CN202102054U - Apparatus in multitask one-chip microcomputer system for ensuring accurate measuring of pulse width - Google Patents
Apparatus in multitask one-chip microcomputer system for ensuring accurate measuring of pulse width Download PDFInfo
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- CN202102054U CN202102054U CN2011202202616U CN201120220261U CN202102054U CN 202102054 U CN202102054 U CN 202102054U CN 2011202202616 U CN2011202202616 U CN 2011202202616U CN 201120220261 U CN201120220261 U CN 201120220261U CN 202102054 U CN202102054 U CN 202102054U
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Abstract
Provided is an apparatus in a multitask one-chip microcomputer system for ensuring accurate measuring of pulse width. The apparatus comprises an inverter, a first level transition chip, and a second level transition chip. Signals of one path of the PWM pulse are output to the P0.4 base pin of the microcomputer as the INT0 external interrupt of the one-chip microcomputer system. The signals of the other path of the PWM pulse are output to the input terminal of the inverter, with the output terminal of the inverter connected to the P0.5 base pin of the one-chip microcomputer as INT1 external interrupt of the one-chip microcomputer. The serial port signal UART0 is connected to the P0.1 base pin of the one-chip microcomputer via the first level transition chip as a first serial port input. The serial port signal UART1 is connected to the P0.3 base pin of the one-chip microcomputer via the second level transition chip as a second serial port input. The simulation signal ADC0 is connected to the AIN0.0 base pin of the one-chip microcomputer. The external interrupts INT0 and INT1 are utilized to carry out the task of measuring pulse width. When other tasks are conducted, the interruption service programs of these tasks are utilized to detect whether having experienced the interrupt flag of the external interrupt INT0 or not.
Description
Technical field
The utility model relates to the single-chip microcomputer applied technical field, especially relates to the device that guarantees the pulse width correct measurement in a kind of multitask SCM system.
Background technology
Nowadays, The application of single-chip computer is more and more wider, and wherein 51 series monolithics are single-chip microcomputers of elementary course, also is most widely used a kind of single-chip microcomputer.51 series monolithics are single task work, generally adopt the cooperating type that timeslice controls or adopt the preemptive type of interrupt mode to realize based on the multi-job operation of this single-chip microcomputer, introduce respectively in the face of the measurement of pulse width in this dual mode down:
The cooperating type measure width of controlling with timeslice in the multitask SCM system generally adopts the mode of wait: when the timeslice of measure width arrives, judge that when impulse level was high level, program was waited for; When being low level, first zero clearing timer T0 restarts timer T0 counting (TR0=1), and program is waited for simultaneously.When impulse level becomes high level by low level, stop timer T0 counting (TR0=0).Count value clock ticktack cycle of multiply by timer T0 of timer T0 this moment is pulse width.
The preemptive type of multitask SCM system interrupt mode is to adopt to interrupt carrying out each task, and its measure width realizes with external interrupt INT0 and INT1: the negative edge of pulse is caught by INT0, and the rising edge of next pulse is caught by INT1.First zero clearing timer T0 in the INT0 interrupt service routine; Restart timer T0 and begin counting; In the INT1 interrupt service routine, judge whether timer T0 opens earlier; If open then stop T0 timer counting, the clock ticktack cycle that the count value in this moment T0 timer multiply by timer T0 is pulse width.
But above-mentioned cooperating type realizes that the multi-job operation real-time is poor, and the mcu resource waste is serious, and utilization factor is not high.Though and preemptive type realizes that the multi-job operation real-time is good and the mcu resource utilization factor high; But can clash between interrupting; Especially for the exigent pulse width measuring of real-time in the multitask data acquisition, the pulse width of measuring when clashing can be made mistakes.
The utility model content
The utility model embodiment provides the device that guarantees the pulse width correct measurement in a kind of multitask SCM system, avoids when utilizing preemptive type to realize multi-job operation, and its pulse width measuring task data is made mistakes.
