Asynchronous ID generation

• US 20070234071A1
• Filed: 09/15/2006
• Published: 10/04/2007
• Est. Priority Date: 03/28/2006
• Status: Active Grant

• Current Assignee: Mosaid Technologies Incorporated (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: Mosaid Technologies Incorporated (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Inventors: Pyeon, Hong Beom
• Granted Patent: US 8,364,861 B2
• Time in Patent Office: Days
• US Class Current: 713/190
• CPC Class Codes: G06F 12/0669 with decentralised address assignment
• CPC Class Codes: G06F 13/4247 on a daisy chain bus

Abstract

A technique for automatically establishing device IDs for devices in a daisy chain cascade arrangement. For each device, a write ID operation is initiated at the device to cause the device to enter a generate/write ID mode. While in this mode, a first value is input to the device. The device generates a second value from the first value. The device outputs the generated second value from the device to a next device in the daisy chain cascade which uses the second value as a first value for the next device. The device then establishes its ID from the first value. The process is repeated for all devices in the daisy chain cascade arrangement.

Claims

1. A method of establishing an identifier (ID) for a device configured in a daisy chain cascade arrangement having a plurality of devices, the method comprising:

inputting a first value to a first device in the daisy chain cascade;

outputting a second value generated from the first value from the first device to a second device in the daisy chain cascade via one or more outputs of the first device; and

establishing an ID for the first device from the first value.

2. A method as defined in claim 1 wherein inputting a first value to a first device includes acquiring the state of inputs of the first device.

3. A method as defined in claim 1 wherein establishing an ID for the first device includes placing the first value in storage associated with the first device.

4. A method as defined in claim 3 wherein the storage is a device ID register for the first device.

5. A method as defined in claim 1 wherein the ID is established in response to a command input into the first device.

6. A method as defined in claim 1 wherein the ID is established in response to a control signal that is asserted at an input of the first device.

7. A method as defined in claim 1 further comprising:

adding a predetermined value to the first value to generate the second value.

8. A device configured in a daisy chain cascade arrangement having a plurality of devices, the device comprising:

input circuitry configured to input a first value into the device;

output circuitry configured to output a second value generated from the first value to a second device in the daisy chain cascade via one or more outputs of the device; and

circuitry configured to establish an identifier (ID) for the device from the first value.

9. A device as defined in claim 8 wherein the input circuitry configured to input the first value further comprises circuitry configured to acquire the state of inputs of the first device.

10. A device as defined in claim 8 wherein the circuitry configured to establish the ID for the device further comprises storage and circuitry configured to establish the ID for the device by placing the acquired state in the storage.

11. A device as defined in claim 8 further comprising:

adder circuitry configured to add a third value to the first value to generate the second value.

12. A device as defined in claim 11 wherein the third value is a predetermined value.

13. A device as defined in claim 8 wherein the output circuitry includes:

one or more output buffers configured to output the value to the second device in the daisy chain cascade.

14. A device as defined in claim 8 wherein the second value is generated in response to inputting a command into an input of the first device.

15. A device as defined in claim 8 wherein the value is generated in response to inputting a control signal into an input of the first device.

16. An apparatus for establishing an identifier (ID) for a device configured in a daisy chain cascade arrangement having a plurality of devices, the apparatus comprising:

means for inputting a first value to a first device in the daisy chain cascade;

means for outputting a second value generated from the first value from the first device to a second device in the daisy chain cascade via one or more outputs of the first device; and

means for establishing an ID for the first device from the first value.

17. An apparatus as defined in claim 16 wherein the means for inputting a first value to a first device includes means for acquiring the state of inputs of the first device.

18. An apparatus as defined in claim 16 wherein the means establishing an ID for the first device includes means for placing the first value in storage associated with the first device.

19. An apparatus as defined in claim 16 wherein the ID is established in response to a command input into the first device.

20. An apparatus as defined in claim 16 wherein the ID is established in response to a control signal that is asserted at an input of the first device.

21. An apparatus as defined in claim 16 further comprising:

means for adding a predetermined value to the first value to generate the second value.