Syed R Raza

US Patent:

57606560, Jun 2, 1998

Filed:

Dec 17, 1996

Appl. No.:

8/768154

Inventors:

Richard N. Sutliff - Hampshire IL
Syed S. Raza - Hoffman Estates IL
Matthias F. Laurich - Elgin IL
Vladimir Telemaque - Hoffman Estates IL

Assignee:

Motorola Inc. - Schaumburg IL

International Classification:

H03L 102
H03L 500

US Classification:

331116R

Abstract:

A temperature compensation circuit (10) for a crystal oscillator module (12) used in a communication device (200). An existing microcontroller (210) of the communication device (200) is used to provide temperature compensating digital data (30) for a crystal oscillator (18). In this way, the crystal oscillator module (12) does not require an on-board memory which substantially cuts costs. The temperature compensation digital data (30) is converted to a temperature compensation signal (22) in a digital-to-analog converter which controls the crystal oscillator frequency. However, typical digital-to-analog converters are driven by voltage regulators which vary over temperature. To solve this problem, the crystal oscillator module (12) includes an on-board voltage regulator (34) which supplies a characterized regulated voltage (36) to the digital-to-analog converter such that the temperature compensation signal (22) from the digital-to-analog converter is inherently corrected for voltage variations in the voltage regulator (34). This improves stability of the output frequency (20) from about 5 ppm to about 2 ppm.

US Patent:

20180314547, Nov 1, 2018

Filed:

Apr 26, 2017

Appl. No.:

15/497482

Inventors:

- Redmond WA, US
Mehmet Iyigun - Kirkland WA, US
Christopher Peter Kleynhans - Bellevue WA, US
Syed A. Raza - Chicago IL, US

Assignee:

Microsoft Technology Licensing, LLC - Redmond WA

International Classification:

G06F 9/48
G06F 9/50

Abstract:

The threads of a user mode process can access various different resources of a computing device, and such access can be serialized. To access a serialized resource, a thread acquires a lock for the resource. For each context switch in the computing device, a module of the operating system kernel checks for priority inversions, which is a situation in which a higher priority thread of the user mode process is waiting for (blocking on) a resource for which a lower priority thread has acquired a lock. In response to detecting such a priority inversion, the priority of the lower priority thread is boosted to allow the priority thread to execute and eventually release the lock that the higher priority thread is waiting for.