On the one hand; The utility model embodiment provides the device that guarantees the pulse width correct measurement in a kind of multitask SCM system; Said single-chip microcomputer is C8051F020; Comprise: phase inverter, first level transferring chip, second level transferring chip; One road signal of pwm pulse inputs to the INT0 external interrupt of the P0.4 pin of said single-chip microcomputer as said SCM system, and another road signal of pwm pulse inputs to the input end of said phase inverter, and the output terminal of said phase inverter is connected to the ITN1 external interrupt of the P0.5 pin of said single-chip microcomputer as said SCM system; Rs 232 serial interface signal UART0 imports as first serial through the P0.1 pin that said first level transferring chip is connected to said single-chip microcomputer; Rs 232 serial interface signal UART1 imports as second serial through the P0.3 pin that said second level transferring chip is connected to said single-chip microcomputer, and simulating signal ADC0 is connected to the AIN0.0 pin of said single-chip microcomputer, as analog input; Interrupt service routine unit in the said single-chip microcomputer is used for when carrying out serial ports input signal collection and analog input signal acquisition tasks; Detect whether run into the interrupt identification of external interrupt INT0,, then remove the interrupt identification of said external interrupt INT0 if run into the interrupt identification of external interrupt INT0; And detect whether run into the interrupt identification of external interrupt INT1, if run into the interrupt identification of external interrupt INT1, whether the timer T0 that then detects in the single-chip microcomputer starts, if timer T0 starts, then stops timer T0 counting.
Preferably; The utility model embodiment also comprises first build-out resistor that is arranged on the signal reflex that is used for eliminating the serial communication cable on the first serial input end, and second build-out resistor that is arranged on the signal reflex that is used for eliminating the serial communication cable on the second serial input end.
Preferably; The utility model embodiment also comprises the oscillator that is made up of capacitor C 1, C2, quartz crystal G1 and single-chip microcomputer U3, and the two ends of said quartz crystal G1 are connected to the XTAL1 pin and the XTAL2 pin of said single-chip microcomputer respectively and think that said SCM system provides clock.
On the other hand; The utility model embodiment also provides the device that guarantees the pulse width correct measurement in a kind of multitask SCM system; Said single-chip microcomputer is C8051F020, it is characterized in that, comprising: phase inverter, first level transferring chip, second level transferring chip; One road signal of pwm pulse inputs to the INT0 external interrupt of the P0.4 pin of said single-chip microcomputer as said SCM system; Another road signal of pwm pulse inputs to the input end of said phase inverter, and the output terminal of said phase inverter is connected to the INT1 external interrupt of the P0.5 pin of said single-chip microcomputer as said SCM system, and rs 232 serial interface signal UART0 imports as first serial through the P0.1 pin that said first level transferring chip is connected to said single-chip microcomputer; Rs 232 serial interface signal UART1 imports as second serial through the P0.3 pin that said second level transferring chip is connected to said single-chip microcomputer; Simulating signal ADC0 is connected to the AIN0.0 pin of said single-chip microcomputer, and as analog input, the interrupt service routine unit in the said single-chip microcomputer is used for when carrying out serial ports input signal collection and analog input signal acquisition tasks; Detect the interrupt identification that whether runs into external interrupt INT0; If run into the interrupt identification of external interrupt INT0, then first zero clearing timer T0 opening timing device T0 again counts, and removes the interrupt identification of said external interrupt INT0 at last; And detect whether run into the interrupt identification of external interrupt INT1, and if run into the interrupt identification of external interrupt INT1, then detect timer T0 and whether start, if timer T0 starts, then stop timer T0 counting.
Preferably; The utility model embodiment also comprises first build-out resistor that is arranged on the signal reflex that is used for eliminating the serial communication cable on the first serial input end, and second build-out resistor that is arranged on the signal reflex that is used for eliminating the serial communication cable on the second serial input end.
Preferably; The utility model embodiment also comprises the oscillator that is made up of capacitor C 1, C2, quartz crystal G1 and single-chip microcomputer U3, and the two ends of said quartz crystal G1 are connected to the XTAL1 pin and the XTAL2 pin of said single-chip microcomputer respectively and think that said SCM system provides clock.
The utility model embodiment is through introducing the judgement that the pulse-width measuring task starts and stops in the interrupt service routine of serial data collection except that the pulse width measuring task and collection of simulant signal task; And judge according to this and to come control timer T0, thereby guaranteed the correctness of pulse width measuring data in the single-chip microcomputer.
Description of drawings
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art; The accompanying drawing of required use is done to introduce simply in will describing embodiment below; Obviously, the accompanying drawing in describing below only is some embodiment of the utility model, for those of ordinary skills; Under the prerequisite of not paying creative work property, can also obtain other accompanying drawing according to these accompanying drawings.
