Signaling Between Master and Slave Components Using a Shared Communication Node of the Master Component

• US 20150236746A1
• Filed: 03/12/2015
• Published: 08/20/2015
• Est. Priority Date: 02/18/2014
• Status: Active Grant

• Current Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Original Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Inventors: Scheinkerman, Ricardo, Kozomora, Nevenka, Doogue, Michael C., Vreeland, Richard
• Granted Patent: US 9,634,715 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/00 Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements

Abstract

A network slave device includes a transceiver for communicating over a communication bus in accordance with a point-to-point network protocol. The network slave device may have an address to identify the network slave device on the network. It may also have a communication circuit configured to process a series of commands received by the transceiver and respond to a command if a position of the command in the series of commands corresponds to the address of the network slave device. A master device communicating on the network may send the series of command in accordance with the point-to-point network protocol. In an embodiment, the point-to-point protocol is the SENT protocol.

Claims

1. A network slave device comprising:

a transceiver for communicating over a communication bus in accordance with a point-to-point network protocol;

an address to identify the network slave device; and

a communication circuit configured to process a series of commands received by the transceiver and respond to a command if a position of the command in the series of commands corresponds to the address of the network slave device.

2. The network slave device of claim 1 wherein the point-to-point communication protocol is a SENT protocol.

3. The network slave device of claim 1 further comprising a memory, wherein the address is stored in the memory.

4. The network slave device of claim 1 wherein the slave device comprises a magnetic field sensor.

5. The network slave device of claim 4 wherein the magnetic field sensor comprises magnetic field sensing elements.

6. The network slave device of claim 5 wherein the magnetic field sensing elements Hall effect elements.

7. The network slave device of claim 5 wherein the magnetic field sensing elements comprise magnetoresistive elements.

8. The network slave device of claim 7 wherein the magnetoresistive elements comprise a GMR element, a TMR element, an MTJ element, a spin-valve, or a combination thereof.

9. The network slave device of claim 4 wherein the commands comprise requests for data representing a magnetic field detected by the magnetic field sensor.

10. The network slave device of claim 1 further comprising a counter configured to count the number of commands sent by the master device.

11. The network slave device of claim 10 further configured to respond to a reset command by resetting the counter.

12. The network slave device of claim 10 further configured to reset the counter when a number of commands received meets or exceeds a number of slave devices coupled to the communication bus.

13. The network slave device of claim 1 wherein the commands include one or more of:

a sample command to perform a measurement;

a data request command to send measurement data;

a diagnostic command perform a self-test;

a reset command to reset a counter;

or a combination thereof.

14. The network slave device of claim 13 wherein the sample command comprises a pulse of one predetermined length, the diagnostic command comprises a pulse of a second predetermined length;

the data request command comprises a pulse of a third predetermined length; and

the reset command comprises a pulse of a fourth predetermined length.

15. The network slave device of claim 1 wherein the commands comprise broadcast commands.

16. The network slave device of claim 15 wherein the broadcast commands include one or more of:

a sample command to perform one or more respective measurements;

a diagnostic command to perform one or more respective self-tests;

a reset command to reset a counter of the slave device;

or a combination thereof.

17. The network slave device of claim 1 further configured to delay sending a response to the commands by a delay time period corresponding to the address of the slave device.

18. The network slave device of claim 1 further configured to read a delay time period of a response from another network slave device and determine a current position in the series based on the delay time period.

19. A system comprising:

a master device coupled to a communication bus and configured to communicate over the communication bus in accordance with a point-to-point communication protocol to send a series of commands over the communication bus; and

one or more slave devices coupled to the communication bus to communicate over the communication bus in accordance with the point-to-point communication protocol, each of the slave devices having a respective address to identify the respective slave device and configured to respond to a command in the series of commands that has a position within the series that matches the respective address of the respective slave device.

20. The system of claim 19 wherein the master device and the one or more slave devices are configured to communicate over the communication bus in accordance with a point-to point communication protocol.

21. The system of claim 20 wherein the point-to-point communication protocol is a SENT protocol.

22. The system of claim 19 wherein the one or more slave devices are magnetic field sensors.

23. The system of claim 22 wherein the commands comprise requests for data representing a magnetic field detected by at least one of the magnetic field sensors.

