Method for processing time values in a computer or programmable machine

• US 8,185,770 B2
• Filed: 01/30/2009
• Issued: 05/22/2012
• Est. Priority Date: 01/30/2008
• Status: Active Grant

• Current Assignee: TIXEL GmbH
• Original Assignee: TIXEL GmbH
• Inventors: Siemens, Eduard, Glaeser, Frank, Brocke, Jens, Kubsch, Stefan, Koehler, Ralf, Aust, Andreas Matthias
• Primary Examiner(s): Huynh, Kim
• Assistant Examiner(s): Choudhury, Zahid
• Application Number:
  US12/322,307
• Publication Number:
  US 20090193282A1
• Time in Patent Office: 1,208 Days
• Field of Search: 713/500, 368/46, 368/47
• 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. A method for processing time values in a computer or programmable machine, comprising:

defining, in a processor, a high precision timer data comprising at least a digital number and a Boolean flag for each time value, the Boolean 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 timer; and

computing, in the processor, of two time values from the high precision timer data structure, the computing comprising an addition or subtraction operation of the digital numbers and a logical operation of the Boolean flags;

wherein;

on a condition that the two time values are added, the time values are added and the Boolean flags are combined in a logical OR operation to determine a flag value for the resulting value, or

on a condition that the two time values are subtracted, the time values are subtracted and the Boolean flags are combined in a logical XOR operation to determine the flag value for the resulting value;

and wherein the global timer flag is dominant and the local timer flag is recessive.

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

3. The 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.

4. The method according to claim 3, wherein the integer value is a 64-bit integer.

5. An apparatus having a CPU, adapted to perform a method according to claim 1.

6. A computer program product embodied in a CPU, adapted to perform a method according to claim 1, when run in a computer or programmable machine.