Apparatus and methods for leakage current reduction in integrated circuits
This disclosure relates to leakage current reduction in integrated circuits (ICs). In one aspect, an IC can include a digital logic circuit and a polarization circuit. The digital logic circuit can have a plurality of inputs and can include a plurality of logic gates. The polarization circuit can receive a standby signal and a digital input signal comprising a plurality of bits. When the standby signal is deactivated, the polarization circuit can control the plurality of inputs of the digital logic circuit based on the digital input signal. However, when the standby signal is activated the polarization circuit can control the plurality of inputs of the digital logic circuit to a low power state associated with a smaller leakage current of the plurality of logic gates relative to at least one other state of the digital logic circuit.
1. An integrated circuit comprising:
a plurality of digital logic subcircuits each having a plurality of inputs and each comprising a plurality of logic gates, wherein each of the plurality of digital logic subcircuits is configured to provide a processed signal comprising at least one bit, and wherein the plurality of digital logic subcircuits comprises a first digital logic subcircuit and a second digital logic subcircuit;
a plurality of polarization circuits each configured to receive a standby signal, and wherein the plurality of polarization circuits comprises a first polarization circuit and a second polarization circuit, wherein the first polarization circuit is configured to receive a digital input signal comprising a plurality of bits and the second polarization circuit is configured to receive a portion of the at least one bit of the processed signal of a digital logic subcircuit of the plurality of digital logic subcircuits, wherein when the standby signal is deactivated, the first polarization circuit is configured to control the plurality of inputs of the first digital logic subcircuit based on the digital input signal and the at least one polarization circuit is configured to control the plurality of inputs of the second digital logic subcircuit based on the portion of the at least one bit of the processed signal of the digital logic subcircuit of the plurality of digital logic subcircuits, and wherein when the standby signal is activated the first polarization circuit is configured to control the plurality of inputs of the first digital logic subcircuit to a low power state associated with a smaller leakage current of the plurality of logic gates of the first digital logic subcircuit relative to at least one other state of the first digital logic subcircuit and the second polarization circuit is configured to control the plurality of inputs of the second digital logic subcircuit to a low power state associated with a smaller leakage current of the plurality of logic gates of the second digital logic subcircuit relative to at least one other state of the second digital logic subcircuit; and
a first plurality of state elements configured to receive the processed signal from at least one digital logic subcircuit of the plurality of digital logic subcircuits;
wherein the integrated circuit is configured such that the first plurality of state elements are inhibited from loading a value of the processed signal when the standby signal is activated.
2. The integrated circuit of claim 1 , wherein the low power state is associated with the smallest leakage current of the plurality of logic gates relative to all other states of the plurality of digital logic subcircuits.
3. The integrated circuit of claim 1 , wherein the plurality of logic gates comprises a plurality of standard cells.
4. The integrated circuit of claim 1 , wherein when the standby signal is deactivated, the first polarization circuit is configured to control the plurality of inputs of the first digital logic subcircuit and the at least one polarization circuit is configured to control the plurality of inputs of the second digital logic subcircuit by buffering the digital input signal.
5. The integrated circuit of claim 1 , wherein when the standby signal is deactivated, the first polarization circuit is configured to control the plurality of inputs of the first digital logic subcircuit and the at least one polarization circuit is configured to control the plurality of inputs of the second digital logic subcircuit by inverting the digital input signal.
6. The integrated circuit of claim 1 , further comprising a second plurality of state elements configured to generate the digital input signal.
