Bluetooth controller circuit for reducing possibility of noise generation

A Bluetooth controller circuit includes: a clock counter arranged to operably generate a first count value corresponding to a reference clock signal; a count value adjusting circuit arranged to operably generate a second count value according to the first count value; a time slot determining circuit arranged to operably determine timing of respective transmission slots according to the second count value; a transceiver circuit arranged to operably transmit Bluetooth signal in transmission slots determined by the time slot determining circuit; and a control circuit, coupled with the count value adjusting circuit, the time slot determining circuit, and the transceiver circuit, and arranged to operably control operations of the count value adjusting circuit, the time slot determining circuit, and the transceiver circuit.

BACKGROUND

The disclosure generally relates to Bluetooth technologies and, more particularly, to a Bluetooth controller circuit for reducing possibility of noise generation.

As is well known in related art, a Bluetooth communication device conducts Bluetooth packet transmission in the transmission slot (TX slot) defined by the Bluetooth communication protocols, and most transmission slots are periodic slots. In other words, the operations of transmitting Bluetooth packets conducted by the Bluetooth communication device are typically periodical operations. Accordingly, from another aspect, the Bluetooth signals transmitted by the Bluetooth communication device typically has a specific frequency.

However, since the Bluetooth communication protocols specifies the period length (e.g., 312.5 μs) of some transmission slots, the frequency of some Bluetooth signals issued by the Bluetooth communication device will fall within the frequency range that can be perceived by human ears. Therefore, the traditional Bluetooth communication device sometimes generates noises that can be perceived by human ears during the transmission of Bluetooth signals, which may negatively affect the user experience of the Bluetooth communication device, and may even cause the user to feel uncomfortable.

SUMMARY

An example embodiment of a Bluetooth controller circuit is disclosed, comprising: a clock counter, arranged to operably generate a first count value corresponding to a reference clock signal; a count value adjusting circuit, coupled with the clock counter, and arranged to operably adjust the first count value to generate a second count value, so that magnitudes of the second count value intermittently exhibits a non-linear change; a time slot determining circuit, coupled with the count value adjusting circuit, and arranged to operably adjust timing of respective transmission slots according to the second count value to cause interval between adjacent transmission slots to not remain consistency; a transceiver circuit, coupled with the time slot determining circuit, and arranged to operably transmit Bluetooth signals in transmission slots configured by the time slot determining circuit; and a control circuit, coupled with the count value adjusting circuit, the time slot determining circuit, and the transceiver circuit, and arranged to operably operations of the count value adjusting circuit, the time slot determining circuit, and the transceiver circuit; wherein the time slot determining circuit is further arranged to operably adjust trigger timing of respective transmission events within a target transmission slot according to the second count value to cause interval between adjacent transmission events in the target transmission slot to not remain consistency.

Another example embodiment of a Bluetooth controller circuit is disclosed, comprising: a clock counter arranged to operably generate a first count value corresponding to a reference clock signal; a count value adjusting circuit, coupled with the clock counter, and arranged to operably generate a second count value according to the first count value; a time slot determining circuit, coupled with the count value adjusting circuit, and arranged to operably configure timing of respective transmission slots according to the second count value; a transceiver circuit, coupled with the time slot determining circuit, and arranged to operably transmit Bluetooth signals in transmission slots configured by the time slot determining circuit; a control circuit, coupled with the count value adjusting circuit, the time slot determining circuit, and the transceiver circuit, and arranged to operably control operations of the count value adjusting circuit, the time slot determining circuit, and the transceiver circuit.

Both the foregoing general description and the following detailed description are examples and explanatory only, and are not restrictive of the invention as claimed.

DETAILED DESCRIPTION

Reference is made in detail to embodiments of the invention, which are illustrated in the accompanying drawings. The same reference numbers may be used throughout the drawings to refer to the same or like parts, components, or operations.

FIG.1shows a simplified functional block diagram of a Bluetooth controller circuit according to a first embodiment of the present disclosure. As shown inFIG.1, the Bluetooth controller circuit100comprises a first clock counter112, a first count value adjusting circuit114, a first time slot determining circuit116, a transceiver circuit120, an audio processing circuit130, and a control circuit140.

The first clock counter112is arranged to operably generate a first count value CV1corresponding to a reference clock signal CLKR. For example, the first clock counter112may conduct a counting operation based on a specific edge (e.g., the rising edge or the falling edge) of the reference clock signal CLKR to generate a first count value CV1corresponding to the quantity of the specific edge of the reference clock signal CLKR. In general, the reference clock signal CLKR has a stable frequency, and thus the magnitude of the first count value CV1generated by the first clock counter112will increase stably and exhibit a linear change. The first clock counter112may reset the magnitude of the first count value CV1at an appropriate time.

