal and R output terminal.These flag signals (PFF) can be connected to and reset circuit (reset μ c), or use triggering and can not protected type interrupt, or only provide this flag signal for user's utilization and judge.Thus, when voltage produces the instantaneous variation of off-rating in microcontroller, can be detected, and after signal locks, send the abnormal voltage telecommunication, interrupt or reset processing such as the effect of grade to provide in the flag signal (PFF) of lock-in circuit 2 output terminals by sensitivity.

Again, the detection current potential of testing circuit 1 can be set in light shield selection (writing) mode (MASKOPTION) with system requirements and be made, and makes its utilization scope can be applicable to various demands.

The utility model is installed on the abnormal voltage generation and does the time spent, the situation of Fig. 5 time voltage pattern for example takes place, voltage/the time curve of the L1 curve representation aforementioned power source end (VDD) among the figure wherein, aforementioned voltage/the time curve of reseting voltage end (Vres) of L2 curve representation, the L3 curve representation is aforementioned resets the voltage/time curve of (RESET), aforementioned logic switch 10 out-put supplies of L4 curve representation lost efficacy and detected signal (Powerfailure detector output, abbreviation PFDO) voltage/time curve, voltage/the time curve of the aforementioned flag signal of L5 curve representation (PFF), in T1 and T2 time power end (VDD) and reset voltage end (Vres), produce moment and long voltage drop respectively.Different with aforementioned existing voltage check device is, in T1 moment, the utility model is installed on the out-put supply inefficacy and detects signal (Power failure detectoroutput), be called for short (PFDO) and flag signal (PFF) and all can detect fine voltage drop, and represent with 1 noble potential, unusual message output is provided, acts on as interrupt or make zero etc. and handling.

From the above as can be known, but this kind of the present utility model moment detects the device of abnormal voltage in the microcontroller, really have and in the digital circuit mode voltage in the microcontroller is carried out moment and detect, transmit the abnormal voltage telecommunication to detect, effect with effect processing such as providing instantaneous interruption or reset, nothing is existing in the digital circuit mode, and voltage instantaneous unusual fluctuation in the microcontroller is changed can't detected shortcoming.

The above is the preferable specific embodiment of the utility model, if comply with the change that conception of the present utility model is done, and when the function of its generation and used technology do not exceed instructions yet and illustrate contained spiritual, all should be in scope of the present utility model.

Claims (5)

1, but a kind of moment detects abnormal voltage device in the microcontroller, it is characterized in that comprising that one sets a testing circuit and a lock-in circuit that detects magnitude of voltage, this testing circuit is a logic switch, the power connector end of this switch is connected to the voltage end of reseting of the interior circuit of this microcontroller, the power end of circuit joins in the input end of this switch and this microcontroller, and the output terminal of this switch is access to the input end of the corresponding effect of this lock-in circuit, flag signal by the output terminal output abnormality voltage of this lock-in circuit, the instantaneous variation of voltage generation off-rating can be detected by sensitivity in the microcontroller, and lock through signal, flag signal in the lock-in circuit output terminal sends the abnormal voltage telecommunication, and interruption is provided or reset etc. acts on handles.

2, but a kind of moment as claimed in claim 1 detects abnormal voltage device in the microcontroller, it is characterized in that wherein this testing circuit is the logic switch of a CMOS formula.

3, but a kind of moment as claimed in claim 1 or 2 detects abnormal voltage device in the microcontroller, it is characterized in that wherein this lock-in circuit is a FF flip-flop, or with the locking bolt device of this FF flip-flop equivalent effect.

4, but a kind of moment as claimed in claim 3 detects abnormal voltage device in the microcontroller, it is characterized in that when with this flip-flop during as lock-in circuit, the CB of this FF flip-flop is connected to the output terminal of this logic switch, its D end and power connector end are connected to the voltage end of reseting of the interior circuit of this microcontroller jointly, can draw the flag signal that detects abnormal voltage in its Q output terminal and R output terminal.

5, but a kind of moment as claimed in claim 3 detects abnormal voltage device in the microcontroller, it is characterized in that wherein the detection current potential of this testing circuit can select the mode of (writing) be set with light shield with system requirements and make.

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