CN202196392U - Watchdog circuit with automatic closing function - Google Patents
Watchdog circuit with automatic closing function Download PDFInfo
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- CN202196392U CN202196392U CN2011202128514U CN201120212851U CN202196392U CN 202196392 U CN202196392 U CN 202196392U CN 2011202128514 U CN2011202128514 U CN 2011202128514U CN 201120212851 U CN201120212851 U CN 201120212851U CN 202196392 U CN202196392 U CN 202196392U
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- triode
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- watchdog
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- 230000010355 oscillation Effects 0.000 claims abstract description 20
- 238000001514 detection method Methods 0.000 claims abstract description 18
- 239000003990 capacitor Substances 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 1
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Abstract
The watchdog circuit with the automatic closing function comprises a watchdog chip, an oscillation module, a counter zero clearing module, a connection module and an external power supply connection module, wherein the oscillation module, the counter zero clearing module, the connection module and the external power supply connection module are connected with the watchdog chip; the external power supply connection module is connected with an overflow pin of the watchdog chip, and the overflow pin outputs high level when the calculator overflows; the external power supply connection module comprises a first resistor connected with the overflow pin, a power supply detection chip for detecting the voltage of an external power supply, and a first diode and a first current-limiting resistor which are connected in series between the first resistor and the output end of the power supply detection chip; the input end of the power supply detection chip is connected with an external power supply; one end of the power supply detection chip is grounded. The utility model has the advantages of rely on detecting external power source, can self-closing watchdog circuit when external power source crosses lowly.
Description
Technical field
The utility model relates to a kind of watchdog circuit with automatic closing function.
Background technology
The application of watchdog circuit circuit; Make single-chip microcomputer can under the unmanned state, realize continuous working; Its principle of work is: an I/O pin of watchdog chip and single-chip microcomputer links to each other, and it periodically sends into high level (or low level) to this I/O pin on this pin of house dog through programmed control, and this program statement is to be placed on other control statements centres of single-chip microcomputer dispersedly; In case single-chip microcomputer is absorbed in a certain program segment behind the program fleet when not getting into the endless loop state owing to disturbing to cause; The program of writing the house dog pin just can not be performed, and in this time, watchdog circuit will be owing to can not get the signal that single-chip microcomputer is sent here; Just it with pin that the single-chip microcomputer reset pin links to each other on see a reset signal off; Single-chip microcomputer is resetted, and promptly program begins to carry out from the reference position of program storage, has so just realized automatically reseting of single-chip microcomputer.
Present watchdog circuit technology mainly contains software watchdog and but its ultimate principle of hardware watchdog all is to utilize the timer conter of zero clearing to realize.Software watchdog utilizes the inner timer conter of single-chip microcomputer to realize, hardware watchdog then utilizes the outside timer conter of single-chip microcomputer to realize.These watchdog circuits all externally power supply cross and close automatically when low.
Summary of the invention
Can't close the shortcoming of watchdog circuit automatically for overcoming prior art, the utility model provides a kind of dependence to detect external power source, cross the watchdog circuit that can close the band automatic closing function of watchdog circuit when low automatically when external power source.
The watchdog circuit of band automatic closing function comprises watchdog chip, the oscillation module that is connected with watchdog chip, counter O reset module, the link block that is connected with single-chip microcomputer and external power source link block;
Described external power source link block is connected with the pin that overflows of watchdog chip, and the described pin that overflows is exported high level when counter overflows;
Described external power source link block comprises with described overflows first resistance that pin is connected, and detects the power supply detection chip of outer power voltage, and is serially connected with first diode and first current-limiting resistance between the output terminal of first resistance and power supply detection chip; The input end of described power supply detection chip is connected with external power source; Described power supply detection chip one end ground connection.
Further; Described link block comprises second triode that base stage is connected with the end away from overflowing pin of first resistance; Be provided with the parallelly connected unit of capacitance-resistance between the base stage of described second triode and the emitter; The collector of described second triode is connected with the single-chip microcomputer resetting pin, is provided with the 3rd electric capacity, the grounded emitter of described second triode between the collector of described second triode and the emitter; Be loaded with first accessory power supply between the collector of described second triode and the emitter, be provided with second current-limiting resistance between the collector of the positive pole of described first accessory power supply and described second triode;
The base stage of described second triode with close the switch module that single-chip microcomputer resets; Described switch module comprises first triode that collector is connected with the base stage of second triode; The base stage of described first triode is connected with the output terminal of second accessory power supply; Be provided with second resistance between the base stage of described first triode and the emitter, the grounded emitter of described first triode; Be provided with the 3rd current-limiting resistance between the base stage of described second accessory power supply and first triode.
