CN201042053Y - Hot swap processing circuit for HDMI signal receiver - Google Patents
Hot swap processing circuit for HDMI signal receiver Download PDFInfo
- Publication number
- CN201042053Y CN201042053Y CNU200720078707XU CN200720078707U CN201042053Y CN 201042053 Y CN201042053 Y CN 201042053Y CN U200720078707X U CNU200720078707X U CN U200720078707XU CN 200720078707 U CN200720078707 U CN 200720078707U CN 201042053 Y CN201042053 Y CN 201042053Y
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- Prior art keywords
- hot plug
- hdmi
- pin
- signal
- resistance
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Abstract
The utility model relates to a HDMI circuit and provides a hot plug processing circuit positioned on a HDMI signal receiving end to ensure that the receiving end identifies the hot plug signal accurately. The utility model comprises a HDMI interface and an E-EDID module, wherein, the power pin of the HDMI interface is connected with the E-EDID module; and the hot plug detecting pin of the HDMI interface is connected with the power pin through a resistance. Besides, the utility model also comprises a reset signal generating device, and the output end of the reset signal generating device is connected between the hot plug detecting pin and the resistance, while the input end of the reset signal generating device is connected with a MCU. The output end of the reset signal generating device receives a reset signal sent by the MCU. The level of the hot plug detecting pin is recovered to the high level after being set to a low level. The utility model has the advantages that the hot plug signal can be reliably identified by the receiving end no matter the sending end device is perfect or not.
Description
Technical field
The utility model relates to HDMI (HDMI (High Definition Multimedia Interface)) circuit, particularly the hot plug of HDMI signal receiving end (HPD) treatment circuit.
Background technology
The complexity of the line between the transmission of high-definition digital video signal equipment has been simplified in the appearance of HDMI greatly.HDMI has set up and a kind ofly by high speed serialization digital interface signaling various high-definition signal transmitting terminals (as DVD player, DVD burner, set-top box, digital video camera) has been connected, and the standard method to receiving terminal (as digital TV, projecting apparatus etc.) of the digital video of uncompressed and audio transmission.
The correct processing of hot plug signal is the precondition that HDMI receiving terminal and transmitting terminal carry out data communication.The HDMI agreement has following regulation to the hot plug signal:
1, for HDMI signal receiving end (as television set), when its E-EDID (strengthening identification expansion identification video data) was not readable as yet, the hot plug port can not be high level state.
2, the output impedance requirement is 1000 Ω ± 20%.
3, the HDMI transmitting terminal is connected with receiving terminal, when the E-EDID data can read, the hot plug port must be in high level state, this moment transmitting terminal to detect hot plug be high level, then begin the E-EDID module and the HDMI process chip of receiving terminal are composed the address, and then the communication of beginning DDC (data display channel).
4, among the HDMI to the definition of high/low level:
| Transmitting terminal (source) | Receiving terminal (sink) | |
| High level | 2.0v-5.3v | 2.4v-5.3v |
| Low level | 0v-0.8v | 0v-0.4v |
When carrying out repeatedly the plug of HDMI connecting line, in the time of on the HDMI connecting line is not pegged graft, the hot plug detection port of transmitting terminal is in unsettled high-impedance state, transmitting terminal can think that be high level this moment, also can think low level, the hot plug signal distinguishing that will be in unsettled hot plug signal and high level that promptly it can not be affirmed comes out.When the consequence of not bringing was certainly like this extracted the HDMI connecting line exactly, DDC interrupted, and transmitting terminal is thought communication abnormality, and with sign off, but judge that still the hot plug signal is high level (in fact being in high-impedance state) this moment; When once more the HDMI connecting line being plugged, hot plug is high, but transmitting terminal is still thought and will do not carried out communication by the communication abnormality state that is in.
Prior art is provided with the hot plug treatment circuit at transmitting terminal usually in order to address the above problem.This treatment circuit can be forced transmitting terminal hot plug input port is changed to low level under the situation that the HDMI connecting line is extracted.This method designs at transmitting terminal, in agreement, this is not carried out compulsory requirement, therefore can't guarantee that each HDMI transmitting terminal has all adopted this technology, when transmitting terminal did not adopt this technology, the problem of hot plug signal may appear accurately discerning in receiving terminal.
The utility model content
Technical problem to be solved in the utility model is, a kind of hot plug treatment circuit at the HDMI signal receiving end is provided, and can guarantee that receiving terminal accurately discerns the hot plug signal.
The utility model is to solve the problems of the technologies described above the technical scheme that is adopted to be, the hot plug treatment circuit of HDMI signal receiving end comprises HDMI interface, E-EDID module; Wherein the power pins of HDMI interface links to each other with the E-EDID module, and the hot plug of HDMI interface detects pin and links to each other with power pins by resistance; Comprise a reseting signal generator in addition, the output of reseting signal generator is connected described hot plug and detects between pin and the described resistance, and the input of reseting signal generator links to each other with MCU; The input of described reseting signal generator receives the reset signal of sending from MCU, after hot plug is detected that the level of pin is of short duration and is changed to low level, reverts to high level.
