Andrew Cheung

US Patent:

20180181364, Jun 28, 2018

Filed:

Feb 21, 2018

Appl. No.:

15/900881

Inventors:

- San Diego CA, US
Andrew Cheung - Escondido CA, US
Ameya Kulkarni - San Diego CA, US
Hemant Kumar - San Diego CA, US

International Classification:

G06F 3/16
G06F 13/38

Abstract:

Systems and methods for using distributed Universal Serial Bus (USB) host drivers are disclosed. In one aspect, USB packet processing that was historically done on an application processor is moved to a distributed USB driver running in parallel on a low-power processor such as a digital signal processor (DSP). While a DSP is particularly contemplated, other processors may also be used. Further, a communication path is provided from the low-power processor to USB hardware that bypasses the application processor. Bypassing the application processor in this fashion allows the application processor to remain in a sleep mode for longer periods of time instead of processing digital data received from the low-power processor or the USB hardware. Further, by bypassing the application processor, latency is reduced, which improves the user experience.

US Patent:

20170371681, Dec 28, 2017

Filed:

Jun 23, 2017

Appl. No.:

15/631088

Inventors:

- San Diego CA, US
Andrew Cheung - Escondido CA, US
Jay Yu Jae Choi - San Diego CA, US
Daniel Hyongkyu Kim - San Diego CA, US
Hemant Kumar - San Diego CA, US
Vamsi Krishna Samavedam - San Diego CA, US

International Classification:

G06F 9/44
G06F 3/16
H04L 29/06

Abstract:

Systems and methods for using distributed Universal Serial Bus (USB) host drivers are disclosed. In one aspect, USB packet processing that was historically done on an application processor is moved to a distributed USB driver running in parallel on a low-power processor such as a digital signal processor (DSP). While a DSP is particularly contemplated, other processors may also be used. Further, a communication path is provided from the low-power processor to USB hardware that bypasses the application processor. Bypassing the application processor in this fashion allows the application processor to remain in a sleep mode for longer periods of time instead of processing digital data received from the low-power processor or the USB hardware. Further, by bypassing the application processor, latency is reduced, which improves the listener experience.

US Patent:

20170373881, Dec 28, 2017

Filed:

Jun 23, 2017

Appl. No.:

15/631807

Inventors:

- San Diego CA, US
Andrew Cheung - Escondido CA, US
Ameya Kulkarni - San Diego CA, US

International Classification:

H04L 12/40
H04L 12/931
H04L 12/28

Abstract:

Systems and methods for controlling isochronous data streams are disclosed. Particular aspects of the present disclosure are designed to be used with almost any isochronous data stream, but are well-suited for use with the Universal Serial Bus (USB) protocol. Further, aspects of the present disclosure are flexible to accommodate existing configuration possibilities within the USB protocol as well as accommodate proposed future changes in the USB protocol. The flexibility of the systems and methods is provided by calculating: (1) drift between a USB host system time and the application and (2) drift between the USB host system and a USB device clock. Based on these two drift calculations, a time stamp may be synthesized to program a next delivery schedule. Using this time stamp, jitter correction can take place and uniformly-sized packets may be assembled to pass to an application processor.