Further, described oscillation module comprises first oscillation resistance that is connected with the input end of watchdog chip, and second oscillation resistance that is connected with an output terminal of watchdog chip is with the oscillating capacitance that is connected with another output terminal of watchdog chip; Described first oscillation resistance, second oscillation resistance and oscillating capacitance is parallel with one another is connected.
Further, described counter O reset module comprises the 3rd resistance that is connected with the resetting pin of watchdog chip, the 3rd triode that collector is connected with the resetting pin of watchdog chip and the 4th resistance and the 5th resistance;
Described the 3rd resistance on-load voltage;
The grounded emitter of described the 3rd triode, the base stage of described the 3rd triode is connected with the 4th resistance and the 5th resistance; Be loaded with voltage on described the 4th resistance and the 5th resistance;
The base stage of described the 3rd triode is connected with zero clearing electric capacity with jumper switch, and clear dog pulse is imported described counter O reset module through zero clearing electric capacity, described jumper switch and zero clearing capacitances in series.
The technical conceive of the utility model is: when external power source is lower than 4.6v, think that then external voltage is low excessively, need close the reset function of single-chip microcomputer of watchdog circuit.Its course of work is following, when external power source is crossed when low, if the counter of watchdog chip overflows; By overflowing pin output high level; The level of external power source link block was lower than and overflowed the pin level this moment, first diode current flow, the high level that overflows pin output through first diode, first current-limiting resistance and power supply detection chip to the ground earial drainage; Thereby the base stage level of second triode is dragged down, and second triode ends.And the resetting pin of single-chip microcomputer is that high level is effective, and therefore, single-chip microcomputer can not send reset signal, reaches to close the reset purpose of single-chip microcomputer of watchdog circuit.
Through the switch module that links to each other with link block is set; When needs artificially stop watchdog circuit to reset single-chip microcomputer (like Debugging Program for Single-chip Computer time); The input end and the output terminal of short circuit second accessory power supply, to the base stage input high level of first triode, the first triode conducting and to the emitter earial drainage; Thereby drag down the base stage level of second triode, second triode ends.
In the counter O reset module, when not having clear dog signal, the 3rd triode ends, thereby makes the resetting pin of watchdog chip under normal circumstances be in low level.And counter O reset is that high level is effective.When clear dog signal sends, high level is imported the base stage of the 3rd triode through clear dog electric capacity, jumper switch, the 3rd triode conducting, and to the resetting pin input high level of watchdog chip, the watchdog chip counter is by zero clearing.
The utlity model has and rely on to detect external power source, cross the advantage that to close watchdog circuit when low automatically when external power source.
Description of drawings
Fig. 1 is the circuit diagram of the utility model.
Embodiment
With reference to accompanying drawing, further specify the utility model:
The watchdog circuit of band automatic closing function comprises watchdog chip HEF4060B, the oscillation module that is connected with watchdog chip HEF4060B, counter O reset module, the link block that is connected with single-chip microcomputer and external power source link block;
Described external power source link block is connected with the pin O13 that overflows of watchdog chip HEF4060B, and the described pin O13 that overflows exports high level when counter overflows;
Described external power source link block comprises with described overflows first resistance R 1 that pin O13 is connected; Detect the power supply detection chip S-80146CLMC-JIZ of outer power voltage, and be serially connected with the first diode D1 and the first current-limiting resistance R11 between the output terminal of first resistance R 1 and power supply detection chip S-80146CLMC-JIZ; The input end of described power supply detection chip S-80146CLMC-JIZ is connected with external power source POWER; Described power supply detection chip S-80146CLMC-JIZ one end ground connection.