Concrete, described reseting signal generator is a triode, and the base stage of described triode links to each other with MCU, and collector electrode is connected described hot plug and detects between pin and the described resistance, grounded emitter.
Concrete, the resistance of described resistance is 1000 Europe.
The beneficial effects of the utility model are that no matter whether the sending ending equipment design is perfect, can both guarantee to discern the hot plug signal reliably from receiving terminal.
Description of drawings
Fig. 1 is HDMI signal receiving end plug-and-play circuit commonly used;
Fig. 2 is the plug-and-play circuit of HDMI signal receiving end among the embodiment.
Embodiment
The connector of HDMI interface has A, B two classes, wherein the general category-A interface that adopts in household appliances.With the category-A interface is example, and clear and definite standard has all been made in the encapsulation of HDMI agreement docking port and the definition of interface pin:
The pinout of category-A interface:
| The pin sequence number | Definition | The pin sequence number | Definition |
| 1 | Minimize the positive signal of transmission differential data 2 | 2 | The shielding of transition minimized differential signaling data 2 | |
| 3 | Minimize the negative polarity signal of transmission differential data 2 | 4 | Minimize the positive signal of transmission |
|
| 5 | The shielding of transition minimized |
6 | Minimize the negative polarity signal of transmission |
|
| 7 | Minimize the positive signal of transmission differential data 0 | 8 | The shielding of transition minimized differential signaling data 0 | |
| 9 | Minimize the negative polarity signal of transmission differential data 0 | 10 | Minimize the positive signal of transmission differential clocks | |
| 11 | Minimize the shielding of transmission differential clock signal | 12 | Minimize the negative polarity signal of transmission differential clocks | |
| 13 | Consumer electrical equipment contact | 14 | Keep | |
| 15 | Serial clock | 16 | Serial data | |
| 17 | The ground of display data passage | 18 | + |
|
| 19 | Hot plug detects pin |
The hot plug signal is in a pair of connection of HDMI, for the realization of hot plug designs.Briefly; when transmitting terminal and receiving terminal link; receiving terminal can be responded the hot plug signal and give transmitting terminal; and then transmitting terminal can start DDC, thereby reads the information in the receiving terminal E-EDID module, carries out the mutual of HDCP (high-definition digital content protecting agreement) then; if mutual authentication success; then video, audio frequency operate as normal are failed otherwise connect, and different system has different processing.
The E-EDID module is a data storage that is placed on the HDMI signal receiving end; The HDMI agreement has been made following standard: all HDMI signal receiving ends all must have the E-EDID structure; The E-EDID structure must be fully and VESA (frequency electronic standard association of making video recording) and CEA-861B operating such.
As shown in Figure 1, the plug-and-play circuit of existing HDMI signal receiving end comprises HDMI interface, E-EDID module; The 5V power pins of HDMI interface links to each other with the E-EDID module, and the hot plug of HDMI interface detects pin and links to each other with the E-EDID module by resistance R.When transmitting terminal was not connected with receiving terminal, the 5V power pins was unsettled, and hot plug detects pin and is not in high level state.After the HDMI connecting line is plugged, the 5V power pins by connecting line provide+the 5V power supply is to the E-EDID module, and also by resistance R the voltage that hot plug detects pin drawn high (being approximately equal to 5V), to satisfy the definition requirement of HDCP agreement to the hot plug signal.If receiving terminal is wrong on the hot plug signal of unsettled high-impedance state of identification and high level state, receiving terminal and transmitting terminal just can not communicate.
When the utility model links to each other with receiving terminal at transmitting terminal, reseting signal generator by the receiving terminal increase, the hot plug of its HDMI interface of pressure detects pin level and is set to low 1 second, and then it is changed to high level, hot plug detects pin and can detect hot plug signal process from low to high like this, promptly can very clearly know and join with transmitting terminal this moment, and the hot plug signal is a high level, can begin the transmission of DDC data, it is mutual to carry out HCDP.
As shown in Figure 2, as reseting signal generator, the base stage of triode links to each other with MCU to adopt a triode (model is T3904), and collector electrode is connected described hot plug and detects between pin and the described resistance R, grounded emitter; Hot plug detects pin and links to each other with the 5V power pins by resistance R; The 5V power pins links to each other with the E-EDID module.
The 5V power pins links to each other with the collector electrode of triode by resistance R, and this resistance R constitutes the collector electrode pull-up resistor R of triode; Base stage links to each other with the control end of MCU, and this control port is subjected to artificial control, the output reset signal; Grounded emitter.
When transmitting terminal be connected with receiving terminal finish after, can be artificial send indication to MCU, be example with the television set, carry out input pattern identification by remote controller, in the process of identification, MCU sends to triode collection utmost point output reset signal.Reset signal is a level signal of putting high 1 second, and when being changed to high level, triode saturation conduction, collector potential are 0.2-0.3V, and it is 0.2-0.3V that hot plug detects the pin current potential; After reset signal put high 1 second, MCU was changed to low level with it again, triode by, collector potential returns to 5V, promptly is that to detect the pin current potential be high level in hot plug.