The first count value adjusting circuit114is coupled with the first clock counter112, and arranged to operably generate a second count value CV2according to the first count value CV1.

The first time slot determining circuit116is coupled with the first count value adjusting circuit114, and arranged to operably decide the timing of respective transmission slots (TX slots) and the timing of respective reception slots (RX slots) according to the second count value CV2.

The transceiver circuit120is coupled with the first time slot determining circuit116, and arranged to operably transmit Bluetooth signals in the transmission slots configured by the first time slot determining circuit116, and arranged to operably receive Bluetooth signals in the reception slots configured by the first time slot determining circuit116. In practice, the transceiver circuit120may be coupled with an appropriate antenna102of various types.

In practice, the transceiver circuit120may be realized with various appropriate Bluetooth communication circuits supporting various versions of Bluetooth communication protocols.

The audio processing circuit130is coupled with an audio playback circuit104and a sound capturing circuit106. In practice, the audio playback circuit104may be realized with various appropriate circuits capable of receiving and playing audio data, such as various speakers, ear phones, headset devices, or the like. The sound capturing circuit106may be realized with various appropriate circuits capable of capturing sound and converting sound into corresponding audio signals, such as various types of microphones. The audio processing circuit130may be realized with a digital computing circuit, a microprocessor, an ASIC, or a digital-to-analog converter (DAC) capable of conducting various encoding/decoding processing and/or data format conversion on audio data.

The control circuit140is coupled with the first count value adjusting circuit114, the first time slot determining circuit116, the transceiver circuit120, and the audio processing circuit130, and arranged to operably control the operations of the first count value adjusting circuit114, the first time slot determining circuit116, the transceiver circuit120, and the audio processing circuit130.

In operations, the audio processing circuit130may process the audio data transmitted from other Bluetooth devices (e.g., to encode or decode the audio data, and/or to conduct format conversion on the audio data) according to the instructions of the control circuit140, and may control the audio playback circuit104to play the contents of the audio data. The audio processing circuit130is further arranged to operably encode the sounds captured by the sound capturing circuit106to generate corresponding sound data. The control circuit140may transmit the sound data generated by the audio processing circuit130to other Bluetooth devices (not shown) through the transceiver circuit120.

In addition, the control circuit140may utilize a first control signal CTL1to control the first count value adjusting circuit114to generate the second count value CV2by adopting different approaches in different operation stages of the Bluetooth controller circuit100, and may control the first time slot determining circuit116to decide the timing of respective transmission slots by adopting different approaches.

In practice, the control circuit140may be realized with an appropriate packet processing circuit, a digital computing circuit, a microprocessor, a single processor module, a combination of multiple processor modules, or an ASIC having appropriate computing capabilities and capable of parsing and generating Bluetooth packets.

The term “Bluetooth packet” used throughout the description and the claims also encompass various protocol data units (PDUs) specified by various Bluetooth communication standards.

In practical applications, different functional blocks of the aforementioned Bluetooth controller circuit100may be realized with separate circuits or may be integrated into a single IC chip or a single device. For example, the aforementioned transceiver circuit120and/or audio processing circuit130may be integrated into the control circuit140.

Alternatively, all functional blocks of the Bluetooth controller circuit100may be integrated into a single IC chip, a mobile communication device (e.g., a cell phone), a wearable device, a tablet computer, a notebook computer, a desktop computer, an audio broadcast system, a voice guidance system, a voice broadcasting system, a vehicular communication device, a satellite communication device, a smart TV, a Bluetooth smart speaker, or the like.

The operation of dynamically adjusting slot timing conducted by the Bluetooth controller circuit100will be further described in the following by reference toFIG.2throughFIG.7.FIG.2throughFIG.7show simplified schematic slot timing diagrams illustrating dynamical slot timing adjustment conducted by the Bluetooth controller circuit ofFIG.1according to different embodiments of the present disclosure.

InFIG.2throughFIG.7, the upper part of the drawing is the slot timing when the Bluetooth controller circuit does not adjust the timing of the transmission slots, and the lower part of the drawing is the slot timing of the transmission slots adjusted by the Bluetooth controller circuit100.

When there is no need to adjust the timing of the transmission slots, the control circuit140may instruct the first count value adjusting circuit114to simply utilize the first count value CV1generated by the first clock counter112to be the second count value CV2. In other words, the second count value CV2will be the same as the first count value CV1, and thus the magnitude of the second count value CV2also increases stably and exhibits a linear change.

In this situation, as shown in the upper part ofFIG.2throughFIG.7, when the second count value CV2reaches a first predetermined value at a first time point T1, the first time slot determining circuit116may generate a transmission slot indication signal210corresponding to a start point of a first transmission slot201, so that the transceiver circuit120begins a Bluetooth signal transmission operation according to the transmission slot indication signal210. When the second count value CV2reaches a second predetermined value, the first time slot determining circuit116may generate a reception slot indication signal240corresponding to the start point of a first reception slot203, so that the transceiver circuit120begins a Bluetooth signal receiving operation according to the reception slot indication signal240.