Described link block comprises the second triode Q2 that base stage is connected with the end away from overflowing pin of first resistance R 1; Be provided with the parallelly connected unit of capacitance-resistance between the base stage of the described second triode Q2 and the emitter; The collector of the described second triode Q2 is connected with single-chip microcomputer resetting pin RESET; Be provided with the 3rd capacitor C 3 between the collector of the described second triode Q2 and the emitter; The grounded emitter of the described second triode Q2 is loaded with first accessory power supply between the collector of the described second triode Q2 and the emitter, be provided with the second current-limiting resistance R7 between the collector of the positive pole of described first accessory power supply and the described second triode Q2;
The base stage of the described second triode Q2 with close the switch module that single-chip microcomputer resets; Described switch module comprises the first triode Q1 that collector is connected with the base stage of the second triode Q2; The base stage of the described first triode Q1 is connected with the output terminal of the second accessory power supply J1; Be provided with second resistance R 2 between the base stage of the described first triode Q1 and the emitter, the grounded emitter of the described first triode Q1; Be provided with the 3rd current-limiting resistance R6 between the base stage of the described second accessory power supply J1 and the first triode Q1.
Described oscillation module comprises the first oscillation resistance R8 that is connected with the input end CIN of watchdog chip HEF4060B; The second oscillation resistance R9 that is connected with an output terminal COUT of watchdog chip is with the oscillating capacitance C4 that is connected with another output terminal COUT of watchdog chip; The described first oscillation resistance R8, the second oscillation resistance R9 are connected with oscillating capacitance C4 is parallel with one another.
Described counter O reset module comprises the 3rd resistance R 3 that is connected with the resetting pin RST of watchdog chip HEF4060B, the 3rd triode Q3 that collector is connected with the resetting pin RST of watchdog chip HEF4060B and the 4th resistance R 4 and the 5th resistance R 10;
Described the 3rd resistance R 3 on-load voltages;
The grounded emitter of described the 3rd triode Q3, the base stage of described the 3rd triode Q3 is connected with the 4th resistance R 4 and the 5th resistance R 10; Be loaded with voltage on described the 4th resistance R 4 and the 5th resistance R 10;
The base stage of described the 3rd triode Q3 is connected with zero clearing capacitor C 5 with jumper switch JWD1, and clear dog pulse CLRWD is through the described counter O reset module of zero clearing capacitor C 5 inputs, and described jumper switch JWD1 connects with zero clearing capacitor C 5.
The technical conceive of the utility model is: when external power source is lower than 4.6v, think that then external voltage is low excessively, need close the reset function of single-chip microcomputer of watchdog circuit.Its course of work is following, when external power source is crossed when low, if the counter of watchdog chip overflows; By overflowing pin output high level; The level of external power source link block was lower than and overflowed the pin level this moment, first diode current flow, the high level that overflows pin output through first diode, first current-limiting resistance and power supply detection chip to the ground earial drainage; Thereby the base stage level of second triode is dragged down, and second triode ends.And the resetting pin of single-chip microcomputer is that high level is effective, and therefore, single-chip microcomputer can not send reset signal, reaches to close the reset purpose of single-chip microcomputer of watchdog circuit.
Through the switch module that links to each other with link block is set; When needs artificially stop watchdog circuit to reset single-chip microcomputer (like Debugging Program for Single-chip Computer time); The input end and the output terminal of short circuit second accessory power supply, to the base stage input high level of first triode, the first triode conducting and to the emitter earial drainage; Thereby drag down the base stage level of second triode, second triode ends.
In the counter O reset module, when not having clear dog signal, the 3rd triode ends, thereby makes the resetting pin of watchdog chip under normal circumstances be in low level.And counter O reset is that high level is effective.When clear dog signal sends, high level is imported the base stage of the 3rd triode through clear dog electric capacity, jumper switch, the 3rd triode conducting, and to the resetting pin input high level of watchdog chip, the watchdog chip counter is by zero clearing.
The utlity model has and rely on to detect external power source, cross the advantage that to close watchdog circuit when low automatically when external power source.
The described content of this instructions embodiment only is enumerating the way of realization of utility model design; The protection domain of the utility model should not be regarded as and only limit to the concrete form that embodiment states, the protection domain of the utility model also reach in those skilled in the art according to the utility model design the equivalent technologies means that can expect.
Claims (4)
1. the watchdog circuit of band automatic closing function is characterized in that: comprise watchdog chip, the oscillation module that is connected with watchdog chip, counter O reset module, the link block that is connected with single-chip microcomputer and external power source link block;
Described external power source link block is connected with the pin that overflows of watchdog chip, and the described pin that overflows is exported high level when counter overflows;
Described external power source link block comprises with described overflows first resistance that pin is connected, and detects the power supply detection chip of outer power voltage, and is serially connected with first diode and first current-limiting resistance between the output terminal of first resistance and power supply detection chip; The input end of described power supply detection chip is connected with external power source; Described power supply detection chip one end ground connection.
