Low clock power data-gated flip-flop

Patent metadata

Field	Value
Publication number	US-9966953-B2
Application number	US-201615171487-A
Country	US
Kind code	B2
Filing date	Jun 2, 2016
Priority date	Jun 2, 2016
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A low clock power data-gated flip-flop is provided. The data-gated flip-flop includes an exclusive OR component including a first exclusive OR input, a second exclusive OR input, and a first exclusive OR output. The first exclusive OR input is configured to receive a data input to the data-gated flip-flop. The data-gated flip-flop includes a first latch including a first latch data input and a first latch reset input, the first exclusive OR output being coupled to the first latch data input and the first latch reset input. The data-gated flip-flop includes a second latch having a data output, the data output coupled to the second exclusive OR input.

First claim

What is claimed is:

1. A data-gated flip-flop comprising:
an exclusive OR component including a first exclusive OR input, a second exclusive OR input, and a first exclusive OR output, the first exclusive OR input configured to receive a data input to the data-gated flip-flop;
a first latch including a first latch output, a first latch data input and a first latch reset input, the first exclusive OR output being coupled to the first latch data input and the first latch reset input; and
a second latch having a data output, the data output coupled to the second exclusive OR input.

2. The data-gated flip-flop of claim 1 , further comprising an AND gate including a first AND gate input, a second AND gate input, and an AND gate output, the first latch output being coupled to the first AND gate input, the second AND gate input being coupled to a clock signal, wherein the second latch further includes a second latch data input, and a second latch clock signal input, the second latch data input being coupled to the data input signal, the AND gate output being coupled to the second latch clock signal input.

3. The data-gated flip-flop of claim 1 , wherein a combination of the exclusive OR component and the first latch are implemented using a series of logic gates to generate the first latch output (pn1) based on the data input (D), the data output (Q), and using a clock signal (clk), the series of logic gates implementing a function logically equivalent to:
pn 1(next)=(clk× pn 1+ clk )×( D ×Q+D× Q ).

4. The data-gated flip-flop of claim 3 , wherein within the series of logic gates the clock signal toggles on only four devices when the data input to the data-gated flip-flop is equal to an output signal at the data output of the second latch.

5. The data-gated flip-flop of claim 4 , wherein the clock signal drives a series of transistors at different logic levels within the series of logic gates.

6. The data-gated flip-flop of claim 3 , wherein within the series of logic gates the clock signal toggles on only five devices when the data input to the data-gated flip-flop is equal to an output signal at the data output of the second latch.

7. The data-gated flip-flop of claim 6 , wherein the clock signal drives a series of transistors at the same logic level within the series of logic gates.

8. The data-gated flip-flop of claim 1 , wherein the first latch comprises a D latch.

9. The data-gated flip-flop of claim 1 , wherein the second latch comprises a D latch.

10. A data-gated flip-flop comprising:
a clock gating circuit, the clock gating circuit generating a clock gating signal (pn1), based on a data input (D), a data output (Q), and using a clock signal (clk), the clock gating signal having a logical value logically equivalent to:
pn 1(next)=(clk× pn 1+ clk )×( D ×Q+D× Q ); and

an output latch, a clock to the output latch gated by the clock gating signal.

11. The data-gated flip-flop of claim 10 , wherein, within a series of logic gates forming the data-gated flip-flop, the clock signal toggles on only four devices when a data input to the data-gated flip-flop is equal to the data output (Q) of the data-gated flip-flop.

12. The data-gated flip-flop of claim 11 , wherein the clock signal drives a series of transistors at different logic levels within the series of logic gates.

13. The data-gated flip-flop of claim 10 , wherein, within a series of logic gates forming the data-gated flip-flop, the clock signal toggles on only five devices when the data input (D) to the data-gated flip-flop is equal to an output signal at the data output (Q) of the data-gated flip-flop.

14. The data-gated flip-flop of claim 13 , wherein the clock signal drives a series of transistors at the same logic level within the series of logic gates.

15. The data-gated flip-flop of claim 10 , wherein the clock gating circuit further comprises an input latch, the input latch comprising a D latch.

16. The data-gated flip-flop of claim 10 , wherein the output latch comprises a D latch.

17. A method of operating a data-gated flip-flop comprising:
flowing a current through an exclusive OR component including a first exclusive OR input, a second exclusive OR input, and a first exclusive OR output, the first exclusive OR input configured to receive a data input to the data-gated flip-flop;
flowing a current through a first latch including a first latch output, a first latch data input and a first latch reset input, the first exclusive OR output being coupled to the first latch data input and the first latch reset input; and
flowing a current through a second latch having a data output, the data output coupled to the second exclusive OR input.

18. The method of claim 17 , further comprising flowing a current through an AND gate including a first AND gate input, a second AND gate input, and an AND gate output, the first latch output being coupled to the first AND gate input, the second AND gate input being coupled to a clock signal, wherein the second latch further includes a second latch data input, and a second latch clock signal input, the second latch data input being coupled to the data input signal, the AND gate output being coupled to the second latch clock signal input.

19. The method of claim 17 , wherein a combination of the exclusive OR component and the first latch are implemented using a series of logic gates to generate the first latch output (pn1) based on the data input (D), the data output (Q), and using a clock signal (clk), the series of logic gates implementing a function logically equivalent to:
pn 1(next)=(clk× pn 1+ clk )×( D ×Q+D× Q ).

20. The method of claim 17 , further comprising toggling a clock signal on only four devices within a series of logic gates forming the data-gated flip-flop when the data input to the data-gated flip-flop is equal to an output signal at the data output of the second latch.

21. The method of claim 20 , further comprising driving the clock signal on a series of transistors at different logic levels within the data-gated flip-flop.

22. The method of claim 17 , further comprising toggling a clock signal on only five devices within a series of logic gates forming the data-gated flip-flop when the data input to the data-gated flip-flop is equal to an output signal at the data output of the second latch.

23. The method of claim 22 , further comprising driving the clock signal on a series of transistors at the same logic level within the data-gated flip-flop.

24. A data-gated flip-flop comprising:
means for flowing a current through an exclusive OR component including a first exclusive OR input, a second exclusive OR input, and a first exclusive OR output, the first exclusive OR input configured to receive a data input to the data-gated flip-flop;
means for flowing a current through a first latch including a first latch output, a first latch data input and a first latch reset input, the first exclusive OR output being coupled to the first latch data input and the first latch reset input; and
means for flowing a current through a second latch having a data output, the data output coupled to the second exclusive OR input.

25. The data-gated flip-flop of claim 24 , further comprising means for flowing a current through an AND gate including a first AND gate input, a second AND gate input, and an AND gate output, the first latch output being coupled to the first AND gate input, the second A

Assignees

• Qualcomm Inc

Inventors

• Ye Qi
• Datta Animesh
• Pang Bo

Classifications

• H03K3/0372

  of the primary-secondary type · CPC title

• H03K3/037

  Bistable circuits · CPC title

• H03K19/21

  EXCLUSIVE-OR circuits, i.e. giving output if input signal exists at only one input; COINCIDENCE circuits, i.e. giving output only if all input signals are identical · CPC title

• H03K3/012

  Modifications of generator to improve response time or to decrease power consumption · CPC title

• H03K19/0016 Primary

  by using a control or a clock signal, e.g. in order to apply power supply · CPC title