Then, when the second count value CV2reaches a third predetermined value at a second time point T2, the first time slot determining circuit116generate a transmission slot indication signal220corresponding to a start point of a second transmission slot205, so that the transceiver circuit120again starts a Bluetooth signal transmission operation according to the transmission slot indication signal220. When the second count value CV2reaches a fourth predetermined value, the first time slot determining circuit116may generate a reception slot indication signal250corresponding to a second reception slot207, so that the transceiver circuit120again starts a Bluetooth signal receiving operation according to the reception slot indication signal250.

Afterwards, when the second count value CV2reaches a fifth predetermined value at a third time point T3, the first time slot determining circuit116may generate a transmission slot indication signal230corresponding to a start point of a third transmission slot209, so that the transceiver circuit120again starts a Bluetooth signal transmission operation according to the transmission slot indication signal230.

The above analogy can also apply to the subsequent operation, so the transceiver circuit120is enabled to alternately switch between a transmission mode and a receiving mode according to the relevant indication signals generated by the first time slot determining circuit116.

As can be appreciated from the foregoing descriptions, the transmission slot indication signal210, the transmission slot indication signal220, and the transmission slot indication signal230generated by the first time slot determining circuit116based on the second count value CV2respectively correspond to different transmission events, and can be respectively employed to configure the timing of the first transmission slot201, the second transmission slot205, and the third transmission slot209.

In above situation, a first slot interval P1between the first transmission slot201and the second transmission slot205is the same as a second slot interval P2between the second transmission slot205and the third transmission slot209.

In addition, as shown in the upper part ofFIG.2throughFIG.7, in each transmission slot, the first time slot determining circuit116may further generate a corresponding switch signal when the second count value CV2reaches a predetermined value, so as to instruct the transceiver circuit120to switch to a different frequency or a different channel to conduct the Bluetooth signal transmission.

For example, in the first transmission slot201, when the second count value CV2reaches a first target value, the first time slot determining circuit116may generate a switch signal212to instruct the transceiver circuit120to switch to a different frequency or a different channel to conduct the Bluetooth signal transmission.

For another example, in the second transmission slot205, when the second count value CV2reaches a second target value, the first time slot determining circuit116may generate a switch signal222to instruct the transceiver circuit120to switch to a different frequency or a different channel to conduct the Bluetooth signal transmission.

For another example, in the third transmission slot209, when the second count value CV2reaches a third target value, the first time slot determining circuit116may generate a switch signal232to instruct the transceiver circuit120to switch to a different frequency or a different channel to conduct the Bluetooth signal transmission.

It can be appreciated from the foregoing descriptions that the switch signal212, the switch signal222, and the switch signal232generated by the first time slot determining circuit116respectively correspond to different transmission events.

In above situation, a time interval between two adjacent transmission events in the first transmission slot201(e.g., the transmission event corresponding to the transmission slot indication signal210and the transmission event corresponding to the switch signal212) is L0; a time interval between two adjacent transmission events in the second transmission slot205(e.g., the transmission event corresponding to the transmission slot indication signal220and the transmission event corresponding to the switch signal222) is L0; and a time interval between two adjacent transmission events in the third transmission slot209(e.g., the transmission event corresponding to the transmission slot indication signal230and the transmission event corresponding to the switch signal232) is also L0.

As described previously, the control circuit140may control the first count value adjusting circuit114to utilize different approaches to generate the second count value CV2in different operation stages of the Bluetooth controller circuit100, and may control the first time slot determining circuit116to utilize different approaches to decide the timing of respective transmission slots.

For example, the control circuit140may instruct the first count value adjusting circuit114to adjust the first count value CV1generated by the first clock counter112to generate a second count value CV2in a predetermined operation stage (e.g., before the Bluetooth controller circuit100conducts Bluetooth pairing with other Bluetooth circuit), so that the magnitude of the second count value CV2intermittently exhibits a non-linear change. In operations, the first count value adjusting circuit114may generate the second count value CV2by intermittently increasing magnitude of the first count value CV1, by intermittently decreasing the magnitude of the first count value CV1, by periodically increasing the magnitude of the first count value CV1, or by periodically decreasing the magnitude of the first count value CV1.

For example, the first count value adjusting circuit114may intermittently add a fixed value, a variable value, or a random value to the first count value CV1to generate the second count value CV2. In this situation, the increment speed of the second count value CV2is faster than that of the first count value CV1, and the time point at which the second count value CV2reaches a certain value will be advanced in comparison with the original case.