Guarantee the apparatus structure synoptic diagram of pulse width correct measurement in a kind of multitask SCM system that Fig. 1 provides for the utility model embodiment.
Embodiment
To combine the accompanying drawing among the utility model embodiment below, the technical scheme among the utility model embodiment is carried out clear, intactly description, obviously, described embodiment only is the utility model part embodiment, rather than whole embodiment.Based on the embodiment in the utility model, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of the utility model protection.
Be illustrated in figure 1 as the apparatus structure synoptic diagram that guarantees the pulse width correct measurement in a kind of multitask SCM system that the utility model embodiment provides, single-chip microcomputer is selected C8051F020 for use in the present embodiment.
Visible by Fig. 1; This device comprises: phase inverter D1B, level transferring chip U1, level transferring chip U2; One road signal of pwm pulse inputs to the INT0 external interrupt signal of the P0.4 pin of single-chip microcomputer as SCM system; Another road signal of pwm pulse inputs to the input end 3 of phase inverter D1B, and the output terminal 4 of phase inverter D1B is connected to the ITN1 external interrupt signal of the P0.5 pin of single-chip microcomputer as SCM system.
It is pointed out that in the present embodiment owing to introduced phase inverter D1B, so single-chip microcomputer is when utilizing external interrupt INT0 and INT1 to carry out the pulse width measuring task, only need external interrupt INT0 and INT1 be arranged to negative edge and triggers and get final product.
Rs 232 serial interface signal UART0 imports as first serial through the P0.1 pin that level transferring chip U1 is connected to said single-chip microcomputer.Adopt the MAX485 chip such as, level transferring chip U1, rs 232 serial interface signal UART0 is connected to 6,7 pins of MAX485 chip, 2 of the MAX485 chip, 3,4,5 pin ground connection in addition, and 8 pins connect power supply, and 1 pin then is connected to the P0.1 pin of single-chip microcomputer.
Rs 232 serial interface signal UART1 imports as second serial through the P0.3 pin that level transferring chip U2 is connected to single-chip microcomputer.Adopt the MAX485 chip such as, level transferring chip U2, rs 232 serial interface signal UART1 is connected to 6,7 pins of MAX485 chip, 2 of the MAX485 chip, 3,4,5 pin ground connection in addition, and 8 pins connect power supply, and 1 pin then is connected to the P0.3 pin of single-chip microcomputer.
Simulating signal ADC0 is connected to the AIN0.0 pin of said single-chip microcomputer, as analog input.
As an embodiment of the utility model, also comprise the build-out resistor R1 that is arranged on the signal reflex that is used for eliminating the serial communication cable on the rs 232 serial interface signal UART0 end, the two ends of this build-out resistor R1 are connected to two input ends of rs 232 serial interface signal UART0 respectively.Also comprise the build-out resistor R2 that is arranged on the signal reflex that is used for eliminating the serial communication cable on the rs 232 serial interface signal UART1 end in addition, the two ends of this build-out resistor R2 are connected to two input ends of rs 232 serial interface signal UART1 respectively.
An embodiment as the utility model; Also comprise the oscillator that constitutes by capacitor C 1, C2, quartz crystal G1 and single-chip microcomputer U3; Capacitor C 1 one end ground connection, the other end is connected to first end of quartz crystal G1, capacitor C 2 one end ground connection; The other end is connected to second end of quartz crystal G1, and first end of quartz crystal G1 and second end then are connected to the XTAL1 pin and the XTAL2 pin of said single-chip microcomputer respectively and think that SCM system provides clock.
In the present embodiment; Interrupt service routine unit in the single-chip microcomputer can be when carrying out collection of serial ports input signal and analog input signal acquisition tasks; Detect the interrupt identification that whether runs into external interrupt INT0; If run into the interrupt identification of external interrupt INT0, then remove the interrupt identification of said external interrupt INT0.Like this, need just to be equivalent to make this pulse width measuring task to carry out in the beginning pulse width measuring task if in the process of other task of single-chip microcomputer execution, run into, the wait next cycle is proceeded to carry out again.Otherwise; If do not carry out aforesaid operations, single-chip microcomputer can remove to carry out the interrupt service routine of INT0, promptly first zero clearing timer T0 again after above-mentioned other task executes so; Restart timer T0 and begin counting, thereby cause the last resulting test result can be littler than actual value.
