One-wire bidirectional bus signaling with manchester encoding

1. A method of data communication performed at a bus master device, comprising:

determining that a first sequence start condition (SSC) has been initiated when a single-wire serial bus has transitioned from a first signaling state to a second signaling state;

causing a line driver to drive the single-wire serial bus from the second signaling state to the first signaling state after a first duration, thereby completing the first SSC;

providing an arbitration window that comprises a plurality of timeslots by causing the line driver to present a high impedance to the single-wire serial bus after the first SSC is completed;

causing the line driver to drive the single-wire serial bus to the first signaling state in each timeslot in the plurality of timeslots in which the single-wire serial bus is driven to the second signaling state;

transmitting a second SSC after the arbitration window is expired; and

transmitting a command addressed to at least one slave device after transmitting the second SSC, the command being encoded using Manchester encoding.

2. The method of claim 1 , wherein the command is formatted in accordance with a Radio Frequency Front-End (RFFE) protocol.

3. The method of claim 1 , further comprising:

initiating the first SSC by causing the line driver to drive the single-wire serial bus to the second signaling state to terminate an idle state of the single-wire serial bus.

4. The method of claim 1 , wherein the second SSC has a second duration that is different from the first duration.

5. The method of claim 1 , wherein a keeper circuit coupled to the single-wire serial bus is operable to maintain signaling state of the single-wire serial bus when the single-wire serial bus is undriven.

6. The method of claim 1 , further comprising:

providing one or more synchronization pulses on the single-wire serial bus after terminating the first SSC.

7. The method of claim 1 , further comprising:

providing one or more synchronization pulses on the single-wire serial bus after transmitting the second SSC.

8. The method of claim 1 , further comprising transmitting a Manchester encoded data payload over the single-wire serial bus when the command comprises a write command.

9. The method of claim 1 , further comprising receiving a Manchester encoded data payload from the single-wire serial bus when the command comprises a read command.

10. The method of claim 9 , further comprising:

providing a line turnaround interval by causing the line driver to present a high impedance to the single-wire serial bus after transmitting the command;

synchronizing an internal clock signal using one or more synchronization pulses received from the single-wire serial bus after the line turnaround interval; and

maintaining synchronization of phase or frequency of the internal clock signal based on transitions in the Manchester encoded data payload.

11. A data communication apparatus, comprising:

a line driver configured to couple the data communication apparatus to a single-wire serial bus; and

a protocol controller configured to:

determine that a first sequence start condition (SSC) has been initiated when the single-wire serial bus has transitioned from a first signaling state to a second signaling state;

cause the line driver to drive the single-wire serial bus from the second signaling state to the first signaling state after a first duration, thereby completing the first SSC;

provide an arbitration window that comprises a plurality of timeslots by causing the line driver to present a high impedance to the single-wire serial bus after the first SSC is completed;

cause the line driver to drive the single-wire serial bus to the first signaling state in each timeslot in the plurality of timeslots in which the single-wire serial bus is driven to the second signaling state;

transmit a second SSC after the arbitration window is expired; and

transmit a command addressed to at least one slave device after transmitting the second SSC, the command being encoded using Manchester encoding.

12. The data communication apparatus of claim 11 , further comprising:

a keeper circuit coupled to the single-wire serial bus and operable to maintain signaling state of the single-wire serial bus when the single-wire serial bus is undriven.

13. The data communication apparatus of claim 11 , wherein the protocol controller is further configured to:

initiate the first SSC by causing the line driver to drive the single-wire serial bus to the second signaling state to terminate an idle state of the single-wire serial bus;

provide one or more synchronization pulses on the single-wire serial bus after terminating the first SSC; and

provide one or more additional synchronization pulses on the single-wire serial bus after transmitting the second SSC.

14. The data communication apparatus of claim 11 , wherein the protocol controller is further configured to:

transmit a Manchester encoded data payload over the single-wire serial bus when the command comprises a write command formatted in accordance with a Radio Frequency Front-End (RFFE) protocol.

15. The data communication apparatus of claim 11 , wherein the protocol controller is further configured to:

provide a line turnaround interval by causing the line driver to present a high impedance to the single-wire serial bus after transmitting the command;

synchronize an internal clock signal using one or more synchronization pulses received from the single-wire serial bus after the line turnaround interval;

receive a Manchester encoded data payload from the single-wire serial bus when the command comprises a read command formatted in accordance with an RFFE protocol; and

maintain synchronization of phase or frequency of the internal clock signal based on transitions in the Manchester encoded data payload.

16. A method of data communication performed at a slave device, comprising:

determining a duration of a first pulse on a single-wire serial bus;

driving the single-wire serial bus from a first signaling state to a second signaling state through initiating a second pulse during a timeslot associated with the slave device in an arbitration window that follows the first pulse on the single-wire serial bus when the first pulse has a first duration that corresponds to a first type of sequence start condition (SSC);

presenting a high impedance to the single-wire serial bus after initiating the second pulse;

receiving a Manchester encoded command from a bus master device over the single-wire serial bus when the first pulse has a second duration that corresponds to a second type of SSC; and

responding to the command when the command is addressed to the slave device.

17. The method of claim 16 , wherein the command is formatted in accordance with a Radio Frequency Front-End (RFFE) protocol.

18. The method of claim 16 , further comprising:

synchronizing a clock signal generated by the slave device based on transitions in one or more synchronization pulses received from the single-wire serial bus after each SSC received over the single-wire serial bus.

19. The method of claim 16 , further comprising:

synchronizing phase or frequency of a clock signal generated by the slave device based on transitions in the Manchester encoded command or in a Manchester encoded data payload received from the single-wire serial bus.

20. The method of claim 16 , further comprising:

receiving a Manchester encoded data payload from the single-wire serial bus when the command comprises a write command; and

decoding the Manchester encoded data payload.

21. The method of claim 16 , further comprising transmitting a Manchester encoded data payload over the single-wire serial bus when the command comprises a read command.

22. The method of claim 21 , further comprising:

transmitting one or more synchronization pulses over the single-wire serial bus prior to transmitting the Manchester encoded data payload.

23. A data communication apparatus, comprising:

a line driver configured to couple the data communication apparatus to a single-wire serial bus; and

a protocol controller configured to:

determine a duration of a first pulse on the single-wire serial bus;

drive the single-wire serial bus from a first signaling state to a second signaling state through initiating a second pulse during a timeslot associated with the data communication apparatus in an arbitration window that follows the first pulse on the single-wire serial bus when the first pulse has a first duration that corresponds to a first type of sequence start condition (SSC);

present a high impedance to the single-wire serial bus after initiating the second pulse;

receive a Manchester encoded command from a bus master device over the single-wire serial bus when the first pulse has a second duration that corresponds to a second type of SSC; and

respond to the command when the command is addressed to the data communication apparatus.

24. The data communication apparatus of claim 23 , wherein the protocol controller is further configured to:

synchronize a clock signal generated by the data communication apparatus based on transitions in one or more synchronization pulses received from the single-wire serial bus after each SSC received over the single-wire serial bus.

25. The data communication apparatus of claim 23 , wherein the protocol controller is further configured to:

receive a Manchester encoded data payload from the single-wire serial bus when the command comprises a write command; and

decode the Manchester encoded data payload.

26. The data communication apparatus of claim 23 , wherein the protocol controller is further configured to:

transmit a Manchester encoded data payload over the single-wire serial bus when the command comprises a read command.

27. The data communication apparatus of claim 26 , wherein the protocol controller is further configured to:

transmit one or more synchronization pulses over the single-wire serial bus prior to transmitting the Manchester encoded data payload.