For another example, the first count value adjusting circuit114may intermittently subtract a fixed value, a variable value, or a random value from the first count value CV1to generate the second count value CV2. In this situation, the increment speed of the second count value CV2is slower than that of the first count value CV1, and the time point at which the second count value CV2reaches a certain value will be delayed in comparison with the original case.

For another example, the first count value adjusting circuit114may periodically add a fixed value, a variable value, or a random value to the first count value CV1to generate the second count value CV2. In this situation, the increment speed of the second count value CV2is faster than that of the first count value CV1, and the time point at which the second count value CV2reaches a certain value will be advanced in comparison with the original case.

For another example, the first count value adjusting circuit114may periodically subtract a fixed value, a variable value, or a random value from the first count value CV1to generate the second count value CV2. In this situation, the increment speed of the second count value CV2is slower than that of the first count value CV1, and the time point at which the second count value CV2reaches a certain value will be delayed in comparison with the original case.

In one embodiment, the aforementioned fixed value, variable value, and/or random value is decided by the first count value adjusting circuit114. In another embodiment, the aforementioned fixed value, variable value, and/or random value is configured by the control circuit140.

When adopting the aforementioned approaches, the magnitude of the second count value CV2generated by the first count value adjusting circuit114will not continuously increase steadily. Instead, the magnitude of the second count value CV2will intermittently change non-linearly to exhibit a non-linear change. In operations, the first count value adjusting circuit114may generate the second count value CV2by adopting a hybrid of different approaches described above to thereby adjust the time point at which the second count value CV2reaches a certain value.

As described previously, the first time slot determining circuit116decides the timing of respective transmission slots according to the second count value CV2. Accordingly, when the first count value adjusting circuit114utilizes the aforementioned approaches to adjust the time point at which the second count value CV2reaches a certain value, the first time slot determining circuit116is enabled to adjust the timing of respective transmission slots based on the second count value CV2to cause the interval between adjacent transmission slots to not remain consistency.

For example, the first count value adjusting circuit114may adopt various approaches described previously to make the second count value CV2to reach a specific value in advance. In this situation, the first time slot determining circuit116is enabled to advance the timing of a specific transmission slot according to the second count value CV2.

For another example, the first count value adjusting circuit114may adopt various approaches described previously to postpone the time point at which the second count value CV2reaches a specific value. In this situation, the first time slot determining circuit116is enabled to delay the timing of a specific transmission slot according to the second count value CV2.

Since the magnitude of the second count value CV2intermittently exhibits a non-linear change, the first time slot determining circuit116may adjust the timing of different transmission slots differently to ensure that the time intervals between adjacent transmission slots do not maintain consistency.

In addition, when the first count value adjusting circuit114adopts the aforementioned approaches to adjust the time point at which the second count value CV2reaches a specific value, the first time slot determining circuit116may further adjust the generation timing of respective switch signals in a specific transmission slot according to the second count value CV2to adjust the trigger timing of respective transmission events, to thereby cause the intervals between adjacent transmission events in the specific transmission slot to not remain consistency.

For example, the first count value adjusting circuit114may adopt various approaches described previously to make the second count value CV2to reach a specific value in advance. In this situation, the first time slot determining circuit116is enabled to advance the generation timing of one or more switch signals to thereby advance the trigger timing of one or more corresponding transmission events.

For another example, the first count value adjusting circuit114may adopt various approaches described previously to postpone the time point at which the second count value CV2reaches a specific value. In this situation, the first time slot determining circuit116is enabled to delay the generation timing of one or more switch signals to thereby delay the trigger timing of one or more corresponding transmission events.

Since the magnitude of the second count value CV2intermittently exhibits a non-linear change, the first time slot determining circuit116may adjust the trigger timing of different transmission events differently to ensure that the time intervals between adjacent transmission events in the same transmission slot do not maintain consistency.

Different embodiments ofFIG.2throughFIG.7will be further described in the following.

In the embodiment ofFIG.2, the first time slot determining circuit116also generates the transmission slot indication signal210according to the second count value CV2at the first time point T1, and also generates the transmission slot indication signal230according to the second count value CV2at the third time point T3. Accordingly, in comparison with the original case, the first time slot determining circuit116does not change the timing of the first transmission slot201and the timing of the third transmission slot209.

However, the first time slot determining circuit116generates the transmission slot indication signal220according to the second count value CV2at a fourth time point T4prior to the second time point T2in the embodiment ofFIG.2. As a result, the first time slot determining circuit116advances the timing of the second transmission slot205in comparison with the original case.

In this situation, a first adjusted slot interval P1′ between the first transmission slot201and the second transmission slot205will be shorter than the first slot interval P1of the original case, and a second adjusted slot interval P2′ between the second transmission slot205and the third transmission slot209will be longer than the first adjusted slot interval P1′ of the original case.

