# US 8,543,860 B2 · Multi-core clocking system with interlocked ‘anti-freeze’ mechanism > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,860 B2 - Document ID: US8543860B2 - Status: Granted - Kind: B2 - Application number: 13/059,246 - Filed: 2008-08-26 - Published: 2011-06-16 - Granted: 2013-09-24 - Earliest claimed: 2008-08-26 - Assignees: Freescale Semiconductor, Inc. - Applicants: Derek Beattie; Carl Culshaw; Alan Devine; James Andrew Collier Scobie - Inventors: Derek Beattie; Carl Culshaw; Alan Devine; James Andrew Collier Scobie - Web page: https://patentgrep.com/patent/US8543860B2 ## CPC - G06F 1/04: Generating or distributing clock signals or signals derived directly therefrom - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A clocking system, comprises 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 the clock signals to the plurality of data processing devices, allowing to clock at least one of the data processing devices while freezing all but the at least one of the data processing devices. A method for clocking a plurality of clocked data processing devices comprises controlling a generation of a plurality of clock signals and controlling an application of the clock signals to the plurality of data processing devices, allowing to clock at least one of the data processing devices while freezing all but the at least one of the data processing devices. ## Claims ### Claim 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. ### Claim 2 (depends on 1) The clocking system as claimed in claim 1, wherein said plurality of data processing devices comprises a processor core of a multi-core device. ### Claim 3 (depends on 1) The clocking system as claimed in claim 1, wherein said plurality of data processing devices comprises a processor core of a single-core device. ### Claim 4 (depends on 1) 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. ### Claim 5 (depends on 1) The clocking system as claimed in claim 1, comprising a device for detecting a disturbance event of one of said clock signals. ### Claim 6 (depends on 1) 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. ### Claim 7 (depends on 1) 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. ### Claim 8 (depends on 7) 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. ### Claim 9 (depends on 7) 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. ### Claim 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. ### Claim 11 (depends on 10) 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. ### Claim 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. ### Claim 13 (depends on 12) 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. ### Claim 14 (depends on 12) 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. ### Claim 15 (depends on 12) 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. ### Claim 16 (depends on 12) 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. ### Claim 17 (depends on 12) The clocking system of claim 12, wherein the clock control circuit is further operable to prevent a failure by resetting the clocking system. ### Claim 18 (depends on 12) The clocking system of claim 12, wherein the first processor operates as a master device to adjust the duty cycle. ### Claim 19 (depends on 18) 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. ### Claim 20 (depends on 18) 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.