3D Processor Clock Grid With Resonant Child Nodes for Skew and Jitter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As processor die sizes increase, clock circuits face challenges such as insufficient drive capability, increased stage quantity, delay, and power consumption, leading to serious issues of clock skew and jitter, which hinder the ability to increase clock frequency and meet growing performance requirements.
Innovation Solution
A processor clock system is introduced, featuring a phase lock loop (PLL), a clock tree, and a clock grid with child node circuits that include a resonant and decoupling unit and a clock gating unit. These child node circuits generate multiple oscillation frequencies, absorb peak currents, and reduce power consumption, thereby improving clock performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the die scale increases to integrate more transistors, then the processor performance capability improves, but the clock circuit drive capability becomes insufficient and clock skew increases
Solution Approach 1:
The clock circuit is divided into a clock tree and a clock grid, with the clock tree responsible for long-distance signal transmission and the clock grid responsible for local signal distribution. This segmentation allows each part to be optimized independently, enabling the clock tree to provide strong drive capability for large die scales while the clock grid ensures reliable local distribution.
Solution Approach 2:
The clock grid acts as an intermediary between the clock tree and the functional units. It receives clock signals from the clock tree and distributes them locally, bridging the gap between the main clock source and various functional units across the large die, thereby maintaining drive capability and reducing clock skew.
2Productivity
If the die scale increases, then the processor integration improves, but the clock circuit stage quantity increases and delay increases
Solution Approach 1:
By segmenting the clock distribution into tree and grid structures, the signal transmission path is optimized. The clock tree uses hierarchical branching for efficient long-distance transmission, while the clock grid provides direct local connections, reducing the number of stages and overall delay compared to a single monolithic clock network.
Solution Approach 2:
The clock grid introduces a two-dimensional mesh structure for local clock distribution, replacing traditional one-dimensional bus structures. This dimensional change provides multiple parallel paths for clock signals, reducing congestion and delay in high-integration processors.
3Productivity
If the die scale increases, then the processor capability improves, but the clock circuit power consumption increases
Solution Approach 1:
The clock grid enables local clock signal distribution, allowing different regions of the processor to have independently optimized clock networks. Functional units can receive clock signals from the nearest grid node, reducing transmission distance and associated power consumption compared to a centralized clock distribution approach.
Solution Approach 2:
Dividing the clock circuit into separate tree and grid portions allows power management optimization. The clock tree can be designed for efficient long-distance transmission with lower power consumption, while the local clock grid provides short-distance distribution, collectively reducing total power consumption in large-scale processors.
4Productivity
If the die scale increases, then the processor performance improves, but the clock skew and jitter become increasingly serious
Solution Approach 1:
The segmented architecture isolates clock signal disturbances to local grid regions, preventing them from propagating across the entire die. The clock tree provides stable reference signals to multiple grid regions independently, reducing overall clock skew and jitter in high-performance processors.
Solution Approach 2:
The clock grid serves as an intermediary that buffers and stabilizes clock signals before distributing them to functional units. This intermediate stage can compensate for signal variations and reduce jitter, maintaining clock signal stability in large-scale processors where direct distribution would be problematic.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed solution enhances the performance of the clock circuit by addressing issues of clock skew and jitter, enabling higher clock frequencies and improved power efficiency, thus meeting the increasing demands of processor performance.
Implementation Method 1
The child node circuit may further support a resonant circuit that generates an oscillation frequency, to absorb a peak current in a clock circuit and reduce power consumption
Data Source
AI summary
A clock circuit constructed in a processor integrated circuit includes a phase lock loop PLL, a clock tree, and a clock grid. The clock tree includes a plurality of clock buffers in a layered structure, The clock tree is configured to receive a first clock signal clk_1 that is output by the phase lock loop PLL, and to output a second clock signal clk_2. A plurality of child node circuits (400) are disposed on some nodes of the clock grid, and are configured to generate a third clock signal clk_3 based on the second clock signal clk_2. The clock grid (330) and the clock tree (320) are distributed on multiple dies in a three-dimensional structure of the processor integrated circuit.