Interrupt service routine unit further in the single-chip microcomputer is when carrying out collection of serial ports input signal and analog input signal acquisition tasks; Detect the interrupt identification that whether runs into external interrupt INT1; If run into the interrupt identification of external interrupt INT1; Whether the timer T0 that then detects in the single-chip microcomputer starts, if timer T0 starts, then stops timer T0 counting.This way is before other task of execution; If begun to have carried out the pulse width measuring task; And this pulse width measuring task is in the process of other task of execution, to stop; Then need in the interrupt service routine of other task, force to stop timer T0 counting, the clock ticktack cycle that the count value of taking-up timer T0 this moment multiply by timer T0 then is pulse width, thereby can guarantee to obtain at last the correctness of data.Otherwise if do not carry out aforesaid operations, single-chip microcomputer can go to stop to carry out the pulse width measuring task after above-mentioned other task executes again so, thereby causes the last resulting test result can be bigger than actual value.
Another embodiment as the utility model; Interrupt service routine unit in the single-chip microcomputer is when detecting the interrupt identification of external interrupt INT0; Also can first zero clearing timer T0 restart timer T0 counting, remove the interrupt identification of external interrupt INT0 at last, when using this mode; It is not too short needing pulse width; Promptly need after other task is finished, just can run into the rising edge of next pulse,, also can guarantee the correctness of last measurement result even in other task implementation, started timer T0 like this.
Based on said apparatus how the utility model is guaranteed that pulse width task correct measurement is explained in further detail below:
At first, external interrupt INT0 is set in program initialization and INT1 is the negative edge triggering, and timer T0 is a timing mode; Wherein the negative edge of pwm pulse (t0) is caught by INT0, and the rising edge of next pulse (t1) is caught by INT1.Be 0 at the counting of the mid-timer T0 of the interrupt service routine of INT0 (TH0=0, and TL0=0, wherein TH0 is the most-significant byte of timer T0, and TL0 is the least-significant byte of timer T0), start timer simultaneously and begin counting (TR0=1); In the interrupt service routine of INT1, judge whether timer T0 opens earlier, count (TR0=0) if open then stop timer T0, the clock ticktack cycle that the count value of taking-up timer T0 this moment multiply by timer T0 then is pulse width.
In order to guarantee the correct measurement of pwm pulse width, the utility model embodiment is at UART0, and UART1 has increased following two kinds and detected judgement in the ADC0 interrupt service routine:
If a runs into the interrupt identification (IE0=1) of external interrupt INT0; Promptly run into the negative edge of pulse; Then remove the interrupt identification (IE0=0) of external interrupt INT0, perhaps first zero clearing timer T0 restarts timer T0, removes the interrupt identification (IE0=0) of external interrupt INT0 at last;
If b runs into the interrupt identification (IE1=1) of external interrupt INT1, promptly run into the rising edge of next pulse, and timer T0 begun counting when (TR=1), then stop timer T0 counting (TR0=0).
The utility model embodiment is through introducing the judgement that the pulse-width measuring task starts and stops in the interrupt service routine of other task except that the pulse width measuring task; And judge according to this and to come control timer T0, thereby guaranteed the correctness of pulse width measuring data in the single-chip microcomputer.
Above-described specific embodiment; Purpose, technical scheme and beneficial effect to the utility model have carried out further explain, it should be understood that the above is merely the specific embodiment of the utility model; And be not used in the protection domain that limits the utility model; All within the spirit and principle of the utility model, any modification of being made, be equal to replacement, improvement etc., all should be included within the protection domain of the utility model.
