System and method of determining ring oscillator speed
AssigneeUnisys Corporation
InventorsGregory K. Deal, David S. Milowicki, Chris E. Limson
Life of this patent
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Abstract
A system of determining oscillation frequency of a ring oscillator formed on a chip. The system includes a ring oscillator formed on the chip for providing a ring clock signal having first periodic pulses, and a ring counter formed on the chip for providing a ring clock count value in response to the first periodic pulses. The system also includes a terminal for receiving a system clock signal having second periodic pulses, and a system counter formed on the chip for providing a system clock count value in response to the second periodic pulses. The oscillation frequency of the ring oscillator is determined based on the ring clock count value and the system clock count value.
Claims19
A system of determining oscillation frequency of a ring oscillator formed on a chip, the system comprising:
- a ring oscillator formed on the chip for providing a ring clock signal having first periodic pulses,
- a ring counter formed on the chip for providing a ring clock count value in response to the first periodic pulses,
- a terminal for receiving a system clock signal having second periodic pulses, and
- a system counter formed on the chip for providing a system clock count value in response to the second periodic pulses,
- wherein the oscillation frequency of the ring oscillator is determined based on the ring clock count value and the system clock count value.
In a chip having a ring oscillator and a terminal for receiving a system clock, a method of determining oscillation frequency of the ring oscillator comprising the steps of:
- (a) disabling the ring oscillator and the system clock;
- (b) respectively applying a ring counter to the ring oscillator and a system counter to the system clock;
- (c) enabling the system clock;
- (d) concurrently enabling the ring oscillator and the system counter in response to said enabling step (c);
- (e) counting in the ring counter pulses of the ring oscillator and counting in the system counter pulses of the system clock;
- and
- (f) determining the oscillation frequency of the ring oscillator in response to said counting step (e).
Dependencies are inferred from the claim text.