Adaptive clocking scheme
Adaptive clocking schemes for synchronized on-chip functional blocks are provided. The clocking schemes enable synchronous clocking which can be adapted according to changes in signal path propagation delay due temperature, process, and voltage variations, for example. In embodiments, the clocking schemes allow for the capacity utilization of a logic path to be increased.
1. A system, comprising:
a first functional block;
a first latch circuit coupled to an output of the first functional block and configured to receive a system clock;
a second functional block;
a second latch circuit coupled to an input of the second functional block and configured to receive the system clock;
a logic path that couples an output of the first latch circuit and an input of the second latch circuit;
a clock path having a first endpoint and a second endpoint, the first endpoint and the second endpoint being coupled to an input of the first latch circuit and a second input of the second latch circuit, respectively, and
a feedback path coupled between a tap point of the clock path and the first end point of the clock path,
wherein the frequency of the system clock is configured to vary according to temperature, process, and voltage variations of the propagation delay of the clock path.
2. The system of claim 1 , further comprising:
a clock module configured to generate the system clock and to provide the system clock to the first latch circuit.
3. The system of claim 2 , wherein the clock module is configured to send the system clock over the clock path to the second latch circuit.
4. The system of claim 1 , wherein the clock path and the feedback path form a ring oscillator circuit.
5. The system of claim 4 , wherein an output frequency of the ring oscillator circuit is a function of a propagation delay of the clock path.
6. The system of claim 5 , wherein the output frequency of the ring oscillator circuit is proportional to a propagation delay of a fraction of the clock path.
7. The system of claim 5 , wherein the output frequency of the ring oscillator circuit is configured to vary according to changes in supply voltage, thereby adjusting a frequency of the system clock based on supply voltage variations.
8. The system of claim 1 , wherein a frequency of the system clock is configured to be a function of a propagation delay of the clock path.
9. The system of claim 8 , wherein the propagation delay of the clock path is configured to be equal to a propagation delay of the logic path.
10. A method, comprising:
coupling an output of a first functional block to a first latch circuit;
coupling an input of a second functional block to a second latch circuit;
coupling a system clock to the first latch circuit and the second latch circuit;
coupling, using a logic path, an output of the first latch circuit and an input of the second latch circuit;
coupling a first endpoint of a clock path to an input of the first latch circuit;
coupling a second endpoint of the clock path to a second input of the second latch circuit;
coupling a feedback path between a tap point of the clock path and the first end point of the clock path; and
configuring the frequency of the system clock to vary according to temperature, process, and voltage variations of the propagation delay of the clock path.
11. The method of claim 10 , further comprising:
generating the system clock using a clock module; and
providing the system clock to the first latch circuit using the clock module.
12. The method of claim 11 , further comprising:
transmitting the system clock over the clock path to the second latch circuit.
13. The method of claim 10 , further comprising:
forming a ring oscillator based on the clock path and the feedback path.
14. The method of claim 13 , further comprising:
configuring an output frequency of the ring oscillator to be a function of a propagation delay of the clock path.
15. The method of claim 14 , further comprising:
configuring the output frequency of the ring oscillator to be proportional to a propagation delay of a fraction of the clock path.
16. The method of claim 14 , further comprising:
varying the output frequency of the ring oscillator according to changes in a supply voltage, thereby adjusting a frequency of the system clock based on variations in the supply voltage.
17. The method of claim 10 , further comprising:
configuring a frequency of the system clock to be a function of a propagation delay of the clock path.
18. The method of claim 17 , further comprising:
configuring the propagation delay of the clock path to be equal to a propagation delay of the logic path.
19. A system, comprising:
a first functional block;
a first latch circuit, coupled to an output of the first functional block and configured to receive a system clock;
a second functional block;
a second latch circuit, coupled to an input of the second functional block and configured to receive the system clock;
a logic path that couples an output of the first latch circuit and an input of the second latch circuit;
a clock path having a first endpoint and a second endpoint, the first endpoint and the second endpoint being coupled to an input of the first latch circuit and a second input of the second latch circuit, respectively, and
a feedback path coupled between a tap point of the clock path and the first end point of the clock path,
wherein the frequency of the system clock is configured to vary according to temperature, process, and voltage variations of the propagation delay of the clock path.
20. The system of claim 19 , wherein the clock path and the feedback path are configured and arranged to form an oscillator circuit, the oscillator circuit being configured to provide an output signal having an output frequency that is based on a propagation delay of the clock path.