Accordingly, the original periodic relationship of a plurality of transmission slots (for example, the first transmission slot201, the second transmission slot205, and the third transmission slot209) can destroyed by adopting the transmission slot timing adjusting method ofFIG.2.

Additionally, in the embodiment ofFIG.2, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal212) in the first transmission slot201according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the first transmission slot201(i.e., the transmission event corresponding to the transmission slot indication signal210and the transmission event corresponding to the switch signal212) from L0to be L1.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal222) in the second transmission slot205according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the second transmission slot205(i.e., the transmission event corresponding to the transmission slot indication signal220and the transmission event corresponding to the switch signal222) from L0to be L2.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal232) in the third transmission slot209according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the third transmission slot209(i.e., the transmission event corresponding to the transmission slot indication signal230and the transmission event corresponding to the switch signal232) from L0to be L3. In practice, the aforementioned time interval L1, time interval L2, and time interval L3may be different from each other.

In the embodiment ofFIG.3, the first time slot determining circuit116also generates the transmission slot indication signal210according to the second count value CV2at the first time point T1. Accordingly, in comparison with the original case, the first time slot determining circuit116does not change the timing of the first transmission slot201.

However, the first time slot determining circuit116of the embodiment ofFIG.3generates the transmission slot indication signal220according to the second count value CV2at a fourth time point T4prior to the second time point T2, and generates the transmission slot indication signal230according to the second count value CV2at a fifth time point T5prior to the third time point T3. As a result, the first time slot determining circuit116advances the timing of the second transmission slot205and the third transmission slot209in comparison with the original case, but the adjustment amount of the timing of the second transmission slot205and the adjustment amount of the timing of the third transmission time slot209are not required to restricted be the same.

In this situation, the first adjusted slot interval P1′ between the first transmission slot201and the second transmission slot205will be shorter than the first slot interval P1of the original case, while the second adjusted slot interval P2′ between the second transmission slot205and the third transmission slot209may be longer than or shorter than the first adjusted slot interval P1.

Accordingly, the original periodic relationship of a plurality of transmission slots (for example, the first transmission slot201, the second transmission slot205, and the third transmission slot209) can destroyed by adopting the transmission slot timing adjusting method ofFIG.3.

Additionally, in the embodiment ofFIG.3, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal212) in the first transmission slot201according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the first transmission slot201(i.e., the transmission event corresponding to the transmission slot indication signal210and the transmission event corresponding to the switch signal212) from L0to be L1.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal222) in the second transmission slot205according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the second transmission slot205(i.e., the transmission event corresponding to the transmission slot indication signal220and the transmission event corresponding to the switch signal222) from L0to be L2.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal232) in the third transmission slot209according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the third transmission slot209(i.e., the transmission event corresponding to the transmission slot indication signal230and the transmission event corresponding to the switch signal232) from L0to be L3. In practice, the aforementioned time interval L1, time interval L2, and time interval L3may be different from each other.

In the embodiment ofFIG.4, the first time slot determining circuit116also generates the transmission slot indication signal210according to the second count value CV2at the first time point T1. Accordingly, in comparison with the original case, the first time slot determining circuit116does not change the timing of the first transmission slot201.

However, the first time slot determining circuit116of the embodiment ofFIG.4generates the transmission slot indication signal220according to the second count value CV2at the fourth time point T4prior to the second time point T2, and generates the transmission slot indication signal230according to the second count value CV2at a sixth time point T6after the third time point T3. As a result, the first time slot determining circuit116advances the timing of the second transmission slot205and postpones the timing of the third transmission slot209in comparison with the original case.

In this situation, the first adjusted slot interval P1′ between the first transmission slot201and the second transmission slot205will be shorter than the first slot interval P1of the original case, while the second adjusted slot interval P2′ between the second transmission slot205and the third transmission slot209will be longer than the first adjusted slot interval P1.

Accordingly, the original periodic relationship of a plurality of transmission slots (for example, the first transmission slot201, the second transmission slot205, and the third transmission slot209) can destroyed by adopting the transmission slot timing adjusting method ofFIG.4.

Additionally, in the embodiment ofFIG.4, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal212) in the first transmission slot201according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the first transmission slot201(i.e., the transmission event corresponding to the transmission slot indication signal210and the transmission event corresponding to the switch signal212) from L0to be L1.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal222) in the second transmission slot205according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the second transmission slot205(i.e., the transmission event corresponding to the transmission slot indication signal220and the transmission event corresponding to the switch signal222) from L0to be L2.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal232) in the third transmission slot209according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the third transmission slot209(i.e., the transmission event corresponding to the transmission slot indication signal230and the transmission event corresponding to the switch signal232) from L0to be L3. In practice, the aforementioned time interval L1, time interval L2, and time interval L3may be different from each other.