Claims (6)
1. guarantee the device of pulse width correct measurement in the multitask SCM system; Said single-chip microcomputer is C8051F020; It is characterized in that; Comprise: phase inverter, first level transferring chip, second level transferring chip; One road signal of pwm pulse inputs to the INT0 external interrupt of the P0.4 pin of said single-chip microcomputer as said SCM system, and another road signal of pwm pulse inputs to the input end of said phase inverter, and the output terminal of said phase inverter is connected to the INT1 external interrupt of the P0.5 pin of said single-chip microcomputer as said SCM system; Rs 232 serial interface signal UART0 imports as first serial through the P0.1 pin that said first level transferring chip is connected to said single-chip microcomputer; Rs 232 serial interface signal UART1 imports as second serial through the P0.3 pin that said second level transferring chip is connected to said single-chip microcomputer, and simulating signal ADC0 is connected to the AIN0.0 pin of said single-chip microcomputer, as analog input; Interrupt service routine unit in the said single-chip microcomputer is used for when carrying out serial ports input signal collection and analog input signal acquisition tasks; Detect whether run into the interrupt identification of external interrupt INT0,, then remove the interrupt identification of said external interrupt INT0 if run into the interrupt identification of external interrupt INT0; And detect whether run into the interrupt identification of external interrupt INT1, if run into the interrupt identification of external interrupt INT1, whether the timer T0 that then detects in the single-chip microcomputer starts, if timer T0 starts, then stops timer T0 counting.
2. guarantee the device of pulse width correct measurement in the multitask SCM system as claimed in claim 1; It is characterized in that; Also comprise first build-out resistor that is arranged on the signal reflex that is used for eliminating the serial communication cable on the first serial input end, and second build-out resistor that is arranged on the signal reflex that is used for eliminating the serial communication cable on the second serial input end.
3. guarantee the device of pulse width correct measurement in the multitask SCM system as claimed in claim 1; It is characterized in that; Also comprise the oscillator that is made up of capacitor C 1, C2, quartz crystal G1 and single-chip microcomputer U3, the two ends of said quartz crystal G1 are connected to the XTAL1 pin and the XTAL2 pin of said single-chip microcomputer respectively and think that said SCM system provides clock.
4. guarantee the device of pulse width correct measurement in the multitask SCM system; Said single-chip microcomputer is C8051F020; It is characterized in that; Comprise: phase inverter, first level transferring chip, second level transferring chip, one road signal of pwm pulse input to the INT0 external interrupt of the P0.4 pin of said single-chip microcomputer as said SCM system, and another road signal of pwm pulse inputs to the input end of said phase inverter; The output terminal of said phase inverter is connected to the ITN1 external interrupt of the P0.5 pin of said single-chip microcomputer as said SCM system; Rs 232 serial interface signal UART0 imports as first serial through the P0.1 pin that said first level transferring chip is connected to said single-chip microcomputer, and rs 232 serial interface signal UART1 imports as second serial through the P0.3 pin that said second level transferring chip is connected to said single-chip microcomputer, and simulating signal ADC0 is connected to the AIN0.0 pin of said single-chip microcomputer; As analog input; Interrupt service routine unit in the said single-chip microcomputer is used for when carrying out serial ports input signal collection and analog input signal acquisition tasks, detecting whether run into the interrupt identification of external interrupt INT0, if run into the interrupt identification of external interrupt INT0; Then first zero clearing timer T0 opening timing device T0 again counts, and removes the interrupt identification of said external interrupt INT0 at last; And detect whether run into the interrupt identification of external interrupt INT1, and if run into the interrupt identification of external interrupt INT1, then detect timer T0 and whether start, if timer T0 starts, then stop timer T0 counting.
5. guarantee the device of pulse width correct measurement in the multitask SCM system as claimed in claim 4; It is characterized in that; Also comprise first build-out resistor that is arranged on the signal reflex that is used for eliminating the serial communication cable on the first serial input end, and second build-out resistor that is arranged on the signal reflex that is used for eliminating the serial communication cable on the second serial input end.
6. guarantee the device of pulse width correct measurement in the multitask SCM system as claimed in claim 4; It is characterized in that; Also comprise the oscillator that is made up of capacitor C 1, C2, quartz crystal G1 and single-chip microcomputer U3, the two ends of said quartz crystal G1 are connected to the XTAL1 pin and the XTAL2 pin of said single-chip microcomputer respectively and think that said SCM system provides clock.
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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CN102298095A (en) * | 2011-06-27 | 2011-12-28 | 中国国土资源航空物探遥感中心 | Method for ensuring accurate measurement on pulse width in multi-task singlechip system and device |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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CN102298095A (en) * | 2011-06-27 | 2011-12-28 | 中国国土资源航空物探遥感中心 | Method for ensuring accurate measurement on pulse width in multi-task singlechip system and device |
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