Host communication circuit, client communication circuit, communication system, sound reproduction device and communication method

Abstract

The host side is adapted to be connected to the client side via a clock line (CLKW), a selection line (SELW), a first data line (DW1) and a second data line (DW2). The host side is configured to transmit a digital selection signal to the client side via the selection line (SELW), the selection signal determining an audio transmission mode or a client communication mode. In addition, in the audio transmission mode, the host side is configured to transmit digital audio data of a first channel and a second channel to the client side via the first and second data lines (DW1, DW2), and in the client communication mode, the host side is configured to perform client communication via the first and second data lines (DW1, DW2).

Description

[0001] The present disclosure relates to a host communication circuit, a client communication circuit, a communication system having such a host communication circuit and such a client communication circuit, to a sound reproduction device having such a communication system, and to a method for communicating between a host side and a client side.

[0002] Sometimes it is necessary to provide different circuit components on different dies or in different chips. If data is to be transmitted between these circuit components, a communication protocol is required. For example, for transmitting audio data, the I2S protocol is well established for transmitting audio data from a transmitter to a receiver over a single data line, thereby also using one line for the clock signal and one line for the word select signal. However, only audio data is transmitted through this protocol. In addition, only one-way communication is possible.

[0003] If other data must be transmitted from the transmitter to the receiver, or even in the other direction, further communication interfaces must be provided on the transmitter side and the receiver side. These require additional signal lines. In addition, two different communication protocols must be implemented on the two dies or two chips.

[0004] The object to be achieved is to provide an efficient communication concept for audio data transmission and bidirectional communication via a limited number of signal lines.

[0005] This object is achieved by the subject matter of the independent claims. Embodiments and developments of the communication concept are defined in the dependent claims.

[0006] The efficient communication concept is based on the idea that two data lines can be provided for communication between the host and the client, both of which can transmit stereo audio data from the host to the client in parallel, and that communication between the host and the client can be established on the same two data lines. This allows, for example, to transmit audio data of a first channel and a second channel in parallel, so that there is no transmission delay between, for example, a left audio channel and a right audio channel. This may be desirable, for example, in noise cancellation applications.

[0007] In order to establish communication between the host and the client, a selection line for transmitting a digital selection signal is foreseen, wherein the selection signal determines the audio transmission mode or the client communication mode, or in other words, determines whether audio data is transmitted from the host to the client or client communication is performed between the host and the client.

[0008] In the client communication mode, a direction indicator can be transmitted from the host to the client in order to define whether data is sent from the host side to the client side or from the client side to the host side. For example, index data and optionally a direction indicator are transmitted via a first data line, for example within a corresponding bit sequence, and payload data are transmitted via a second data line, for example encoded in a second bit sequence. In particular, the transmission of index data and payload data occurs in parallel or simultaneously. In order to establish a timing sequence, both the host side and the client side can be connected to a clock line for transmitting a common clock signal. For example, a clock signal is transmitted from the host side to the client side via the clock line.

[0009] Thus, using only four wires, it is possible to achieve a transmission of audio data between two audio channels without delay, and also to achieve a bidirectional communication between the host and the client. Thus, a communication system having a host communication circuit on the host side and a client communication circuit on the client side can be produced with less manufacturing effort. Furthermore, it reduces any delay problems that occur, for example, when using the conventional I2S protocol for audio data transmission. Client communication via two data lines allows, for example, simple device control of the client by the host.

[0010] If the direction indicator is not transmitted, the communication direction from the host to the client or from the client to the host can be preselected. For example, only one-way communication can occur in this configuration. However, the communication direction can be defined according to a predefined timing scheme or depending on other communication methods.

[0011] For example, the transmission rate of the audio data is higher than the actual playback rate in order to provide a continuous audio data stream on the client side. The actual transmission rate depends, for example, on the ratio between the amount of audio data to be transmitted and the amount of data of the client communication performed. For example, the audio data is transmitted using some kind of time compression.

[0012] In an example implementation of a host communication circuit according to an effective communication concept, the host communication circuit is adapted to be connected to a client communication circuit via a clock line, a selection line, a first data line, and a second data line. The host communication circuit is configured to transmit a digital selection signal to the client communication circuit via the selection line, wherein the selection signal determines an audio transmission mode or a client communication mode. The host communication circuit is also configured to transmit digital audio data of a first channel and a second channel to the client communication circuit via the first data line and the second data line in the audio transmission mode, and to perform client communication via the first data line and the second data line in the client communication mode.

[0013] In some implementations, the host communication circuit is further configured to transmit a direction indicator when performing client communication in the client communication mode. The host communication circuit is further configured to transmit a first bit sequence to the client communication circuit via a first data line, wherein, in the audio transmission mode, the first bit sequence includes audio data of a first channel (e.g., a left audio channel), and when performing client communication, the first bit sequence includes index data. The host communication circuit is configured to transmit a second bit sequence to the client communication circuit via a second data line in the audio transmission mode, wherein the second bit sequence includes audio data of a second channel (e.g., a right audio channel).

