PROTOCOL FOR COMMUNICATION

• US 20130282807A1
• Filed: 04/20/2012
• Published: 10/24/2013
• Est. Priority Date: 04/20/2012
• Status: Active Grant

• Current Assignee: Combined Conditional Access Development & Support LLC
• Original Assignee: Combined Conditional Access Development & Support LLC
• Inventors: Tonthat, An, Rudy, John Edward, Murray, Patrick Charles
• Granted Patent: US 9,569,390 B2
• Time in Patent Office: Days
• US Class Current: 709/204
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices

Abstract

Aspects of the disclosure relate to a protocol for communication of information. The protocol can be a non-standard universal serial bus (USB) protocol and can guarantee bandwidth and latency for information communication between a USB host and a single USB device. In one aspect, the non-standard USB protocol can employ a repeating message sequence that is fixed, or static, and preconfigured, the sequence comprising alternating transmission of messages between a first device (e.g., a host device) and a second device (e.g., a peripheral device).

Claims

1. A method of exchanging messages among a first device and a second device, the method comprising:

(i) transmitting, by the first device, a first message to the second device, the first message having a first fixed length wherein the first fixed length satisfies, at least in part, a bandwidth constraint;

(ii) receiving, at the first device, a second message from the second device in response to transmitting the first message, the second message having the first fixed length.

2. The method of claim 1, further comprising repeating steps (i) and (ii) at least one time.

3. The method of claim 1, further comprising:

(iii) transmitting, by the first device, a third message to the second device in response to receiving the second message, the third message having a second fixed length, wherein the second fixed length fulfills, at least in part, a bandwidth constraint;

(iv) receiving, at the first device, a fourth message from the second device, the fourth message having the second fixed length; and

(v) repeating steps (i) and (ii), (iii), and (iv) at least one time, wherein the first message, the second message, the third message, and the fourth message are serial messages.

4. The method of claim 1, wherein the transmitting step in step (i) comprises transmitting, by the first device, a first transport message to the second device, the first transport message being part of the first message.

5. The method of claim 4, wherein the receiving step in step (ii) comprises receiving, at the first device, a second transport message from the second device, the second transport message being part of the second message.

6. The method of claim 4, wherein transmitting, by the first device, the first message to the second device comprises:

transmitting, as part of the first transport message, a data identifier, a message status identifier, payload data, and reference data, and wherein

the identifier indicates that the first transport message contains transport data or the payload data is null.

7. The method of claim 5, wherein receiving, at the first device, the second transport message from the second device comprises:

receiving, as part of the second transport message, a data identifier, a message status identifier, payload data, and reference data, and wherein

the identifier indicates that the second transport message contains transport data or the payload data is null.

8. The method of claim 5, wherein the transmitting step in step (iii) comprises transmitting, by the first device, a first control message to the second device, the first control message being part of the third message.

9. The method of claim 8, wherein the receiving step in step (iv) comprises receiving, at the first device, a second control message from the second device, the second control message being part of the fourth message.

10. The method of claim 8, wherein transmitting, by the first device, the first control message to the second device comprises transmitting, as part of the first control message, a data identifier, a message status identifier, payload data, and reference data, wherein

the identifier indicates that the first control message contains control data or the payload data is null, and further wherein

the message status identifier conveys a common interface reset instruction, an indication that the first device is ready to receive data, and, in response to the identifier indicating the first control message contains data, an indication of the type of control data.

11. The method of claim 9, wherein receiving, at the first device, the second control message from the second device comprises receiving, as part of the second control message, a data identifier, a message status identifier, payload data, and reference data, and wherein

the identifier indicates that the second control message contains control data or the payload data is null, and further wherein

the message status identifier conveys a common interface reset instruction, an indication that the second device is ready to receive data, and, in response to the identifier indicating the second control message contains data, an indication of the type of control data.

12. The method of claim 9, wherein receiving, at the first device, the second control message from the second device comprises receiving 20 bytes of information as part of the second control message.

13. A method of exchanging messages among devices, the method comprising:

(i) transmitting, by a first device, a first serial message of a first plurality of serial messages to a second device, the first serial message having a first fixed length;

(ii) receiving, at the first device, a second serial message of a second plurality of serial messages from the second device in response to transmitting the first serial message, the second serial message having the first fixed length;

(iii) repeating steps (i) and (ii) until all of the serial messages in the first plurality of serial messages are transmitted;

(iv) transmitting, by the first device, a third serial message of a third plurality of serial messages to the second device, the third serial message having a second fixed length;

(v) receiving, at the first device, a fourth serial message of a fourth plurality of serial messages from the second device in response to transmitting the third serial message, the fourth serial message having the second fixed length; and

(vi) repeating steps (iv) and (v) until all of the serial messages in the third plurality of serial messages is transmitted.

14. The method of claim 13, further comprising (vii) repeating steps (i) through (vi) at least one time.

15. An apparatus, comprising:

a first device; and

a second device functionally coupled to the first device via a serial link,

the first device configured to;

transmit a first serial message to the second device, the first serial message having a first static length determined at least in part by a communication bandwidth constraint, and

receive a second serial message from the second device in response to transmission of the first serial message, the second serial message having a second static length determined at least in part by the communication bandwidth constraint, and

the second device configured to;

receive the first serial message from the first device, and

transmit the second serial message to the first device in response to reception of the first serial message,

the first device being further configured to transmit a third serial message to the second device, the third serial message having the first static length, and

the second device being further configured to transmit a fourth serial message to the first device, the fourth serial message having the second static length.

16. The apparatus of claim 15, wherein the first static length is substantially the same as the second static length.

17. The apparatus of claim 15, wherein the first serial message comprises a first transport message having traffic or null data.

18. The apparatus of claim 15, wherein the second message comprises a second transport message having traffic or null data.

19. The apparatus of claim 15, wherein the second message comprises a data message having control data.

20. The apparatus of claim 15, wherein the serial link is a universal serial bus (USB) cable.