SYSTEMS AND METHODS OF SELECTIVE OUTPUT FOR REDUCING POWER

• US 20160094768A1
• Filed: 04/04/2015
• Published: 03/31/2016
• Est. Priority Date: 09/29/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: OVSIANNIKOV, Ilia, WANG, Hongyu
• Granted Patent: US 9,967,500 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04N 25/47 Image sensors with pixel address output; Event-driven image sensors; Selection of pixels to be read out based on image data
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array

Abstract

An embodiment includes a system, comprising: a buffer configured to store a plurality of events, each event including a plurality of bits; an output circuit configured to output events from the buffer; and a controller coupled to the buffer and the output circuit and configured to: cause the output circuit to output a first event from the buffer; and select a second event from the buffer to be output by the output circuit after the first event based on bits associated with the first event.

Claims

1. A system, comprising:

a buffer configured to store a plurality of events, each event including a plurality of bits;

an output circuit configured to output events from the buffer; and

a controller coupled to the buffer and the output circuit and configured to;

cause the output circuit to output a first event from the buffer; and

select a second event from the buffer to be output by the output circuit after the first event based on bits associated with the first event.

2. The system of claim 1, further comprising a sensor coupled to the buffer and configured to generate events to be stored in the buffer.

3. The system of claim 2, wherein the sensor comprises a dynamic vision sensor.

4. The system of claim 2, wherein each event generated by the sensor comprises an address of a pixel of the sensor and a value associated with a change sensed by the pixel.

5. The system of claim 4, wherein addresses of pixels of the sensor are encoded to reduce a Hamming distance between addresses of substantially adjacent pixels.

6. The system of claim 5, wherein addresses of the pixels of the sensor are encoded with a grey code.

7. The system of claim 1, wherein the controller is configured to select as the second event an event having a minimum Hamming distance to the first event.

8. The system of claim 1, wherein the controller is configured to select the second event such that output of the second event by the output circuit after output of the first event uses a relative minimum of energy relative other events stored in the buffer.

9. The system of claim 1, wherein the buffer has a depth of at least eight events.

10. The system of claim 1, wherein controller comprises:

a comparator configured to compare the first event with at least two events stored in the buffer to determine the second event;

a multiplexer configured to select the second event as the event to be output by the output circuit; and

a demultiplexer configured to select a location in the buffer to store a new event in response to the comparator.

11. The system of claim 1, wherein:

the controller comprises a comparator configured to compare the first event with at least two entries stored in the buffer to determine the second event; and

the buffer is configured to shift entries of the events in response to the comparator.

12. A system, comprising:

a buffer configured to store a plurality of events;

an output circuit configured to output events in the buffer; and

a controller coupled to the buffer and the output circuit and configured to order a sequential output of the events through the output circuit based on adjacent events.

13. The system of claim 12, wherein the controller is configured to select an order of output for the events in the buffer such that for at least two of the events, the sequential output of the at least two events has a minimum number of transitions.

14. The system of claim 13, wherein the controller is configured to select an order of output for the events in the buffer such that the sequential output of the events has a minimum number of transitions.

15. A method, comprising:

storing a plurality of events in a buffer, each event being associated with a corresponding plurality of bits;

outputting a first event of the events in the buffer;

selecting a second event of the events in the buffer to output based on the first event; and

outputting the second event.

16. The method of claim 15, wherein selecting the second event of the events in the buffer comprises:

calculating a Hamming distance between the first event and the events in the buffer; and

selecting one of the events in the buffer with a lowest Hamming distance to the first event as the second event.

17. The method of claim 15, further comprising:

sensing a change in an input to a pixel of a sensor; and

storing an event in the buffer based on the change in the input to the pixel.

18. The method of claim 17, wherein storing the event in the buffer comprises storing an address of the pixel of the sensor and a value associated with the change in the input to the pixel.

19. The method of claim 18, further comprising encoding addresses of pixels of the sensor to reduce a Hamming distance between addresses of substantially adjacent pixels.

20. The method of claim 15, further comprising selecting an output order for at least two events in the buffer such that a number of transitions on output of the at least two events is a minimum.