7. The integrated circuit of claim 1 , wherein the digital logic circuit comprises a combinational logic circuit.
8. An integrated circuit comprising:
a plurality of digital logic circuits having a plurality of inputs, wherein the digital logic circuits comprise a plurality of logic gates;
a plurality of polarization circuits each configured to receive a standby signal and digital input signals comprising a plurality of bits, wherein when the standby signal is deactivated, each of the polarization circuits are configured to control the plurality of inputs of a corresponding digital logic circuit based on the digital input signals, and wherein when the standby signal is activated each of the polarization circuits are configured to control the plurality of inputs of the corresponding digital logic circuit to a low power state associated with a smaller leakage current of the plurality of logic gates relative to at least one other state of the digital logic circuit and wherein outputs of at least some of the plurality of digital logic circuits are provided as digital input signals to polarization circuits that are coupled to corresponding digital logic circuits; and
a first plurality of state elements, wherein at least some of the plurality of digital logic circuits are configured to generate a digital output signal and to provide the digital output signal to the first plurality of state elements; and
wherein the integrated circuit is configured such that the first plurality of state elements are inhibited from loading a value of the digital output signal when the standby signal is activated.
9. The integrated circuit of claim 8 , wherein the low power state is associated with the smallest leakage current of the plurality of logic gates relative to all other states of the plurality of digital logic circuits.
10. The integrated circuit of claim 8 , wherein the plurality of digital logic circuits includes an input digital logic circuit that receives signals from digital state input elements via one of the plurality of polarization circuits and an output digital logic circuit that provides output signals to the first plurality of state elements and at least one intermediate digital logic circuit that receives input digital signals from another one of the plurality of digital logic circuits via one of the plurality of polarization circuits and provides output digital signals to another one of the plurality of polarization circuits.
11. The integrated circuit of claim 8 , wherein when the standby signal is deactivated, each of the polarization circuits are configured to control the plurality of inputs of a corresponding digital logic circuit by buffering the digital input signals.
12. The integrated circuit of claim 8 , wherein when the standby signal is deactivated, each of the polarization circuits are configured to control the plurality of inputs of a corresponding digital logic circuit by inverting the digital input signals.
13. The integrated circuit of claim 8 , further comprising a second plurality of state elements configured to generate the digital input signals.
14. The integrated circuit of claim 8 , wherein the digital logic circuit comprises a combinational logic circuit.
15. An integrated circuit comprising:
a plurality of polarized subcircuit pairs each having a digital logic subcircuit and a polarization circuit, wherein the digital logic subcircuit comprises a plurality of logic gates, wherein the polarization circuit is configured to control a plurality of inputs of the digital logic subcircuit, and wherein the digital logic subcircuit is configured to provide a processed signal comprising at least one bit;
wherein the plurality of polarized subcircuit pairs are each configured to receive a standby signal and digital input signals comprising a plurality of bits, wherein when the standby signal is deactivated, each of the polarized subcircuit pairs is configured to operate based on the digital input signals, and wherein when the standby signal is activated each of the polarized subcircuit pairs is configured to operate in a low power state associated with a smaller leakage current of the plurality of polarized subcircuit pairs relative to at least one other state of the digital logic circuit and wherein outputs of at least some of the plurality of polarized subcircuit pairs are provided as digital input signals to the polarized subcircuit pairs; and
a first plurality of state elements configured to receive the processed signal from at least one polarized subcircuit pair of the plurality of polarized subcircuit pairs;
wherein the integrated circuit is configured such that the first plurality of state elements are inhibited from loading a value of the processed signal when the standby signal is activated.
16. The integrated circuit of claim 15 , wherein the low power state is associated with the smallest leakage current of the plurality of logic gates relative to all other states of the digital logic subcircuits.
17. The integrated circuit of claim 15 , wherein the plurality of subcircuit pairs includes an input subcircuit pair that receives signals from digital state input elements and an output subcircuit pair that provides output signals to the first plurality of state elements and at least one intermediate digital logic circuit that receives input digital signals from another one of the plurality of digital logic circuits via one of the plurality of polarization circuits and provides output digital signals to another one of the plurality of polarization circuits.
18. The integrated circuit of claim 15 , wherein when the standby signal is deactivated, each of the polarized subcircuit pairs is configured to operate based on the digital input signals by buffering the digital input signals.
19. The integrated circuit of claim 15 , wherein when the standby signal is deactivated, each of the polarized subcircuit pairs is configured to operate based on the digital input signals by inverting the digital input signals.
20. The integrated circuit of claim 15 , further comprising a second plurality of state elements configured to generate the digital input signals.