[0014] The host communication circuit is further configured to, when performing client communication, transmit a second bit sequence to the client communication circuit via the second data line if the direction indicator is associated with a write mode, wherein the second bit sequence includes payload data. If the direction indicator is associated with a read mode when performing client communication, the host communication circuit receives the second bit sequence from the client communication circuit via the second data line, wherein the second bit sequence includes payload data. There may be a delay between transmitting the index data and receiving the payload data in the read mode.

[0015] In some implementations, when performing client communication, the first bit sequence also includes a direction indicator. However, the direction indicator can be omitted in some applications, so that the write mode or the read mode is predefined or set via different communication channels.

[0016] In some implementations, in the client communication mode, the first bit sequence may include index data, a direction indicator, and an access indicator. The state of the access indicator is determined by evaluating the first bit sequence and the second bit sequence in the client communication circuit or on the client side (if applicable). Therefore, if, for example, there is no data transmission in the client communication mode, it is not necessary to evaluate on the client side, thereby saving power on the client side.

[0017] For example, in client communication mode, the index data determines a target on the client side or in the client communication circuit in write mode, such as a target address. Similarly, in read mode, the index data may determine a source in the client communication circuit or the client side, such as a source address. Such an address may be a memory address or a register address. The target and source may also determine a functional element or functional block on the client side to which data is to be written or from which data is to be read or retrieved.

[0018] For example, the audio transmission mode and the client communication mode are determined by selecting various states or state changes of the signal.

[0019] For example, the audio transmission mode is indicated by changing the selection signal from the first state to the second state, and the client communication mode is indicated by changing the selection signal from the second state to the first state. For example, the selection signal can take only these two states.

[0020] The audio data of the first channel and the second channel can be transmitted simultaneously or in parallel. Therefore, no delay is established between the two channels.

[0021] In some implementations, if the bit information is not transmitted, the host communication circuit or the host side connects the first data line and / or the second data line to a high impedance connection, respectively. For example, by connecting to the high impedance connection, each data line is set to a floating state, i.e., no specific potential is forced to be applied to the data line.

[0022] In some cases, it may not be necessary to transmit audio data from the host side to the client side, while client communication should still be performed, for example, for controlling the client side. The operating mode can still be set to the audio transmission mode by a corresponding state or state change of the selection signal. Therefore, the host communication circuit is configured, for example, to change the state of the selection signal after one clock cycle of the clock signal to indicate the client communication mode if there is no audio data to be transmitted in the audio transmission mode.

[0023] In this configuration, one clock cycle will represent the minimum possible duration of the audio transmission mode. However, in other implementations, the state of the select signal may be changed to indicate the client communication mode after a predetermined number of clock cycles of the clock signal that is less than the normal bit length of the audio data to be transmitted. In both implementations, the throughput of client communications is increased by reducing the time of the audio transmission mode.

[0024] Controlling the client side may include activating and deactivating circuit components on the client side, such as amplifiers, digital-to-analog converters, oscillators, and the like.

[0025] An embodiment of the client communication circuit according to the active communication concept is adapted to be connected to the host communication circuit via a clock line, a select line, a first data line and a second data line.For example, the host communication circuit is implemented according to one of the above examples.

[0026] The client communication circuit receives a digital selection signal from the host communication circuit through a selection line, and the selection signal determines an audio transmission mode or a client communication mode. The client communication circuit receives a first channel and a second channel digital audio signal from the host communication circuit through a first data line and a second data line in the audio transmission mode, and performs client communication through the first data line and the second data line in the client communication mode.

[0027] In some implementations, the client communication circuit is configured to receive a direction indicator when performing client communication in the client communication mode. The client communication circuit receives a first sequence of bits from the host communication circuit via a first data line. In the audio transmission mode, the first sequence of bits includes audio data of the first channel, and, in the client communication mode, the first sequence of bits includes index data and, optionally, a direction indicator, e.g., as described above in conjunction with the host communication circuit. The direction indicator can be omitted in some applications so that a write mode or a read mode is predefined or set via different communication channels.

[0028] Therefore, in the audio transmission mode, the client communication circuit receives the second bit sequence including the audio data of the second channel through the second data line.

[0029] When performing client communication, if the direction indicator is associated with a write mode, a second bit sequence is received from the host communication circuit via the second data line, the second bit sequence including the payload data. If the direction indicator is associated with a read mode, the client communication circuit transmits the second bit sequence to the host communication circuit via the second data line, the second bit sequence including the payload data. As described above, index data can be received in a first cycle of the client communication mode to indicate a read address or source in the client communication circuit, and in a subsequent second cycle of the client communication mode, the respective associated payload data is transmitted to the host communication circuit.

[0030] According to the various implementations of the host communication circuit described above, other implementations of the client communication circuit will become apparent to those skilled in the art.

[0031] The implementation methods of the host communication circuit and the client communication circuit can together constitute a communication system, and the host communication circuit and the client communication circuit are connected through a clock line, a selection line, a first data line and a second data line.

[0032] For example, the host communication circuit and the client communication circuit are specifically designed for audio applications, such that the host communication circuit is provided with an audio processing circuit having a digital signal processor for generating audio data to be transmitted, and the client communication circuit is provided with some audio output circuits, such as an amplifier, for providing the received audio data to one or more speakers.

