Abstract:
An electronic system is provided, including a host electronic device and a first electronic device. The host electronic device is coupled to a mini display port (mDP) bus composed of a first lane and a second lane, in which the host electronic device turns off the second lane according to a disable signal in a first communication protocol mode. The first electronic device is coupled to the mDP bus and outputs a detection signal to the host electronic device, in which, when the first electronic device is coupled to the host electronic device, the host electronic device communicates with the first electronic device through the first lane in the first communication protocol mode and communicates with the first electronic device through the second lane in a second communication protocol mode, according to an enable signal.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of Taiwan Patent Application No. 101113412, filed on Apr. 16, 2012, and the entirety of which is incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an electronic system, and in particular, relates to an electronic system with a mini display port (mDP). 
     Description of the Related Art 
     As computer and information technology industries continue developing, new peripheral equipment has been developed for connection to personal computers and notebook computers, including Internet network devices and external storage devices. Nevertheless, the traditional system architectures operating on the personal computers and notebook computers can not perform data communication with new communication protocols. Thus an electronic system and a communication method thereof are in need for increasing usability of the electronic system. 
     BRIEF SUMMARY OF THE INVENTION 
     In one aspect of the invention, an electronic system is disclosed, comprising a host electronic device and a first electronic device. The host electronic device is coupled to a Mini Display Port (mDP) bus comprising a first channel and a second channel, wherein when in a first communication protocol mode, the host electronic device disconnects the second channel, according to a disable signal. The first electronic device, coupled to the mDP bus, is configured to output a detection signal to the host electronic device. When the first electronic device is coupled to the host electronic device, the host electronic device communicates with the first electronic device in the first communication protocol mode via the first channel, and communicates with the first electronic device in the second communication protocol mode via the second channel, according to an enable signal. 
     In another aspect of the invention, a host electronic device is provided, comprising a processing unit, a multiplexer and an embedded control unit. The processing unit is coupled to a first channel of an mDP bus. The multiplexer is configured to couple a second channel of the mDP bus to a ground level according to a disable signal in a first communication protocol mode. The embedded control unit is coupled to the multiplexer, wherein when the host electronic device is coupled to a first electronic device, the multiplexer is configured to couple the second channel to the embedded control unit according to an enable signal, so that the processing unit is configured to communicate with the first electronic device in the first communication protocol via the first channel, and the embedded control unit is configured to communicate with the first electronic device in a second communication protocol mode via the second channel. 
     In another aspect of the invention, another electronic device is described, comprising a processing unit and an embedded control unit. The processing unit, coupled to a first channel of an mDP bus, is configured to output a detection signal to a host electronic device, and communicate with the host electronic device in a first communication protocol mode. The embedded control unit, coupled to the second channel, is configured to communicate with the host electronic device in a second communication protocol mode. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a block diagram of an electronic system  100  according to an embodiment of the invention. 
         FIG. 2  shows a block diagram of a host electronic device according to an embodiment of the invention. 
         FIG. 3  is a block diagram of an electronic device according to an embodiment of the invention. 
         FIG. 4  is a block diagram of an electronic system according to an embodiment of the invention. 
         FIG. 5  is a flowchart of a communication method according to an embodiment of the invention. 
         FIG. 6  is a flowchart of a communication method according to another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
       FIG. 1  is a block diagram of an electronic system  100  according to an embodiment of the invention. The electronic system  100  includes a host electronic device and an electronic device  120 . Specifically, the host electronic device  110  is coupled to a mini display port (mDP) including a first channel L 1  and a second channel L 2 . In a first communication protocol such as a thunderbolt protocol mode, the host electronic device  110  can disconnect the second channel L 2  according to a disable signal DS. In the embodiment, the first channel L 1  is formed by three lanes, or, the first channel L 1  contains lanes LANE 0 , LANE 1 , and LANE 2 . Each lane LANE 0 , LANE 1 , or LANE 2  can include a p line and an n line. The first channel L 1  contains 6 lines, namely, LAN 0 ( p ), LAN 0 ( n ), LAN 1 ( p ), LAN 1 ( n ), LAN 2 ( p ) and LAN 2 ( n ). The second channel L 2  is formed by one lane, or lane LANE 3 . LANE 3  contains a p line and an n line, thereby consequently, the second channel L 1  can contain 2 lines, or LAN 3 ( p ) and LAN 3 ( n ). 