24. The system of claim 19 wherein the one or more slave devices each comprise a counter configured to count the number of commands sent by the master device.

25. The system of claim 24 wherein the master device is configured to send a reset command which, when received by the one or more slave devices, resets the counters of the one or more slave devices.

26. The system of claim 24 wherein each respective slave device is configured to respond to the commands when a counter of the respective slave device matches the address of the respective slave device.

27. The system of claim 24 wherein the one or more slave devices are configured to reset their counters when a number of commands sent by the master device matches or exceeds a number of slave devices coupled to the communication bus.

28. The system of claim 19 wherein the commands include one or more of:

a sample command to perform a measurement;

a diagnostic command perform a self-test; and

a reset command to reset a counter.

29. The system of claim 28 wherein the sample command comprises a pulse of one predetermined length, the diagnostic command comprises a pulse of a second predetermined length;

and the reset command comprises a pulse of a third predetermined length.

30. The system of claim 19 wherein the master device is further configured to send broadcast commands to all the slave devices coupled to the communication bus.

31. The system of claim 30 wherein the broadcast commands comprise commands that do not include an address.

32. The system of claim 30 wherein the broadcast commands include one or more of:

a sample command instructing all the respective slave devices to perform one or more respective measurements;

a diagnostic command instructing all the respective slave devices to perform one or more respective self-tests; and

a reset command instructing all the respective slave device to reset respective counters of the respective slave devices.

33. The system of claim 19 wherein the slave devices are configured to delay sending a response to the commands by a time period corresponding to the address of the slave device.

34. The system of claim 19 wherein the slave devices are configured to read a delay time period of a response from another slave device and determine a current position in the series based on the delay time period.

35. A method comprising:

sending a series of commands by a master device coupled to a one-wire communication bus; and

responding to one of the commands, by a selected slave device, if the position of the command in the series of commands matches an address of the selected slave device.

36. The method of claim 35 wherein the master device and the one or more slave devices are configured to communicate over the communication bus in accordance with a point-to point communication protocol.

37. The method of claim 36 wherein the point-to-point communication protocol is a SENT protocol.

38. The method of claim 35 wherein the one or more slave devices are magnetic field sensors.

39. The method of claim 38 wherein sending the series of commands comprises sending requests for data representing a magnetic field detected by at least one of the magnetic field sensors.

40. The method of claim 35 further comprising counting the commands by the one or more slave devices coupled to the communication bus;

41. The method of claim 40 wherein counting the commands comprises incrementing respective counters of the one or more slave devices.

42. The method of claim 35 further comprising sending, by the master device a reset command which, when received by the one or more slave devices, resets the respective counters.

43. The method of claim 42 further comprising restarting the count a number of commands sent by the master device matches or exceeds a number of slave devices coupled to the communication bus.

44. The method of claim 35 wherein the sending the commands include sending one or more of:

a sample command to perform a measurement;

a data request command to send measurement data;

a diagnostic command to perform a self-test; and

a reset command to reset a counter.

45. The method of claim 44 wherein sending the sample command comprises sending a pulse of one predetermined length, sending the diagnostic command comprises sending a pulse of a second predetermined length;

sending the data request command comprises sending a pulse of a third predetermined length; and

sending the reset command comprises sending a pulse of a fourth predetermined length.

46. The method of claim 35 further comprising sending broadcast commands to all the slave devices coupled to the communication bus.

47. The method of claim 46 wherein the broadcast commands comprise commands that do not include an address.

48. The method of claim 46 wherein sending the broadcast commands includes sending one or more of:

a sample command instructing all the respective slave devices to perform one or more respective measurements;

a diagnostic command instructing all the respective slave devices to perform one or more respective self-tests; and

a reset command instructing all the respective slave device to reset respective counters of the respective slave devices.

49. The method of claim 35 wherein responding comprises delaying sending a response to the commands by a delay time period corresponding to the address of the slave device.

50. The method of claim 35 further comprising reading, by the network slave device, a delay time period of a response from another network slave device and determining a current position in the series based on the delay time period.