[0033] For example, the host communication circuitry and the client communication circuitry are implemented on separate dies. The dies may be integrated together in a single package, or may be integrated in separate chip packages. For example, the dies are produced using different semiconductor technologies (e.g., on different wafer types).

[0034] An example implementation of a sound reproduction device according to the concept of effective communication comprises at least one loudspeaker and a communication system according to one of the possible implementations described above. The at least one loudspeaker is, for example, coupled to a client communication circuit. For example, the sound reproduction device is implemented as a headset or an in-ear headset.

[0035] In some implementations, the sound reproduction device also includes at least one noise cancellation microphone and a noise cancellation processor, wherein the noise cancellation processor is coupled to the noise cancellation microphone and the host communication circuit.

[0036] In another aspect of the efficient communication concept, a communication method for communicating between a host side and a client side is provided, the host side and the client side being coupled via a clock line, a selection line, and first and second data lines.

[0037] For example, the method includes: transmitting a digital selection signal from the host side to the client side through a selection line, the selection signal determining an audio transmission mode or a client communication mode; and transmitting digital audio data of a first channel and a second channel to the client side through a first data line and a second data line in the audio transmission mode, and performing client communication between the host side and the client side through the first data line and the second data line in the client communication mode.

[0038] In some implementations, the method further includes: when performing client communication in the client communication mode, transmitting a direction indicator from the host side to the client side; transmitting a first bit sequence from the host side to the client side via a first data line, wherein, in the audio transmission mode, the first bit sequence includes audio data of the first channel, and in the client communication mode, the first bit sequence includes index data; in the audio transmission mode, transmitting a second bit sequence from the host side to the client side via a second data line, wherein the second bit sequence includes audio data of the second channel; when performing client communication, if the direction indicator is associated with a write mode, transmitting a second bit sequence from the host side to the client side via a second data line, wherein the second bit sequence includes payload data; and, when performing client communication, if the direction indicator is associated with a read mode, transmitting a second bit sequence from the client side to the host side via a second data line, wherein the second bit sequence includes payload data. Optionally, the first bit sequence also includes the direction indicator.

[0039] From the above-described various embodiments for a host communication circuit, a client communication circuit and a communication system according to an effective communication concept, further embodiments of the communication method become apparent to a person skilled in the art.

[0040] The effective communication concept will be described in more detail below with reference to the accompanying drawings for several embodiments. The same reference numerals represent signals, elements or components with the same function. As long as the signals, elements or components correspond to each other in function, their description will not be repeated in each of the following figures.

[0041] In the attached picture:

[0042] Figure 1 An example block diagram showing a connection between an audio host and an audio client according to an efficient communication concept;

[0043] Figure 2 An example signal diagram illustrating communications according to an efficient communication concept;

[0044] Figure 3 shows an example signal diagram for audio data transfer and write operations;

[0045] Figure 4 shows an example signal diagram for audio data transfer and read operations;

[0046] Figure 5 shows an example signal diagram of a write operation without audio data transmission;

[0047] Figure 6 shows an example signal diagram of a read operation without audio data transmission;

[0048] Figure 7 An example flow chart of data transmission with audio data is shown;

[0049] Figure 8 An example flow chart showing data transmission without audio data is shown;

[0050] Fig. 9 An example flow chart of a data transfer with a write operation is shown;

[0051] Fig.10 An example flow chart of a data transfer with a read operation is shown;

[0052] Fig.11 An example implementation of a headset is shown;

[0053] Fig.12 An example implementation of a communication system is shown; and

[0054] Fig.13 Further example implementations of communication systems are shown.

[0055] Figure 1An example implementation of a connection between an audio host and an audio client is shown, wherein the audio host includes a host communication circuit HCC as a host, and wherein the audio client includes a client communication circuit PCC as a slave. The host communication circuit HCC and the client communication circuit PCC are connected with four wires, namely a clock line CLKW, a selection line SELW, a first data line DW1 and a second data line DW2. For example, arrows on the wires indicate the communication direction.

[0056] For example, a clock signal is transmitted via the clock line CLKW, for example as a bit clock. A digital selection signal is transmitted via the selection line SELW, which can also be referred to as a frame clock. Both terms will be used as synonyms hereinafter. The first data line DW1 and the second data line DW2 are used to transmit a bit sequence, which may correspond to audio data of a left audio channel and a right audio channel, or to index or address data on the first data line DW1 and payload data on the second data line DW2.

[0057] The content of each bit sequence depends on the operating mode determined by the selection signal or the frame clock, respectively. In particular, the state or state change of the selection signal determines whether the communication system consisting of the host communication circuit HCC and the client communication circuit PCC operates in audio transmission mode or in client communication mode.

[0058] Now refer to Figure 2 , shows an example signal diagram for communication over four wires. For example, a frame clock or select signal that can take two different states indicates an upcoming audio transmission mode by changing from a first high state to a second low state. Similarly, an upcoming client communication mode is indicated by a change in the select signal from the second state to the first state. Compared to the above example, the association of the high state and the low state with the first state and the second state can also be reversed.