In the embodiment ofFIG.5, the first time slot determining circuit116also generates the transmission slot indication signal210according to the second count value CV2at the first time point T1, and also generates the transmission slot indication signal230according to the second count value CV2at the third time point T3. Accordingly, in comparison with the original case, the first time slot determining circuit116does not change the timing of the first transmission slot201and the timing of the third transmission slot209.

However, the first time slot determining circuit116generates the transmission slot indication signal220according to the second count value CV2at a seventh time point T4after the second time point T2in the embodiment ofFIG.5. As a result, the first time slot determining circuit116postpones the timing of the second transmission slot205in comparison with the original case.

In this situation, the first adjusted slot interval P1′ between the first transmission slot201and the second transmission slot205will be longer than the first slot interval P1of the original case, and a second adjusted slot interval P2′ between the second transmission slot205and the third transmission slot209will be shorter than the first adjusted slot interval P1′ of the original case.

Accordingly, the original periodic relationship of a plurality of transmission slots (for example, the first transmission slot201, the second transmission slot205, and the third transmission slot209) can destroyed by adopting the transmission slot timing adjusting method ofFIG.5.

Additionally, in the embodiment ofFIG.5, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal212) in the first transmission slot201according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the first transmission slot201(i.e., the transmission event corresponding to the transmission slot indication signal210and the transmission event corresponding to the switch signal212) from L0to be L1.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal222) in the second transmission slot205according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the second transmission slot205(i.e., the transmission event corresponding to the transmission slot indication signal220and the transmission event corresponding to the switch signal222) from L0to be L2.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal232) in the third transmission slot209according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the third transmission slot209(i.e., the transmission event corresponding to the transmission slot indication signal230and the transmission event corresponding to the switch signal232) from L0to be L3. In practice, the aforementioned time interval L1, time interval L2, and time interval L3may be different from each other.

In the embodiment ofFIG.6, the first time slot determining circuit116also generates the transmission slot indication signal210according to the second count value CV2at the first time point T1. Accordingly, in comparison with the original case, the first time slot determining circuit116does not change the timing of the first transmission slot201.

However, the first time slot determining circuit116of the embodiment ofFIG.6generates the transmission slot indication signal220according to the second count value CV2at the seventh time point T7after the second time point T2, and generates the transmission slot indication signal230according to the second count value CV2at the sixth time point T6after the third time point T3. As a result, the first time slot determining circuit116postpones the timing of the second transmission slot205and the third transmission slot209in comparison with the original case, but the adjustment amount of the timing of the second transmission slot205and the adjustment amount of the timing of the third transmission time slot209are not required to restricted be the same.

In this situation, the first adjusted slot interval P1′ between the first transmission slot201and the second transmission slot205will be longer than the first slot interval P1of the original case, while the second adjusted slot interval P2′ between the second transmission slot205and the third transmission slot209may be longer than or shorter than the first adjusted slot interval P1.

Accordingly, the original periodic relationship of a plurality of transmission slots (for example, the first transmission slot201, the second transmission slot205, and the third transmission slot209) can destroyed by adopting the transmission slot timing adjusting method ofFIG.6.

Additionally, in the embodiment ofFIG.6, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal212) in the first transmission slot201according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the first transmission slot201(i.e., the transmission event corresponding to the transmission slot indication signal210and the transmission event corresponding to the switch signal212) from L0to be L1.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal222) in the second transmission slot205according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the second transmission slot205(i.e., the transmission event corresponding to the transmission slot indication signal220and the transmission event corresponding to the switch signal222) from L0to be L2.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal232) in the third transmission slot209according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the third transmission slot209(i.e., the transmission event corresponding to the transmission slot indication signal230and the transmission event corresponding to the switch signal232) from L0to be L3. In practice, the aforementioned time interval L1, time interval L2, and time interval L3may be different from each other.

In the embodiment ofFIG.7, the first time slot determining circuit116also generates the transmission slot indication signal210according to the second count value CV2at the first time point T1. Accordingly, in comparison with the original case, the first time slot determining circuit116does not change the timing of the first transmission slot201.

However, the first time slot determining circuit116of the embodiment ofFIG.7generates the transmission slot indication signal220according to the second count value CV2at the seventh time point T7after the second time point T2, and generates the transmission slot indication signal230according to the second count value CV2at the fifth time point T5prior to the third time point T3. As a result, the first time slot determining circuit116postpones the timing of the second transmission slot205and advances the timing of the third transmission slot209in comparison with the original case, but the adjustment amount of the timing of the second transmission slot205and the adjustment amount of the timing of the third transmission time slot209are not required to restricted be the same.

In this situation, the first adjusted slot interval P1′ between the first transmission slot201and the second transmission slot205will be longer than the first slot interval P1of the original case, while the second adjusted slot interval P2′ between the second transmission slot205and the third transmission slot209will be shorter than the first adjusted slot interval P1.