     The electronic device  120 , coupled to the mDP bus BS, is configured to output a detection signal TS to the host electronic device  110 . When the electronic device  120  is coupled to the host electronic device  110 , the host electronic device  110  can communicate with the electronic device  120  in the first communication protocol mode via the first channel L 1 , and open the second channel L 2  according to an enable signal ES, so that the host electronic device  110  can communicate with the electronic device  120  in a second communication protocol mode such as an I2C (Inter-Integrated Circuit, I2C) protocol mode via the second channel L 2 . 
     In the embodiment, the host electronic device  110  can be an electronic device with various configurations, for example, a hand-held device, a portable device, a personal digital assistant (PDA), a multi-processor system, a microprocessor-based or programmable consumer electronic device, a network computer, a mini computer, a server computer or the like, and is not limited thereto. 
     The electronic device  120  can be any type of peripheral devices or Input/Output (I/O) expanders. For instance, the electronic device  120  may be a TV box, an optical disk drive, a Hard disk driver (HDD), a graphics processing unit (GPU) device or a speaker. It should be understood that the electronic device  120  may be any electronic device with the thunderbolt interface, electronic device with a data transfer rate exceeding the thunderbolt interface, or electronic device with a daisy chain configuration. 
       FIG. 2  shows a block diagram of a host electronic device according to an embodiment of the invention, with the host electronic device  210  identical to the host electronic device  110  in  FIG. 1 . As depicted in  FIG. 2 , the host electronic device  210  contains a processing unit  211 , a multiplexer  212 , and an embedded control unit EC 1 . The processing unit  211  is coupled to the first channel L 1  and the multiplexer  212 . The multiplexer  212  is coupled to the processing unit  211 , for use when in a third communication protocol mode, such as a Display Port protocol mode, coupling the second channel L 2  to the processing unit  211 , and when in the first communication protocol mode, coupling the second channel L 2  to a ground, according to the disable signal DS. 
     The embedded control unit EC 1  is coupled to the multiplexer  212 . The multiplexer  212  can couple the second channel L to the embedded control unit EC 1  according to the enable signal ES, such that the embedded control unit EC 1  can communicate with an electronic device such as the electronic device  120 , in the second communication protocol mode via the second channel L 2 . In the embodiments, the processing unit  211  or other internal devices in the host electronic device  210  can output the enable signal ES or the disable signal DS to the controller node of the multiplexer  212  based on a detection signal TS. In some embodiments, the enable signal ES and the disable signal DS are output from the electronic device  220 , and the detection signal TS can contain the enable signal ES and the disable signal DS. 
     The host electronic device  210  may determine whether the electronic device  220  is the electronic device  221  having a display port interconnection unit, or the electronic device  222  or the electronic device  120  having the thunderbolt unit, based on the detection signal TS output by the electronic device  220  via the mDP bus BS. Further, the host electronic device  210  may selectively open or disconnect the second channel L 2  via the multiplexer  212 . For example, when the electronic device  220  is the electronic device  221  coupled to host electronic device  210 , the multiplexer  212  can couple the second channel L 2  to the processing unit  211 , so that the host electronic device  210  can communicate with the electronic device  220  by a third communication protocol mode, such as a Display Port protocol mode, via the second channel L 2  and the first channel L 1  (i.e. the channels LANE 0 ˜LANE 3 ). 
     When the electronic device  220  is the electronic device  222  coupled to host electronic device  210 , the multiplexer  212  can couple the second channel L 2  to the ground based on the detection signal DS, so that the host electronic device  210  can disconnect the second channel L 2 . The host electronic device  210  can communicate with the electronic device  220  in the first communication protocol mode merely via the first channel L 1 . 
     When the electronic device  220  is the electronic device  120  in  FIG. 1  and is coupled to host electronic device  210 , the multiplexer  212  can couple the second channel L 2  to the embedded control unit EC 1  according to the enable signal ES, so that the processing unit  211  can communicate with the electronic device  220  in the first communication protocol mode via the first channel L 1 , and the embedded control unit EC 1  can communicate with the electronic device  220  in the second communication protocol mode via the second channel L 2 . 
       FIG. 3  is a block diagram of an electronic device according to an embodiment of the invention, with the electronic device  320  identical to the electronic device  120  in  FIG. 1 . As illustrated in  FIG. 3 , the electronic device  320  includes a processing unit  321  and an embedded control unit EC 2 . The processing unit  321  is coupled to the first channel L 1  of the mDP bus BS to output the detection signal TS to the host electronic device such as the host electronic device  210  and communicate with the host electronic device in the first communication protocol mode. The embedded control unit EC 2  is coupled to the second channel L 2  to communicate with the host electronic device in the second communication protocol mode. 
       FIG. 4  is a block diagram of an electronic system according to an embodiment of the invention. As shown in  FIG. 4 , the electronic system  400  includes the host electronic device  410  and a plurality of the electronic devices  4201 ˜ 420 N. Each of the electronic devices  4201 ˜ 420 N may be the electronic device  320 . The host electronic device  410  may be the host electronic device  210 . The electronic device  4202  is coupled to the electronic device  4201  in the daisy chain configuration, and the electronic device  420 N is coupled to the electronic device  420  (N−1) in the daisy chain configuration. Each of the electronic devices  4201 ˜ 420 N and the host electronic device has a mini display port connection unit connecting to the mDP bus BS. The host electronic device  410  can communicate with the electronic device  420 N in the first communication protocol mode via the first channel L 1 , and communicate with the electronic device  420 N in the second communication protocol mode via the second channel L 2 . 
       FIG. 5  is a flowchart of a communication method according to an embodiment of the invention, adopted by the host electronic device  110  coupled to the mDP bus BS. As depicted by  FIG. 5 , the communication method includes the following steps. 
     In Step S 51 , the host electronic device  110  can determine an operation mode for the mDP bus BS as being one of the first, second, and third modes according to the detection signal TS output from the mDP bus BS to the host electronic device  110 . 
     In Step S 52 , when the mDP bus BS is in the first mode, the host electronic device  110  can communicate with the electronic device  120  in the first communication protocol mode via the mDP bus BS, open the second channel L 2  of the mDP bus BS based on the enable signal ES, and communicate with the electronic device  120  in the second communication protocol mode via the second channel L 2 . 
     In Step S 53 , when the mDP bus BS is in the second mode, the host electronic device  110  can communicate with the electronic device  221  by the third communication protocol mode via the first channel L 1  and second channel L 2 . 
     In Step S 54 , when the mDP bus BS is in the third mode, the host electronic device  110  can disconnect the second channel L 2  based on the disable signal DS, and communicate with the electronic device  222  in the first communication protocol mode via the first channel L 1 . 
     Moreover, the electronic device  4202  or the electronic device  420 N can be coupled to the electronic device  4201  or the electronic device  420 (N−1) by the daisy chain configuration, so that the host electronic device  410  can communicate with the electronic device  4202  or the electronic device  420 N in the first communication protocol mode via the first channel L 1 , and communicate with the electronic device  4202  or the electronic device  420 N in the second communication protocol mode via the second channel L 2 . 
       FIG. 6  is a flowchart of a communication method according to another embodiment of the invention. The communication method in  FIG. 6  is similar to that in  FIG. 5 , wherein Steps S 62 ˜S 64  are identical to Steps S 52 ˜S 54 . The two communication methods are distinct in that in Step S 65 , the host electronic device  110  can determine whether the mDP bus BS is in the first mode based on the detection signal TS output from the mDP bus BS to the host electronic device  110 . When the mDP bus BS is in the first mode, Step S 62  is performed. When the mDP bus BS is not in the first mode, Step S 66  is performed, wherein the host electronic device  110  can determine whether the mDP bus BS is in the second mode based on the detection signal TS. When the mDP bus BS is in the second mode, Step S 63  is performed. When the mDP bus BS is not in the second mode, the host electronic device  110  can determine that the mDP bus BS is in the third mode, thus Step S 64  is performed. 
     In the embodiments, under the thunderbolt protocol mode, the electronic system  100  can perform data transmission using an unused channel such as the second channel L 2  by the internal integrated circuit bus. Consequently the host electronic device  110  can perform data transmission between the internal integrated circuit bus and the electronic device  120  by the mDP bus BS without the need for an additional bus. 
     As used herein, the term “determining” encompasses calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” may include resolving, selecting, choosing, establishing and the like. 
     The various illustrative logical blocks, modules and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array signal (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller or state machine. 
     While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. Those who are skilled in this technology can still make various alterations and modifications without departing from the scope and spirit of this invention. Therefore, the scope of the invention shall be defined and protected by the following claims and their equivalents.