[0059] For example, the state change of the selection signal is synchronized with the clock edge of the clock signal or the bit clock, respectively. For the sake of clarity, not all clock cycles are shown. In the audio transmission mode (indicated by "audio data" in the figure), a bit sequence with n bits is transmitted from the host communication circuit to the client communication circuit via two data lines DW1 and DW2, the bit sequence starting with the most significant bit MSB and ending with the least significant bit LSB. As an example, the word length of the bit sequence is selected to be 16, 24 or 32 bits, however, the bit sequence can be fixedly set or automatically set as the state of the selection signal changes.

[0060] As can be seen from the figure, the transmission of the MSB begins one clock cycle after the state change of the select signal. Similarly, the LSB is transmitted in the clock cycle immediately after the state change to the first state, which indicates the upcoming client communication mode, which is indicated by "client communication data" in the figure. For example, this can support better synchronization on the client side. However, in other implementations, such as to establish a left-aligned transmission, it can also be achieved that there is no delay after the state change of the select signal.

[0061] After the transmission of the LSB, a selection bit or access indicator STR is transmitted in the "audio left / address" channel associated with the first data line DW1 to indicate whether the data on the first data line and, if applicable, the second data line DW2 is to be evaluated on the client side. Simultaneously with the access indicator STR, the second data line DW2 is set to a high impedance state, for example by connecting it to a high impedance connection in the host communication circuit. Alternatively, during this period, the second data line DW2 can be set to any other state, for example to indicate a "don't care" state. The access indicator STR allows power to be saved on the client side if client communication is not required. However, the access indicator STR remains optional and can be omitted depending on the desired implementation.

[0062] The access indicator STR is followed by a read or write bit or a direction indicator R / W indicating write mode or read mode to the client communication circuit. In the following, index data, for example in the form of a 7-bit read / write address, is transmitted via the first data line DW1, which index data again starts with the most significant bit MSB. Other bit lengths other than 7 can be used as appropriate.

[0063] On the second data line DW2, in the "Audio Right / Data" channel, a bit sequence comprising payload data in the form of 8-bit read / write data is written to the second data line DW2. Other bit lengths than 8 may be used where appropriate. For example, in write mode, the host communication circuitry transfers payload data to the client communication circuitry, and in read mode, the client communication circuitry transfers payload data to the host communication circuitry.

[0064] It should be noted that the access indicator STR and / or the direction indicator R / W can be omitted in other implementations, or, for example, transmitted via the second data line DW2 instead. For example, the direction indicator R / W can be omitted in some applications so that the write mode or the read mode is predefined or set via different communication channels.

[0065] Figures 3 to 6 Involving based on Figure 2The basic representation of the specific implementation of data transmission.

[0066] For example, Figure 3 A communication sequence with a transmission and write operation of audio data is described. To this end, the selection bit or access indicator STR is set to a high value, for example represented by a logical 1, as well as a direction indicator indicating the write process. On the first data line DW1 associated with the "audio left / address" channel, a write address of 11_hex (0x11) is transmitted to the client side. At the same time, on the "audio right / data" channel associated with the second data line DW2, write data or payload data of 28_hex (0x28) is encoded as a bit sequence.

[0067] Now refer to Figure 4 , showing two cycles of audio transmission mode and client communication mode respectively. For audio transmission, refer to the previous example. Figure 4 Involving a communication with a read operation. In the first cycle, the read address 11_hex (0x11) is transmitted via the first data line DW1, while the second data line is set to high impedance or don't care state. In the second cycle of the client communication mode, the read address is transmitted again. On the second data line DW2, the client side transmits a payload 28_hex (0x28), which has been read out at the read address indicated in the first cycle, for example.

[0068] In the second cycle of the client communication mode, instead of transmitting the read address again, another source address can be transmitted, which source address can be the basis for the readout in the next cycle of the client communication mode, not shown here.

[0069] Figure 5 and Figure 6 corresponds to communication without audio transmission, but otherwise corresponds to Figure 3 and 4 Specifically, as described in Figure 3 In the example shown in FIG. 1 , the client communication mode is used to transfer payload data 28_hex (0x28) to write address 11_hex (0x11).

[0070] Similarly, combining Figure 6 The client communication described corresponds to Figure 4 The read operation described in the example.

[0071] Figure 7An example flow chart of communication in a communication system is shown. For example, to indicate an upcoming audio transmission mode, a selection signal is changed from a first state to a second state. Then, as described in more detail above, after one clock cycle or alternatively immediately, the host side begins to transmit audio data from the host side to the client side via the first data line and the second data line. Then, the selection signal is changed from the second state to the first state to indicate an upcoming client communication mode. Then, client communication is performed. Afterwards, the process can begin again.

[0072] Figure 8 Shown based on Figure 7 In particular, Figure 7 Describes the Figure 3 communication, Figure 8 Corresponds to Figure 5 , where no audio data is transmitted and only one or more clock cycles of the bit clock are waited for.