Like this, hot plug detection pin clearly detects the HDMI connecting line and has been connected to receiving terminal, and is high level, begin to attempt DDC then when mutual, triode is in cut-off state, so hot plug detects the value that the output impedance of pin approximates resistance R, be 1000 Ω, satisfy the requirement of agreement.
Claims (3)
1.HDMI the hot plug treatment circuit of signal receiving end, comprise HDMI interface, E-EDID module, the power pins of HDMI interface links to each other with the E-EDID module, the hot plug of HDMI interface detects pin and links to each other with power pins by resistance, it is characterized in that, also comprise a reseting signal generator, the output of reseting signal generator is connected described hot plug and detects between pin and the described resistance, and the input of reseting signal generator links to each other with MCU.
2. the hot plug treatment circuit of HDMI signal receiving end as claimed in claim 1, it is characterized in that described reseting signal generator is a triode, the base stage of described triode links to each other with MCU, collector electrode is connected described hot plug and detects between pin and the described resistance, grounded emitter.
3. the hot plug treatment circuit of HDMI signal receiving end as claimed in claim 1 is characterized in that, the resistance of described resistance is 1000 Europe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU200720078707XU CN201042053Y (en) | 2007-03-08 | 2007-03-08 | Hot swap processing circuit for HDMI signal receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU200720078707XU CN201042053Y (en) | 2007-03-08 | 2007-03-08 | Hot swap processing circuit for HDMI signal receiver |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201042053Y true CN201042053Y (en) | 2008-03-26 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU200720078707XU Expired - Fee Related CN201042053Y (en) | 2007-03-08 | 2007-03-08 | Hot swap processing circuit for HDMI signal receiver |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201042053Y (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102213974A (en) * | 2010-04-12 | 2011-10-12 | 鸿富锦精密工业（深圳）有限公司 | Computer motherboard |
| CN103176935A (en) * | 2011-12-23 | 2013-06-26 | 闻泰通讯股份有限公司 | Parallel bus interface communication method supporting hot plugging |
| CN103259999A (en) * | 2012-02-20 | 2013-08-21 | 联发科技（新加坡）私人有限公司 | Hot plug detection (HPD) signal output control method and high definition multimedia interface (HDMI) receiving end device and system |
| CN103684500A (en) * | 2012-09-25 | 2014-03-26 | 华为技术有限公司 | Pairing method of wireless transmitting terminal and wireless receiving terminal and related device |
| CN113253017A (en) * | 2021-04-16 | 2021-08-13 | 广州朗国电子科技有限公司 | Electrical performance test module of HDMI port |
| CN113485955A (en) * | 2021-07-07 | 2021-10-08 | 中国科学技术大学先进技术研究院 | Equipment transmission circuit, device and system |
| CN114624635A (en) * | 2022-05-17 | 2022-06-14 | 陕西天视致远航空技术有限公司 | Plug-pull detection system and method of VGA display interface and electronic equipment |
-
2007
- 2007-03-08 CN CNU200720078707XU patent/CN201042053Y/en not_active Expired - Fee Related
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102213974A (en) * | 2010-04-12 | 2011-10-12 | 鸿富锦精密工业（深圳）有限公司 | Computer motherboard |
| CN103176935A (en) * | 2011-12-23 | 2013-06-26 | 闻泰通讯股份有限公司 | Parallel bus interface communication method supporting hot plugging |
| CN103259999A (en) * | 2012-02-20 | 2013-08-21 | 联发科技（新加坡）私人有限公司 | Hot plug detection (HPD) signal output control method and high definition multimedia interface (HDMI) receiving end device and system |
| US9329672B2 (en) | 2012-02-20 | 2016-05-03 | Mediatek Singapore Pte. Ltd. | High-definition multimedia interface (HDMI) receiver apparatuses, HDMI systems using the same, and control methods therefor |
| CN103259999B (en) * | 2012-02-20 | 2016-06-15 | 联发科技（新加坡）私人有限公司 | HPD signal output control method, HDMI receiving device and system |
| CN103684500A (en) * | 2012-09-25 | 2014-03-26 | 华为技术有限公司 | Pairing method of wireless transmitting terminal and wireless receiving terminal and related device |
| CN103684500B (en) * | 2012-09-25 | 2016-08-24 | 华为技术有限公司 | Pairing method of wireless transmitting terminal and wireless receiving terminal and related device |
| CN113253017A (en) * | 2021-04-16 | 2021-08-13 | 广州朗国电子科技有限公司 | Electrical performance test module of HDMI port |
| CN113485955A (en) * | 2021-07-07 | 2021-10-08 | 中国科学技术大学先进技术研究院 | Equipment transmission circuit, device and system |
| CN113485955B (en) * | 2021-07-07 | 2024-02-23 | 合肥中科采象科技有限公司 | Equipment transmission circuit, device and system |
| CN114624635A (en) * | 2022-05-17 | 2022-06-14 | 陕西天视致远航空技术有限公司 | Plug-pull detection system and method of VGA display interface and electronic equipment |
| CN114624635B (en) * | 2022-05-17 | 2023-07-25 | 陕西天视致远航空技术有限公司 | Plug detection system and method of VGA display interface and electronic equipment |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080326 Termination date: 20160308 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |