GPIO Voltage-Domain Control With Fewer Level Shifters

Solution Overview

Problem

Existing integrated circuits face challenges in efficiently transferring signals across different voltage domains, particularly due to the large size and high power consumption of voltage level shifters, which can also impact reliability.

Innovation Solution

The proposed solution involves an integrated circuit (IC) design that includes a configurable I/O interface, first-domain circuitry, and second-domain circuitry, allowing for the efficient transfer of bit values and multi-bit identifiers across voltage domains using a reduced number of voltage level shifters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If voltage level shifters are used to transfer signals across different voltage domains, then signal propagation between voltage domains is enabled, but the IC size and power consumption increase

Engineering Contradiction:

Improvesignal propagation reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The I/O interface is designed to operate across multiple voltage domains (first voltage domain and second voltage domain) using a single configurable interface. By programming control bits, the same I/O interface can be configured to work with different voltage domains, eliminating the need for separate level shifter circuits for each voltage domain transition.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention changes the operational parameters of the I/O interface by programming control bits that configure the interface to operate at different voltage levels. The second-domain circuitry generates bit values for control bits that enable the interface to adapt its voltage operating parameters dynamically, allowing signal propagation across voltage domains without dedicated level shifters.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If voltage level shifters are used to transfer signals across different voltage domains, then signal propagation between voltage domains is enabled, but the IC size increases

Engineering Contradiction:

Improvesignal propagation reliabilityVSAvoidIC size

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The I/O interface is designed to operate across multiple voltage domains (first voltage domain and second voltage domain) using a single configurable interface. By programming control bits, the same I/O interface can be configured to work with different voltage domains, eliminating the need for separate level shifter circuits for each voltage domain transition.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention merges the voltage domain adaptation functionality into the I/O interface itself through configurable control bits. Instead of having separate level shifter circuits combined with the I/O interface, the voltage domain adaptation is integrated into the interface configuration, reducing the total number of circuits and IC size.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If multiple voltage level shifters are used to transfer multiple control bits, then all control bits can be configured, but the number of level shifters increases power consumption and complexity

Engineering Contradiction:

ImproveI/O interface configurabilityVSAvoidnumber of level shifters

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The I/O interface is designed to operate across multiple voltage domains (first voltage domain and second voltage domain) using a single configurable interface. By programming control bits, the same I/O interface can be configured to work with different voltage domains, eliminating the need for separate level shifter circuits for each voltage domain transition.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The second-domain circuitry generates the bit values for control bits in advance, before the actual I/O interface configuration is needed. This preliminary generation of control bit values allows the first-domain circuitry to directly program the I/O interface without requiring additional level shifters during the configuration process.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20250070783A1Voltage Domain GPIO Control

Publication Date: 2025.02.27 APPLE INC

AI summary

An integrated circuit (IC) includes an Input/Output (I/O) interface, first-domain circuitry and second-domain circuitry. The I/O interface is coupled to a first voltage domain and is configurable by a set of control bits. The second-domain circuitry is coupled to a second voltage domain and is configured to generate a bit value for a control bit among the control bits, to generate a multi-bit identifier (ID) of the control bit, and to transmit the bit value and the multi-bit ID. The first-domain circuitry is coupled to the first voltage domain and is configured to receive the bit value and the multi-bit ID, to identify the control bit from the multi-bit ID, and to configure the control bit of the I/O interface with the bit value.