[0073] Fig. 9 Shows the corresponding Figure 3 or Figure 5 Another flow chart of a signal diagram of a control signal, in which a write operation is performed. Starting from the top box, the selection signal changes from the second state to the first state to indicate the upcoming client communication mode. Then, the host side transmits the write indication bit to the client side via the first signal line, and transmits the index bit sequence corresponding to the write address to the client via the first signal line. Simultaneously with the first two boxes, the host side transmits the data bit sequence or write data to the client side via the second signal line. Afterwards, the selection signal changes from the first state to the second state to indicate the audio transmission mode. In the following, audio data transmission is performed, or one or more clock cycles are waited, as described above.

[0074] Fig.10 An additional flow chart is shown for a read operation instead of a write operation, thus corresponding to Figure 4 or Figure 6 In the first frame, the select signal changes from the second state to the first state to indicate the upcoming client communication mode. The host side transmits the read indication bit to the client side through the first signal line, and then transmits the index bit sequence to the client side to indicate the source address or read address in the client. Figure 4 or Figure 6 , during which the second signal line is set to a high impedance state or a don't care state. Thereafter, the select signal is changed from the first state to the second state to indicate an upcoming audio transmission mode. Hereinafter, audio data transmission is performed or one or more clock cycles are waited before the select signal is changed from the second state back to the first state to continue the client communication mode.

[0075] Then, the read indication bit is transmitted to the client via the first signal line, and then the index bit sequence is transmitted to the client. During this period, the client side transmits the payload data as a data bit sequence from the client to the host side via the second signal line. After this, the selection signal changes from the first state to the second state to indicate the upcoming audio transmission mode again. In this mode, the audio data transmission can be performed again or one or more clock cycles can be waited. Then, the process can be restarted, for example, by continuing in the first frame.

[0076] A communication system including a host communication circuit and a client communication circuit can be used in a sound reproduction device such as a headset or an earphone. Fig.11 An example of such a headset with a loudspeaker and a communication system CCS is shown, both of which are encapsulated in a housing HS of the headset HP. In this example, a microphone MIC is also provided as a noise cancellation microphone for performing noise cancellation. The loudspeaker can be coupled to the client communication circuit PCC directly or via another circuit such as a driver circuit or an amplifier circuit, and the microphone can be coupled to a noise cancellation processor, which is integrated with the communication system CCS and connected to the host communication circuit HCC. In various implementations, the microphone MIC can be a feedforward (FF) microphone or a feedback (FB) microphone, and a second microphone can also be foreseen to achieve hybrid noise cancellation with both FF and FB.

[0077] Fig.12 An example implementation is shown in which both the host communication circuit HCC and the client communication circuit PCC are implemented on separate dies, which are integrated in separate chip packages.

[0078] In contrast, Fig.13 In an implementation manner, the host communication circuit HCC and the client communication circuit PCC are integrated together in a single package.

[0079] exist Fig.12 and Fig.13 In the two implementations, the host and the client are connected through their own four lines, namely, a clock line CLKW, a selection line SELW, and data lines DW1 and DW2.

[0080] In the following, further aspects of the present disclosure are described. The various aspects are listed for easy reference to the features of other aspects.

[0081] 1. A host communication circuit, which is adapted to be connected to a client communication circuit via a clock line, a selection line, a first data line and a second data line, wherein the host communication circuit is configured to

[0082] - transmitting a digital selection signal to the client communication circuit via the selection line, the selection signal determining the audio transmission mode or the client communication mode; and

[0083] - transmitting digital audio data of the first channel and the second channel to the client communication circuit through the first and second data lines in the audio transmission mode, and performing client communication through the first and second data lines in the client communication mode.

[0084] 2. The host communication circuit according to aspect 1, wherein the host communication circuit is configured to

[0085] - a transmission direction indicator when performing client communication in said client communication mode;

[0086] - transmitting a first bit sequence to the client communication circuit via the first data line, wherein, in the audio transmission mode, the first bit sequence comprises audio data of the first channel, and, when performing client communication, the first bit sequence comprises index data;

[0087] - in the audio transmission mode, transmitting a second bit sequence to the client communication circuit via the second data line, wherein the second bit sequence includes audio data of the second channel;

[0088] - when performing client communication, if the direction indicator is associated with a write mode, transmitting a second bit sequence to the client communication circuit via the second data line, wherein the second bit sequence comprises payload data; and

[0089] - when performing client communication, if the direction indicator is associated with a read mode, receiving a second bit sequence from the client communication circuit via the second data line, wherein the second bit sequence comprises payload data.

[0090] 3. The host communication circuit of aspect 2, wherein, when performing client communication, the first bit sequence further includes the direction indicator.

[0091] 4. A host communication circuit according to aspect 3, wherein, in the client communication mode, the first bit sequence includes the index data, the direction indicator and the access indicator, wherein the state of the access indicator determines whether the first bit sequence is evaluated in the client communication circuit and the second bit sequence is evaluated if applicable.

[0092] 5. A host communication circuit according to any one of aspects 2 to 4, wherein, in the client communication mode, the index data determines a target in the client communication circuit in the write mode, in particular a target address, and determines a source in the client communication circuit in the read mode, in particular a source address.

[0093] 6. The host communication circuit according to any one of aspects 1 to 5, wherein the audio transmission mode and the client communication mode are determined by respective states or state changes of the selection signal.

[0094] 7. The host communication circuit according to any one of aspects 1 to 6 is configured to indicate the audio transmission mode by changing the selection signal from a first state to a second state, and to indicate the client communication mode by changing the selection signal from the second state to the first state.

[0095] 8. The host communication circuit according to any one of aspects 1 to 7, configured to transmit audio data of the first channel and the second channel simultaneously or in parallel.

[0096] 9. The host communication circuit according to any one of aspects 1 to 8, configured to connect the first data line and / or the second data line to a high impedance connection respectively if there is no bit information to be transmitted.

[0097] 10. The host communication circuit according to any one of aspects 1 to 9, configured to transmit a clock signal to the client communication circuit through the clock line.

[0098] 11. The host communication circuit according to aspect 10 is configured to change the state of the selection signal to indicate the client communication mode after one clock cycle of the clock signal if there is no audio data to be transmitted in the audio transmission mode.

[0099] 12. The host communication circuit according to aspect 10 is configured to change the state of the selection signal to indicate the client communication mode after a predetermined number of clock cycles of the clock signal if there is no audio data to be transmitted in the audio transmission mode, and the number is less than the normal bit length of the audio data to be transmitted.

[0100] 13. A client communication circuit adapted to be connected to a host communication circuit via a clock line, a select line, a first data line and a second data line, the client communication circuit being configured to

[0101] - receiving a digital selection signal from the host communication circuit via the selection line, the selection signal determining an audio transmission mode or a client communication mode; and

[0102] - receiving digital audio data of a first channel and a second channel from the host communication circuit through the first and second data lines in the audio transmission mode, and performing client communication through the first and second data lines in the client communication mode.

[0103] 14. The client communication circuit according to aspect 13, wherein the client communication circuit is configured to

[0104] - receiving a direction indicator when performing client communication in said client communication mode;

[0105] - receiving a first bit sequence from the host communication circuit via the first data line, wherein in the audio transmission mode, the first bit sequence comprises audio data of the first channel, and when performing client communication, the first bit sequence comprises index data;

[0106] - in the audio transmission mode, receiving a second bit sequence from the host communication circuit through the second data line, wherein the second bit sequence includes audio data of the second channel;

[0107] - when performing client communication, if the direction indicator is associated with a write mode, receiving a second bit sequence from the host communication circuit via the second data line, wherein the second bit sequence includes payload data; and

[0108] - when performing client communication, if the direction indicator is associated with a read mode, transmitting a second bit sequence to the host communication circuit via the second data line, wherein the second bit sequence comprises payload data.

[0109] 15. The client communication circuit of aspect 14, wherein when performing client communication, the first bit sequence further includes the direction indicator.

[0110] 16. A client communication circuit according to aspect 15, wherein, in the client communication mode, the first bit sequence includes the index data, the direction indicator and the access indicator, wherein the state of the access indicator determines whether the first bit sequence and, if applicable, the second bit sequence are evaluated in the client communication circuit.

[0111] 17. A client communication circuit according to any one of aspects 14 to 16, wherein, in the client communication mode, the index data determines a target in the client communication circuit in the write mode, in particular a target address, and determines a source in the client communication circuit in the read mode, in particular a source address.

[0112] 18. The client communication circuit according to any one of aspects 13 to 17, wherein the audio transmission mode and the client communication mode are determined by respective states or state changes of the selection signal.

[0113] 19. The client communication circuit of any one of aspects 13 to 18, wherein the audio transmission mode is indicated by changing the selection signal from a first state to a second state, and the client communication mode is indicated by changing the selection signal from the second state to the first state.

[0114] 20. The client communication circuit according to any one of aspects 13 to 19, configured to receive audio data of the first channel and the second channel simultaneously or in parallel.

[0115] 21. The client communication circuit according to any one of aspects 13 to 20, configured to receive a clock signal from the host communication circuit via the clock line.

[0116] 22. A communication system comprising the host communication circuit according to any one of aspects 1 to 12 and the client communication circuit according to any one of aspects 13 to 21, wherein the host communication circuit and the client communication circuit are connected to each other via the clock line, the selection line, the first data line and the second data line.

[0117] 23. The communication system of clause 22, wherein the host communication circuitry and the client communication circuitry are implemented on separate dies.

[0118] 24. The communication system of clause 23, wherein the dies are integrated together in a single package.

[0119] 25. The communication system of clause 23, wherein the die is integrated in a single chip package.

[0120] 26. A sound reproduction device comprising at least one speaker and a communication system according to any one of aspects 22 to 25, wherein the at least one speaker is coupled to a client communication circuit.

[0121] 27. The sound reproduction device according to aspect 26, which is implemented as a headphone or an earphone.

[0122] 28. The sound reproduction device of aspect 26 or 27, further comprising at least one noise cancellation microphone and a noise cancellation processor, wherein the noise cancellation processor is coupled to the noise cancellation microphone and the host communication circuit.