2. the watchdog circuit of band automatic closing function as claimed in claim 1; It is characterized in that: described link block comprises second triode that base stage is connected with the end away from overflowing pin of first resistance; Be provided with the parallelly connected unit of capacitance-resistance between the base stage of described second triode and the emitter; The collector of described second triode is connected with the single-chip microcomputer resetting pin; Be provided with the 3rd electric capacity between the collector of described second triode and the emitter; The grounded emitter of described second triode is loaded with first accessory power supply between the collector of described second triode and the emitter, be provided with second current-limiting resistance between the collector of the positive pole of described first accessory power supply and described second triode;
The base stage of described second triode with close the switch module that single-chip microcomputer resets; Described switch module comprises first triode that collector is connected with the base stage of second triode; The base stage of described first triode is connected with the output terminal of second accessory power supply; Be provided with second resistance between the base stage of described first triode and the emitter, the grounded emitter of described first triode; Be provided with the 3rd current-limiting resistance between the base stage of described second accessory power supply and first triode.
3. the watchdog circuit of band automatic closing function as claimed in claim 2; It is characterized in that: described oscillation module comprises first oscillation resistance that is connected with the input end of watchdog chip; Second oscillation resistance that is connected with an output terminal of watchdog chip is with the oscillating capacitance that is connected with another output terminal of watchdog chip; Described first oscillation resistance, second oscillation resistance and oscillating capacitance is parallel with one another is connected.
4. the watchdog circuit of band automatic closing function as claimed in claim 3; It is characterized in that: described counter O reset module comprises the 3rd resistance that is connected with the resetting pin of watchdog chip; The 3rd triode that collector is connected with the resetting pin of watchdog chip and the 4th resistance and the 5th resistance;
Described the 3rd resistance on-load voltage;
The grounded emitter of described the 3rd triode, the base stage of described the 3rd triode is connected with the 4th resistance and the 5th resistance; Be loaded with voltage on described the 4th resistance and the 5th resistance;
The base stage of described the 3rd triode is connected with zero clearing electric capacity with jumper switch, and clear dog pulse is imported described counter O reset module through zero clearing electric capacity, described jumper switch and zero clearing capacitances in series.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202128514U CN202196392U (en) | 2011-06-22 | 2011-06-22 | Watchdog circuit with automatic closing function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202128514U CN202196392U (en) | 2011-06-22 | 2011-06-22 | Watchdog circuit with automatic closing function |
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| Publication Number | Publication Date |
|---|---|
| CN202196392U true CN202196392U (en) | 2012-04-18 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011202128514U Expired - Lifetime CN202196392U (en) | 2011-06-22 | 2011-06-22 | Watchdog circuit with automatic closing function |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202196392U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102339239A (en) * | 2011-06-22 | 2012-02-01 | 杭州炬华科技股份有限公司 | Watchdog circuit with automatic switch-off function |
| CN103713916A (en) * | 2012-10-09 | 2014-04-09 | 华平信息技术股份有限公司 | Automatic application program running method and automatic application program running system in Windows embedded system |
| CN112463426A (en) * | 2020-11-16 | 2021-03-09 | 中国电子科技集团公司第五十八研究所 | Watchdog reset circuit with serial counting function and working method |
-
2011
- 2011-06-22 CN CN2011202128514U patent/CN202196392U/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102339239A (en) * | 2011-06-22 | 2012-02-01 | 杭州炬华科技股份有限公司 | Watchdog circuit with automatic switch-off function |
| CN102339239B (en) * | 2011-06-22 | 2013-06-05 | 杭州炬华科技股份有限公司 | Watchdog circuit with automatic switch-off function |
| CN103713916A (en) * | 2012-10-09 | 2014-04-09 | 华平信息技术股份有限公司 | Automatic application program running method and automatic application program running system in Windows embedded system |
| CN112463426A (en) * | 2020-11-16 | 2021-03-09 | 中国电子科技集团公司第五十八研究所 | Watchdog reset circuit with serial counting function and working method |
| CN112463426B (en) * | 2020-11-16 | 2021-11-16 | 中国电子科技集团公司第五十八研究所 | Watchdog reset circuit with serial counting function and working method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20120418 Effective date of abandoning: 20130605 |
|
| AV01 | Patent right actively abandoned |
Granted publication date: 20120418 Effective date of abandoning: 20130605 |
|
| RGAV | Abandon patent right to avoid regrant |