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US 7,804,371 B2Granted
Systems, modules, chips, circuits and methods with delay trim value updates on power-up
AssigneeSanDisk Corporation
InventorsStan Chapski, Darmin Jin, Brian Cheung
Life of this patent
Estimating the term…
Abstract
Timing measurement is performed by a digital oscillator, using a calibration value which is calculated after chip fabrication is completed, and automatically loaded into selection logic at powerup.
Claims48
A method for time measurement within an integrated circuit, comprising the actions of:
- (a) after fabrication of the integrated circuit is complete, measuring the speed of a free-running oscillator;
- (b) based on said action (a), storing a calibration value in nonvolatile NAND flash memory;
- and thereafter
- (c) when said oscillator is powered up, retrieving said calibration value and accordingly changing the number of cycles of said oscillator per interval measured.
1 more element
A method for providing a time measurement within an integrated circuit, comprising the actions of:
- powering up a free-running oscillator for at least some measurements;
- retrieving a calibration value from nonvolatile NAND flash memory, and accordingly switching gates to change a timing output which is based on said oscillator.
A method for operating a portable memory module, comprising the actions of:
- when interface timing measurement is required, powering up a free-running digital oscillator;
- retrieving a calibration value from nonvolatile memory which is integrated with said oscillator, and accordingly switching gates to change the output timing of said oscillator;
- and
- then measuring an interface timing relationship using the output timing of said oscillator.
1 more element
An integrated circuit, comprising:
- a digital oscillator;
- a nonvolatile NAND flash memory which holds a calibration value indicative of the process variation component of the speed of said oscillator;
- and
- selection logic which selects the number of cycles of said oscillator per interval measured, in dependence on said stored calibration value.
1 more element
An integrated circuit, comprising:
- a free-running digital oscillator;
- a nonvolatile memory which holds a calibration value indicative of the process variation component of the speed of said oscillator;
- and
- selection logic which selects the number of cycles of said oscillator per interval measured, in dependence on said stored calibration value;
- and
- a timing measurement stage, which outputs indications of interface timing windows in accordance with an output of said oscillator as modified by said selection logic.
3 more elements
An integrated circuit, comprising:
- a free-running digital oscillator;
- a nonvolatile memory which holds a calibration value indicative of the process variation component of the speed of said oscillator;
- and
- selection logic, integrated with said oscillator, which selects the number of cycles of said oscillator per interval measured, in dependence on said stored calibration value as loaded at power-up;
- and
- a timing measurement stage, which outputs indications of interface timing windows in accordance with an output of said oscillator as modified by said selection logic.
3 more elements
A circuit comprising:
- means for, at startup, loading a calibration value, obtained at least partly from nonvolatile NAND flash memory, into a divider circuit;
- and
- means for dividing down the output of a digital oscillator by said calibration value, to thereby produce a partially calibrated resultant timing signal.
Dependencies are inferred from the claim text.