[0123] 29. A communication method for communicating between a host side and a client side, wherein the host side and the client side are coupled via a clock line, a selection line, a first data line and a second data line, the method comprising:

[0124] - transmitting a digital selection signal from the host side to the client side via the selection line, the selection signal determining an audio transmission mode or a client communication mode; and

[0125] -In the audio transmission mode, digital audio data of the first channel and the second channel are transmitted from the host side to the client side through the first and second data lines, and in the client communication mode, client communication is performed between the host side and the client side through the first and second data lines.

[0126] 30. The method according to aspect 29, wherein

[0127] - when performing client communication in the client communication mode, transmitting a direction indicator from the host side to the client side;

[0128] - transmitting a first bit sequence from the host side to the client side via the first data line, wherein in the audio transmission mode, the first bit sequence comprises audio data of the first channel, and in the client communication mode, the first bit sequence comprises index data;

[0129] - in the audio transmission mode, transmitting a second bit sequence from the host side to the client side through the second data line, wherein the second bit sequence includes audio data of the second channel;

[0130] - when performing client communication, if the direction indicator is associated with a write mode, transmitting a second bit sequence from the host side to the client side via the second data line, wherein the second bit sequence includes payload data; and,

[0131] - when performing client communication, if the direction indicator is associated with a read mode, transmitting a second bit sequence from the client side to the host side via the second data line, wherein the second bit sequence includes payload data

[0132] 31. The method of clause 30, wherein, when performing client communications, the first bit sequence further comprises the direction indicator.

[0133] 32. A method according to aspect 31, wherein, in the client communication mode, the first bit sequence includes the index data, the direction indicator and the access indicator, wherein the state of the access indicator determines whether the first bit sequence is evaluated on the client side and the second bit sequence is evaluated if applicable.

[0134] 33. A method according to one of aspects 30 to 32, wherein, in the client communication mode, the index data determines the target on the client side in the write mode, in particular the target address, and determines the source on the client side in the read mode, in particular the source address.

[0135] 34. The method according to any one of aspects 29 to 33, wherein the audio transmission mode and the client communication mode are determined by respective states or state changes of the selection signal.

[0136] 35. The method according to any one of aspects 29 to 34, wherein the audio transmission mode is indicated by changing the selection signal from a first state to a second state, and the client communication mode is indicated by changing the selection signal from the second state to the first state.

[0137] 36. A method according to any one of aspects 29 to 35, wherein the audio data of the first channel and the audio data of the second channel are transmitted simultaneously or in parallel.

[0138] 37. The method according to any one of clauses 29 to 36, wherein if there is no bit information to be transmitted, the host side connects the first data line and / or the second data line to a high impedance connection, respectively.

[0139] 38. The method according to any one of aspects 29 to 37, wherein a clock signal is transmitted from the host side to the client side via the clock line.

[0140] 39. A method according to clause 38, wherein if there is no audio data to be transmitted in the audio transmission mode, the state of the selection signal is changed after one clock cycle of the clock signal to indicate the client communication mode.

[0141] 40. A method according to aspect 38, wherein if there is no audio data to be transmitted in the audio transmission mode, the state of the selection signal is changed to indicate the client communication mode after a predetermined number of clock cycles of the clock signal, and the number is less than the normal bit length of the audio data to be transmitted.

[0142] Description of Reference Numerals

[0143] CLKW clock line

[0144] SELW Select Line

[0145] DW1, DW2 data cable

[0146] HCC Host Communication Circuit

[0147] PCC Client Communication Circuit

[0148] CCS Communication System

[0149] R / W Direction Indicator

[0150] STR access indicator

[0151] BCLK clock signal

[0152] HP Headphones

[0153] SP Speakers

[0154] HS housing

[0155] MIC Microphone

Claims

1. A host communication circuit (HCC) adapted to be connected to a client communication circuit (PCC) via a clock line (CLKW), a select line (SELW), a first data line (DW1) and a second data line (DW2), the host communication circuit (HCC) being configured to - transmitting a digital selection signal to the client communication circuit (PCC) via the selection line (SELW), the selection signal determining the audio transmission mode or the client communication mode; as well as - in the audio transmission mode, transmitting digital audio data of a first channel to the client communication circuit (PCC) through the first data line (DW1) and transmitting digital audio data of a second channel to the client communication circuit (PCC) through the second data line (DW2), and performing client communication through the first data line (DW1) and the second data line (DW2) in the client communication mode; - a transmission direction indicator (R / W) when performing client communication in said client communication mode; - transmitting a first bit sequence to the client communication circuit (PCC) via the first data line (DW1), wherein, in the audio transmission mode, the first bit sequence comprises audio data of the first channel and, when performing client communication, the first bit sequence comprises index data; - in the audio transmission mode, transmitting a second bit sequence to the client communication circuit (PCC) via the second data line (DW2), wherein the second bit sequence comprises audio data of the second channel; - when performing client communication, if the direction indicator (R / W) is associated with a write mode, transmitting a second bit sequence to the client communication circuit (PCC) via the second data line (DW2), wherein the second bit sequence comprises payload data; and - when performing client communication, if the direction indicator (R / W) is associated with a read mode, receiving a second bit sequence from the client communication circuit (PCC) via the second data line (DW2), wherein the second bit sequence comprises payload data.

