Die-to-Die Link Isolation Handshake for Low-Latency Power Gating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing die-to-die interfaces in computing systems face challenges with power management inefficiencies and electrical risks due to independent power gating of dies, leading to issues like excessive power leakage and electrostatic discharge latch-up, which are not adequately addressed by current isolation mechanisms.
Innovation Solution
A modular low latency electrical sequence is implemented using a 3-wire communication interface for die-to-die links, allowing independent power gating of each die with a single gated supply rail, and includes a quiescence handshake to safely transition dies into electrical idle or active states, ensuring both transmitter and receiver isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If independent power gating of dies is implemented, then power consumption is reduced, but electrical risks such as electrostatic discharge latch-up increase
Solution Approach 1:
The patent applies preliminary action by transitioning the receiver into isolation mode before the transmitter is powered down. This sequence prevents electrostatic discharge latch-up by ensuring the receiver is protected before any power changes occur on the transmitter side, thereby maintaining electrical stability while enabling independent power gating
Solution Approach 2:
The patent introduces an intermediary isolation mode that acts as a buffer between the transmitter and receiver during power transitions. This intermediate state protects the receiver from electrical risks while allowing the transmitter to be gated down, resolving the contradiction between power savings and electrical stability
2Reliability
If receiver is placed in isolation mode before transmitter power down, then electrostatic discharge latch-up is prevented, but power management complexity increases
Solution Approach 1:
The patent segments the power management process into distinct phases: receiver isolation, transmitter power down, and acknowledgment. This segmentation transforms a complex simultaneous operation into manageable sequential steps, reducing power management complexity while maintaining electrical stability
Solution Approach 2:
The patent implements feedback through an acknowledgment signal sent from the first die to the second die after the receiver is isolated. This feedback mechanism coordinates the power down sequence, simplifying the overall control logic by using simple signal exchanges rather than complex centralized control
3Loss of time
If modular electrical sequence with handshake is used, then transition latency is reduced, but communication overhead increases
Solution Approach 1:
The patent applies local quality by implementing the handshake protocol only during power transition states, not during normal operation. The isolation and deisolation sequences use targeted communication signals specifically when needed, minimizing communication overhead while achieving low transition latency during state changes
Data Source
AI summary
A system comprising a first die comprising a first receiver and a first transmitter to couple to a link between the first die and a second die comprising a second receiver and a second transmitter; and circuitry to place the first receiver and first transmitter into isolation modes; provide a first signal to the second die to request placement of the second transmitter into a deisolation mode; place the first receiver and first transmitter into deisolation modes responsive to a second signal from the second die; and provide a third signal to the second die to request placement of the second receiver into a deisolation mode.