CN201449605U - Single chip microcomputer serial port communication circuit application system - Google Patents
Single chip microcomputer serial port communication circuit application system Download PDFInfo
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- CN201449605U CN201449605U CN2009200329668U CN200920032966U CN201449605U CN 201449605 U CN201449605 U CN 201449605U CN 2009200329668 U CN2009200329668 U CN 2009200329668U CN 200920032966 U CN200920032966 U CN 200920032966U CN 201449605 U CN201449605 U CN 201449605U
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- serial port
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- chip microcomputer
- transceiver
- application system
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Abstract
The utility model provides a single chip microcomputer serial port communication circuit application system, the application system mainly resolves the problem in the prior art which is caused by the feed of the serial port that the running of the single chip microcomputer is not reliable because the power-on reset of the single chip microcomputer can not be implemented The system comprises an outside serial port data sending terminal T x +, an outside serial port data sending terminal T x -, a transceiver and the single chip microcomputer. The transceiver is provided with an outside data receiving terminal R x + and an outside data receiving terminal R x -. The transceiver is also provided with a data output terminal R x, the outside serial port data sending terminal T x + is connected with the outside data receiving terminal R x -. The outside serial port data sending terminal T x -is connected with the outside data receiving terminal R x +, a logic inversing circuit which is used to inverse the output data from the data output terminal R x is connected between the transceiver and the single chip microcomputer. The data output terminal R x is connected with the data receiving terminal of the logic inversing circuit, a data receiving terminal R X D of the single chip microcomputer is connected with the data output terminal of the logic inversing circuit.
Description
Technical field
The utility model relates to scm application system, relates in particular to a kind of singlechip serial port communication circuit application system.
Background technology
In scm application system, can communicate with computing machine or other single-chip microcomputers in order to make single-chip microcomputer, the inner integrated general serial asynchronism transceiver of single-chip microcomputer (Universal AsynchronousReceiverTransmitter, UART), i.e. serial ports.Along with the development of single-chip microcomputer, serial ports becomes the indispensable part of single-chip microcomputer gradually.
Single-chip microcomputer is used for communication system more, and the general requirement of communication system should guarantee communication quality, satisfies reliable communications again, and this makes the single-chip microcomputer that is operated in the communication system need reliable electrification reset control, satisfies the requirement of the high reliability of communication facilities.
Serial port circuit mostly is the RS422 interface protocol in the existing scm application system, connect chip by low-power consumption RS422 transmitting-receiving interface chip (as MAX488) as interface, but there are a lot of problems in this structure.
The microcontroller serial port receiving end is defaulted as high level, when outside serial ports carrying load ability is strong, can make 5 volts power ends of single-chip microcomputer produce 2 volts of left and right sides voltages, can cause the single-chip microcomputer can't electrification reset like this, the functional reliability reduction.Especially as watchdog circuit the time, may cause thrashing, like this The application of single-chip computer brought very big restriction, also restrict the development of single-chip microcomputer.
Summary of the invention
The purpose of this utility model is: a kind of singlechip serial port communication circuit application system is provided, to solve in the prior art because the serial ports feed causes the single-chip microcomputer can't electrification reset, insecure problem of working.
The technical scheme that the utility model solves is as follows:
The singlechip serial port communication circuit application system that the utility model provides comprises external serial port data transmitting terminal Tx+, external serial port data transmitting terminal Tx-, transceiver and single-chip microcomputer, and transceiver is provided with external data receiving end Rx+ and external data receiving end Rx-; Transceiver also is provided with data output end Rx, and external serial port data transmitting terminal Tx+ is connected with external data receiving end Rx; External serial port data transmitting terminal Tx-is connected with external data receiving end Rx+; Be connected with between transceiver and the single-chip microcomputer and be used for Boolean complementation circuit that the data of data output end Rx output are negated; Data output end Rx is connected with the data receiver of Boolean complementation circuit; The data receiver RXD of single-chip microcomputer is connected with the data output end of Boolean complementation circuit.
The above Boolean complementation circuit is to realize the Boolean complementation functional circuit; The Boolean complementation circuit can be that model is 74LS04,74LS06, CD4049, CD4069, SN5406 or FPGA programming device.
The transmitting-receiving interface chip of the above transceiver can be MAX488.
The above transceiver can be a low-power consumption RS422 transceiver.
The above single-chip microcomputer can be 51 series monolithics, can select that model is 8031,8951,8052,8752,8032,8952 for use, 51 series monolithics of 80C51,87C51,80C31,89C51,80C52,87C52,80C32 or 89C52.
Advantage of the present utility model is:
The scm application system that the utility model provides, the microcontroller power supply low-voltage that the isolated serial port input end brings makes the single-chip microcomputer electrification reset reliable, working stability.