2. The host communication circuit (HCC) according to claim 1, wherein: When performing client communication, the first bit sequence further includes the direction indicator (R / W).

3. The host communication circuit (HCC) according to claim 2, wherein: In the client communication mode, the first bit sequence comprises the index data, the direction indicator (R / W) and an access indicator (STR), wherein the state of the access indicator (STR) determines whether the first bit sequence and, if applicable, the second bit sequence are evaluated in the client communication circuit (PCC).

4. A host communication circuit (HCC) according to any one of claims 1 to 3, wherein: In the client communication mode, the index data determines a target in the client communication circuit (PCC) in the write mode and determines a source in the client communication circuit (PCC) in the read mode.

5. A host communication circuit (HCC) according to any one of claims 1 to 3, wherein: The audio transmission mode and the client communication mode are determined by respective states or state changes of the selection signal.

6. The host communication circuit (HCC) according to one of claims 1 to 3, configured to transmit a clock signal (BCLK) to the client communication circuit (PCC) via the clock line (CLKW).

7. A host communication circuit (HCC) according to any one of claims 1 to 3, wherein: In the client communication mode, the index data determines a target address in the client communication circuit (PCC) in the write mode and determines a source address in the client communication circuit (PCC) in the read mode.

8. A client communication circuit (PCC) adapted to be connected to a host communication circuit (HCC) via a clock line (CLKW), a select line (SELW), a first data line (DW1) and a second data line (DW2), the client communication circuit (PCC) being configured to - receiving a digital selection signal from the host communication circuit (HCC) via the selection line (SELW), the selection signal determining the audio transmission mode or the client communication mode; as well as - receiving digital audio data of a first channel from the host communication circuit (HCC) through the first data line (DW1) and receiving digital audio data of a second channel from the host communication circuit (HCC) through the second data line (DW2) in the audio transmission mode, and performing client communication through the first data line (DW1) and the second data line (DW2) in the client communication mode; - receiving a direction indicator (R / W) when performing client communication in said client communication mode; - receiving a first bit sequence from the host communication circuit (HCC) via the first data line (DW1), wherein, in the audio transmission mode, the first bit sequence comprises audio data of the first channel and, when performing client communication, the first bit sequence comprises index data; - receiving a second bit sequence from the host communication circuit (HCC) via the second data line (DW2) in the audio transmission mode, wherein the second bit sequence comprises audio data of the second channel; - when performing client communication, if the direction indicator (R / W) is associated with a write mode, receiving a second bit sequence from the host communication circuit (HCC) via the second data line (DW2), wherein the second bit sequence comprises payload data; and - when performing client communication, if the direction indicator (R / W) is associated with a read mode, transmitting a second bit sequence to the host communication circuit (HCC) via the second data line (DW2), wherein the second bit sequence comprises payload data.

9. A communication system (CCS), comprising a host communication circuit (HCC) according to one of claims 1 to 7 and a client communication circuit (PCC) according to claim 8, wherein the host communication circuit and the client communication circuit are connected to each other via a clock line (CLKW), a selection line (SELW), a first data line (DW1) and a second data line (DW2).

10. A communication system (CCS) according to claim 9, wherein: The host communication circuit (HCC) and client communication circuit (PCC) are implemented on separate dies.

11. A communication system (CCS) according to claim 10, wherein: The tube core - integrated together in a single package; or -Integrated in a single chip package.

12. A sound reproduction device comprising at least one loudspeaker and a communication system (CCS) according to one of claims 9 to 11, wherein: The at least one speaker is coupled to the client communication circuit (PCC).

13. The sound reproduction device according to claim 12, wherein: The sound reproduction device is a headphone or an earphone.

14. A communication method for communicating between a host side and a client side, wherein the host side and the client side are coupled via a clock line (CLKW), a selection line (SELW), a first data line (DW1) and a second data line (DW2), the method comprising: - transmitting a digital selection signal from the host side to the client side via the selection line (SELW), the selection signal determining an audio transmission mode or a client communication mode; as well as - in the audio transmission mode, transmitting digital audio data of a first channel from the host side to the client side through the first data line (DW1) and transmitting digital audio data of a second channel from the host side to the client side through the second data line (DW2), and in the client communication mode, performing client communication between the host side and the client side through the first data line (DW1) and the second data line (DW2); - when performing client communication in the client communication mode, transmitting a direction indicator (R / W) from the host side to the client side; - transmitting a first bit sequence from the host side to the client side via the first data line (DW1), wherein in the audio transmission mode, the first bit sequence comprises audio data of the first channel, and in the client communication mode, the first bit sequence comprises index data; - in the audio transmission mode, transmitting a second bit sequence from the host side to the client side via the second data line (DW2), wherein the second bit sequence includes audio data of the second channel; - when performing client communication, if the direction indicator (R / W) is associated with a write mode, transmitting a second bit sequence from the host side to the client side via the second data line (DW2), wherein the second bit sequence comprises payload data; and, - when performing client communication, if the direction indicator (R / W) is associated with a read mode, transmitting a second bit sequence from the client side to the host side via the second data line (DW2), wherein the second bit sequence comprises payload data.

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