Accordingly, the original periodic relationship of a plurality of transmission slots (for example, the first transmission slot201, the second transmission slot205, and the third transmission slot209) can destroyed by adopting the transmission slot timing adjusting method ofFIG.7.

Additionally, in the embodiment ofFIG.7, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal212) in the first transmission slot201according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the first transmission slot201(i.e., the transmission event corresponding to the transmission slot indication signal210and the transmission event corresponding to the switch signal212) from L0to be L1.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal222) in the second transmission slot205according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the second transmission slot205(i.e., the transmission event corresponding to the transmission slot indication signal220and the transmission event corresponding to the switch signal222) from L0to be L2.

Similarly, the first time slot determining circuit116may adjust the generation timing of respective switch signals (e.g., the switch signal232) in the third transmission slot209according to the second count value CV2to advance or delay the trigger timing of related transmission events. In this situation, the first time slot determining circuit116is enabled to adjust the time interval between the first two adjacent transmission events in the third transmission slot209(i.e., the transmission event corresponding to the transmission slot indication signal230and the transmission event corresponding to the switch signal232) from L0to be L3. In practice, the aforementioned time interval L1, time interval L2, and time interval L3may be different from each other.

In the foregoing embodiments ofFIG.2throughFIG.7, the first time slot determining circuit116may advance or postpone the timing of respective transmission slots according to the second count value CV2, and it is not limited that different transmission slots must have the same timing adjusting direction and/or timing adjustment amount. In practice, the first time slot determining circuit116may advance the timing of respective transmission slots by 2% to 19.5% according to the second count value CV2.

For example, the first count value adjusting circuit114may adopt various approaches described previously to adjust the time point at which the second count value CV2reaches a certain value, so that the first time slot determining circuit116can advance the timing of a specific transmission slot by 3.5%, 5%, 7%, 8.5%, 10%, 12%, 15%, 17%, 18.5%, or 19.5%.

Additionally, in the foregoing embodiments ofFIG.2throughFIG.7, the first time slot determining circuit116may advance or postpone the trigger timing of respective transmission events in the same transmission slot according to the second count value CV2, and it is not limited that the trigger timing of different transmission events must have the same adjusting direction and/or adjustment amount. In practice, the first time slot determining circuit116may advance the trigger timing of respective transmission events by 3% to 78% according to the second count value CV2, or may postpone the trigger timing of respective transmission events by 3% to 78% according to the second count value CV2.

For example, the first count value adjusting circuit114may adopt various approaches described previously to adjust the time point at which the second count value CV2reaches a certain value, so that the first time slot determining circuit116can advance or delay the trigger timing of individual transmission event in the same transmission slot by 5%, 7.5%, 10%, 15%, 20%, 25%, 30%, 45%, 50%, 60%, or 75%.

On the other hand, after the Bluetooth controller circuit100completes the Bluetooth pairing operation with other Bluetooth circuit, the control circuit140may instruct the first count value adjusting circuit114to simply utilize the first count value CV1currently generated by the first clock counter112to be the second count value CV2at that time, without adjusting to the first count value CV1.

It can be appreciated from the foregoing descriptions that the first count value adjusting circuit114may adjust the first count value CV1generated by the first clock counter112according to the instruction of the control circuit140to generate the second count value CV2, so that the magnitude of the second count value CV2can intermittently change non-linearly to exhibit a non-linear change.

When the first count value adjusting circuit114adopts the disclosed approaches to adjust the time point at which the second count value CV2reaches a specific value, the first time slot determining circuit116is enabled to adjust the timing of respective transmission slots according to the second count value CV2, to cause the intervals between adjacent transmission slots to not remain consistency.

In addition, when the first count value adjusting circuit114adopts the disclosed approaches to adjust the time point at which the second count value CV2reaches a specific value, the first time slot determining circuit116is enabled to adjust the generation timing of respective switch signals in a specific transmission slot to adjust the trigger timing of respective transmission events, to thereby cause the intervals between adjacent transmission events in the specific transmission slot to not remain consistency.

It can be appreciated from the foregoing descriptions that the disclosed Bluetooth controller circuit100can dynamically adjust the timing of respective transmission slots and/or the trigger timing of respective transmission events, and thus can effectively destroy the periodicity of the Bluetooth packet transmission behavior of the transceiver circuit120.

Since the Bluetooth controller circuit100can destroy the periodicity of the Bluetooth packet transmission behavior, it can effectively reduce the possibility that the Bluetooth controller circuit100or the related Bluetooth communication device in which the Bluetooth controller circuit100is installed generates noises that can be perceived by human ears.