The scm application system that the utility model provides is applied in the signal level converting system, has reduction with good protection effect, efficiently solves problems of the prior art.
Description of drawings
Fig. 1 is the utility model circuit principle structure figure;
Fig. 2 is the utility model embodiment circuit diagram.
Embodiment
In conjunction with the accompanying drawings the utility model is narrated:
As shown in Figure 1 and Figure 2, the described singlechip serial port communication circuit application system of present embodiment, comprise external serial port data transmitting terminal Tx+, external serial port data transmitting terminal Tx-, with MAX488 as the low-power consumption RS422 transceiver of interface chip and the 89C51 of 51 series monolithics, the RS422 transceiver is provided with external data receiving end Rx+ (i.e. 8 pin) and external data receiving end Rx-(i.e. 7 pin); The RS422 transceiver also is provided with data output end Rx.
External serial port data transmitting terminal Tx+ is connected with external data receiving end Rx-, and external serial port data transmitting terminal Tx-is connected with external data receiving end Rx+; Be connected with between the 89C51 of RS422 transceiver and 51 series monolithics and be used for Boolean complementation circuit that the data of data output end Rx output are negated.
The data output end Rx of RS422 transceiver is connected with the data receiver of Boolean complementation circuit, and the data receiver RXD of the 89C51 of 51 series monolithics is connected with the data output end of Boolean complementation circuit.
During work, the data terminal acquiescence level that MAX488 after the reversal connection receives is a low level, can not feed back 2 volts of left and right sides voltages at the microcontroller power supply end by the microcontroller serial port receiving end, but the data that receive this moment are the anti-of True Data, reverse chip 74LS04 by the Boolean complementation circuit negates to data once more again, can obtain single-chip microcomputer needs the just True Data of receipts, and by twice reverse isolation, the microcontroller power supply end can not feed back 2 volts of left and right sides voltages.Single-chip microcomputer is electrification reset reliably.
Claims (6)
1. a singlechip serial port communication circuit application system comprises external serial port data transmitting terminal Tx+, external serial port data transmitting terminal Tx-, transceiver and single-chip microcomputer, and described transceiver is provided with external data receiving end Rx+ and external data receiving end Rx-; Described transceiver also is provided with data output end Rx, it is characterized in that: described external serial port data transmitting terminal Tx+ is connected with external data receiving end Rx-; Described external serial port data transmitting terminal Tx-is connected with external data receiving end Rx+; Be connected with between described transceiver and the single-chip microcomputer and be used for Boolean complementation circuit that the data of data output end Rx output are negated; Described data output end Rx is connected with the data receiver of Boolean complementation circuit; The data receiver RXD of described single-chip microcomputer is connected with the data output end of Boolean complementation circuit.
2. according to the described singlechip serial port communication circuit application system of claim 1, it is characterized in that: described Boolean complementation circuit is to realize the Boolean complementation functional circuit; Described Boolean complementation circuit is that model is 74LS04,74LS06, CD4049, CD4069, SN5406 or FPGA programming device.
3. according to claim 1 or 2 described singlechip serial port communication circuit application systems, it is characterized in that: the transmitting-receiving interface chip of described transceiver is MAX488.
4. according to the described singlechip serial port communication circuit application system of claim 3, it is characterized in that: described transceiver is a low-power consumption RS422 transceiver.
5. according to the described singlechip serial port communication circuit application system of claim 4, it is characterized in that: described single-chip microcomputer is 51 series monolithics.
6. state singlechip serial port communication circuit application system according to claim 5, it is characterized in that: described 51 series monolithics are that model is 8031,8951,8052,8752,8032,8952,80C51,87C51,80C31,89C51,80C52,87C52,80C32 or 89C52.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200329668U CN201449605U (en) | 2009-04-30 | 2009-04-30 | Single chip microcomputer serial port communication circuit application system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200329668U CN201449605U (en) | 2009-04-30 | 2009-04-30 | Single chip microcomputer serial port communication circuit application system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201449605U true CN201449605U (en) | 2010-05-05 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009200329668U Expired - Lifetime CN201449605U (en) | 2009-04-30 | 2009-04-30 | Single chip microcomputer serial port communication circuit application system |
Country Status (1)
| Country | Link |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101876961B (en) * | 2009-04-30 | 2011-12-07 | 中国科学院西安光学精密机械研究所 | Singlechip serial port communication circuit application system |
-
2009
- 2009-04-30 CN CN2009200329668U patent/CN201449605U/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101876961B (en) * | 2009-04-30 | 2011-12-07 | 中国科学院西安光学精密机械研究所 | Singlechip serial port communication circuit application system |
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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: 20100505 Effective date of abandoning: 20090430 |
|
| AV01 | Patent right actively abandoned |
Granted publication date: 20100505 Effective date of abandoning: 20090430 |