Clock Retiming Circuit for PVT Delay Mismatch Validation
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Solution Overview
Problem
In integrated circuit designs, high clock routing delays between IP blocks and data paths can occur, leading to mismatches due to process, voltage, and temperature variations, which existing technologies struggle to effectively address.
Innovation Solution
A retiming circuit and validation circuit system that introduces a delay value in a clock signal to align with data path delays, using a calibration mode to identify minimum and maximum delay values and select an intermediate value for operational mode, ensuring data integrity across varying conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If clock routing is extended to connect IP blocks and data paths, then data communication capability is improved, but clock delay increases beyond acceptable limits
Solution Approach 1:
The retiming circuit performs preliminary delay adjustment on the clock signal before it reaches the data path. By anticipating and compensating for routing delays in advance, the system ensures that clock edges arrive at the correct timing without waiting for the full routing delay to manifest, thus maintaining data communication capability while minimizing effective delay impact.
Solution Approach 2:
The system dynamically adjusts the delay value in the retiming circuit based on detected mismatches between clock and data paths. The delay parameter is not fixed but can be modified in response to changing conditions, allowing the system to adapt to varying routing delays while maintaining synchronization between clock and data signals.
2Device complexity
If fixed clock routing is used, then routing simplicity is improved, but delay mismatch due to process, voltage, and temperature variations worsens
Solution Approach 1:
The validation circuit provides feedback by comparing data samples captured with different clock timings. When a mismatch is detected, this feedback triggers adjustment of the retiming circuit's delay parameter, creating a closed-loop system that automatically compensates for PVT variations while maintaining relatively simple routing structure.
Solution Approach 2:
The system changes the delay parameter of the retiming circuit in response to detected mismatches. By dynamically adjusting this timing parameter, the system compensates for process, voltage, and temperature variations without requiring complex physical routing changes, thus maintaining routing simplicity while improving delay matching accuracy.
3Measurement precision
If delay compensation circuitry is added, then delay matching accuracy is improved, but circuit complexity increases
Solution Approach 1:
The retiming circuit acts as an intermediary between the clock source and the data path. It introduces a controllable delay that mediates the timing relationship between clock and data signals, allowing for precise delay matching without requiring complex modifications to either the clock distribution network or the data path itself.
Solution Approach 2:
The timing adjustment function is segmented into a separate retiming circuit module rather than being distributed throughout the entire system. This modular approach concentrates the complexity in a manageable, localized component while keeping the rest of the system relatively simple, thus improving delay matching accuracy without excessively increasing overall circuit complexity.
Data Source
AI summary
A device and method is provided with a first portion of the device in communication via a data line with a second portion of the device, an retiming circuit to receive a first clock from the first portion of the device and a second clock from the second portion of the device; and introduce a delay value in the second clock to generate a delayed clock; and a validation circuit to receive a data value arriving at the first portion of the device; capture a first sample of the data value sampled with the first clock; capture a second sample of the data value sampled with the delayed clock; and compare the first sample with the second sample.