In addition, periodic signals may cause electromagnetic interference (EMI) to peripheral circuits. Therefore, from another aspect, since the Bluetooth controller circuit100can destroy the periodicity of the Bluetooth packet transmission behavior by adopting the aforementioned slot timing adjusting approaches ofFIG.2throughFIG.7, the Bluetooth controller circuit100can also reduce the possibility that the Bluetooth packet transmission behavior of the transceiver circuit120induces EMI to the internal circuits of the Bluetooth controller circuit100or other circuits (e.g., the audio playback circuit104or the sound capturing circuit106).

Please note that the quantity and functionality of the functional blocks of the disclosed Bluetooth controller circuit100may be modified according to the requirement of actual circuit design, and are not restricted to the pattern in the aforementioned embodiments.

For example,FIG.8shows a simplified functional block diagram of a Bluetooth controller circuit800according to a second embodiment of the present disclosure. The Bluetooth controller circuit800is similar to the aforementioned Bluetooth controller circuit100, but the Bluetooth controller circuit800further comprise a second clock counter812, a second count value adjusting circuit814, and a second time slot determining circuit816.

The second clock counter812is arranged to operably generate a third count value CV3corresponding to a reference clock signal CLKR. For example, the second clock counter812may conduct a counting operation based on a specific edge (e.g., the rising edge or the falling edge) of the reference clock signal CLKR to generate a third count value CV3corresponding to the quantity of the specific edge of the reference clock signal CLKR. In general, the reference clock signal CLKR has a stable frequency, and thus the magnitude of the third count value CV3generated by the second clock counter812will increase stably and exhibit a linear change. The second clock counter812may reset the magnitude of the third count value CV3at an appropriate time.

The second count value adjusting circuit814is coupled with the second clock counter812, and arranged to operably generate a fourth count value CV4according to the third count value CV3.

The second time slot determining circuit816is coupled with the second count value adjusting circuit814, and arranged to operably decide the timing of respective transmission slots (TX slots) and the timing of respective reception slots (RX slots) according to the fourth count value CV4.

In the embodiment ofFIG.8, the transceiver circuit120is coupled with the first time slot determining circuit116, and further coupled with the second time slot determining circuit816, and arranged to operably transmit Bluetooth signals in the transmission slots configured by the second time slot determining circuit816, and arranged to operably receive Bluetooth signals in the reception slots configured by the second time slot determining circuit816.

Additionally, the control circuit140in the embodiment ofFIG.8may utilize a second control signal CTL2to control the second count value adjusting circuit814to generate the fourth count value CV4by adopting different approaches in different operation stages of the Bluetooth controller circuit800.

The foregoing descriptions regarding the connection relationships, the implementations, the operations, and related advantages of the first clock counter112, the first count value adjusting circuit114, and the first time slot determining circuit116ofFIG.1are also applicable to the second clock counter812, the second count value adjusting circuit814, and the second time slot determining circuit816ofFIG.8. In addition, the foregoing descriptions regarding the connection relationships, the implementations, the operations, and related advantages of other circuits inFIG.1are also applicable to the embodimentFIG.8. For the sake of brevity, the descriptions will not be repeated here.

The Bluetooth controller circuit800may utilize the cooperation of the first clock counter112, the first count value adjusting circuit114, and the first time slot determining circuit116to dynamically adjust the timing of transmission slots corresponding to a first piconet, while utilize the cooperation of the second clock counter812, the second count value adjusting circuit814, and the second time slot determining circuit816to dynamically adjust the timing of transmission slots corresponding to a second piconet.

In practice, each of the Bluetooth controller circuit100and the Bluetooth controller circuit800may be provided with more sets of circuits with aforementioned slot timing adjustment functionality, so that the Bluetooth controller circuit100and the Bluetooth controller circuit800can apply the disclosed transmission slot timing adjustment mechanism to more piconets at the same time.

In some embodiments where the Bluetooth controller circuit100and the Bluetooth controller circuit800do not need to capture the user's voice or ambient sounds, the sound capturing circuit106may be omitted.

In some embodiments where the Bluetooth controller circuit100and the Bluetooth controller circuit800do not need to play the audio data, the audio playback circuit104may be omitted.

Certain terms are used throughout the description and the claims to refer to particular components. One skilled in the art appreciates that a component may be referred to as different names. This disclosure does not intend to distinguish between components that differ in name but not in function. In the description and in the claims, the term “comprise” is used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to.” The term “couple” is intended to encompass any indirect or direct connection. Accordingly, if this disclosure mentioned that a first device is coupled with a second device, it means that the first device may be directly or indirectly connected to the second device through electrical connections, wireless communications, optical communications, or other signal connections with/without other intermediate devices or connection means.

The term “and/or” may comprise any and all combinations of one or more of the associated listed items. In addition, the singular forms “a,” “an,” and “the” herein are intended to comprise the plural forms as well, unless the context clearly indicates otherwise.