Method for processing time values in a computer or programmable machine

• US 20090193282A1
• Filed: 01/30/2009
• Published: 07/30/2009
• Est. Priority Date: 01/30/2008
• Status: Active Grant

• Current Assignee: TIXEL GmbH
• Original Assignee: TIXEL GmbH
• Inventors: Siemens, Eduard, Brocke, Jens, Kubsch, Stefan, Glaeser, Frank, Koehler, Ralf, Aust, Andreas Matthias
• Granted Patent: US 8,185,770 B2
• Time in Patent Office: Days
• US Class Current: 713/500
• CPC Class Codes: G06F 1/14 Time supervision arrangements, e.g. real time clock

Abstract

Modern computers (10, 20) come with different timers having different attributes like time resolution, supported time range and time reference. Some are local timers, representing relative time values like the TSC counter (11, 21) counting CPU cycles from the power on or reset of the computer. Some are global timers, representing an absolute or real time. Having different classes of timers in the computer (10, 20), a number of computations need to be performed to tie the different timers to each other.

It is the idea of the invention to define a single high resolution timer structure wherein the time value is represented with a digital number and a flag clarifies whether the timer is a global timer or local timer. The invention enables a much faster processing of the time values. The global time, tied to a high-resolution timer can be tracked much faster. This means better precision of scheduling of time critical jobs, like packet scheduling for data transport.

Claims

1. Method for processing time values in a computer or programmable machine, characterized in that a high precision timer structure is defined consisting of at least a digital number for the time value plus a flag clarifying whether the timer is representing an absolute or real time herein after called global timer or if the timer is representing a relative time, herein after called local time.

2. Method according to claim 1, wherein the global timer representing an absolute or real time value has a meaning with a concrete date an time and wherein the local timer representing a relative time has no association to a concrete date and time.

3. Method according to claim 1, wherein on addition of two time values from the high precision timer structure, the time values will be added and the flags will be combined in a logical OR operation to get the entry in the flag for the resulting value, wherein the global timer flag is dominant and the local timer flag is recessive.

4. Method according to claim 1, wherein on subtraction of two time values from the high precision timer structure the time values will be subtracted and the flags will be combined in a logical XOR operation to get the entry in the flag for the resulting value, wherein the global timer flag is dominant and the local timer flag is recessive.

5. Method according to claim 1, wherein the digital number for the time value corresponds to an integer value that has a bit length sufficient to represent a counter value from a time stamp counter TSC of a CPU.

6. Method according to claim 5, wherein the integer value is a 64-bit integer.

7. Apparatus adapted to perform a method according to claim 1.

8. Computer program product adapted to perform a method according to claim 1, when run in a computer or programmable machine.