Granted Patent B2

US 8,543,860 · App. 13/059,246 · Granted Sep 24, 2013

Abstract

Claims (53)

1. A clocking system, comprising:

a plurality of clocked data processing devices; and

a clock control circuit controlling a generation of a plurality of clock signals and an application of said clock signals to said plurality of data processing devices, allowing to clock at least one of said data processing devices while freezing all but said at least one of said data processing devices, wherein said clock control circuit is configured to adjust a time division between said clock signals by a variation of a duty cycle of at least one of said plurality of said data processing devices.

2. The clocking system as claimed in claim 1 , wherein said plurality of data processing devices comprises a processor core of a multi-core device.

3. The clocking system as claimed in claim 1 , wherein said plurality of data processing devices comprises a processor core of a single-core device.

4. The clocking system as claimed in claim 1 , wherein said freezing of all but said at least one of said data processing devices prohibits a clock disturbance of said all but said at least one of said data processing devices by a clock disturbance of said at least one data processing device.

5. The clocking system as claimed in claim 1 , comprising a device for detecting a disturbance event of one of said clock signals.

6. The clocking system as claimed in claim 1 , wherein said clock control circuit is operable to prevent a failure by resetting, freezing and stopping said clocking system.

7. The clocking system as claimed in claim 1 , wherein one of said plurality of data processing devices is a master device allowed to adjust the ratio of clock cycles driven to each of said plurality of data processing devices.

8. The clocking system as claimed in claim 7 , wherein said master device is operable to enable and disable said freezing of all but said at least one of said data processing devices.

9. The clocking system as claimed in claim 7 , wherein said clock control circuit is operable to suspend said master device and select one of said plurality of data processing devices as a new master device.

10. A method for clocking a plurality of clocked data processing devices, comprising:

controlling a generation of a plurality of clock signals; and

controlling an application of said clock signals to said plurality of data processing devices, allowing to clock at least one of said data processing devices while freezing all but said at least one of said data processing devices, wherein a time division between said clock signals is adjusted by a variation of a duty cycle of at least one of said plurality of said data processing devices.

11. The method as claimed in claim 10 , comprising:

initialising and setting anti-freeze mode of operation enabled;

clocking each of said data processing devices alternately;

checking, if a master device works correctly;

if said master device does not function correctly,

shutting off said master device; and

selecting one of said plurality of data processing devices as a new master device;

if said master device functions correctly,

adjusting duty cycles of said plurality of data processing devices; and

deciding, whether said anti-freeze mode is to be disabled;

if said anti-freeze mode is disabled,

clocking each of said data processing devices simultaneously; and

checking, whether said anti-freeze mode may be enabled; and

if said anti-freeze mode is enabled,

repeating clocking each of said data processing devices alternately.

12. A clocking system, comprising:

a first processor;

a second processor;

a clock control circuit operable to:

determine a duty cycle;

provide a system clock to the first processor and to freeze the system clock to the second processor during a first portion of the duty cycle; and

provide the system clock to the second processor and to freeze the system clock to the first processor during a second portion of the duty cycle.

13. The clocking system of claim 12 , further comprising:

a third data processor;

wherein the clock control circuit is further operable to:

provide the system clock to the third processor during the first portion of the duty cycle; and

freeze the system clock to the third processor during the second portion of the duty cycle.

14. The clocking system of claim 12 , wherein:

the first processor comprises a first core of a multi-core processor; and

the second processor comprises a second core of the multi-core processor.

15. The clocking system of claim 12 , wherein:

the first processor comprises a first single-core processor; and

the second processor comprises a second single-core processor.

16. The clocking system of claim 12 , further comprising:

a watchdog device coupled to the first processor and the second processor, and operable to detect a disturbance on one or more of the first processor and the second processor.

17. The clocking system of claim 12 , wherein the clock control circuit is further operable to prevent a failure by resetting the clocking system.

18. The clocking system of claim 12 , wherein the first processor operates as a master device to adjust the duty cycle.

19. The clocking system of claim 18 , wherein the master device further operates to enable and disable the freezing of the system clock to the first processor and to the second processor.

20. The clocking system of claim 18 , wherein the clock control circuit is further operable to suspend deselect the first processor as the master device and to select the second processor as the master device.

Assignments (21)