Memory Signaling with Concurrent PAM and NRZ Paths
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Solution Overview
Problem
Current memory devices face limitations in achieving high data transfer rates, reliability, and reduced power consumption due to the constraints of existing signaling techniques, particularly in volatile memory technologies like DRAM, which require frequent refreshing and have limited data retention.
Innovation Solution
Implementing a memory controller that communicates signals using multiple modulation schemes, such as a multi-symbol scheme with at least three levels and a binary-symbol scheme with two levels, over separate signal paths to enhance read and write speeds, performance, and reliability, while reducing power consumption and manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single modulation scheme is used for data transmission in memory devices, then the device complexity is reduced, but the data transfer rate and power efficiency are limited
Solution Approach 1:
The patent segments the data transmission process by dividing data into different types (e.g., command data, data bus data, address data) and assigning different modulation schemes to different signal paths. This allows each signal path to be optimized independently for its specific data type, achieving high data transfer rates without requiring the entire system to use complex modulation schemes.
Solution Approach 2:
The patent implements dynamic selection of modulation schemes based on the type of data being transmitted. The memory controller dynamically chooses between first and second modulation schemes for different signal paths, allowing the system to adapt its complexity to the specific transmission requirements of each data type, thereby improving overall productivity without excessive complexity.
2Productivity
If the frequency of data transfer is increased to improve data transfer rate, then productivity increases, but power consumption increases significantly
Solution Approach 1:
The patent changes the modulation parameters (e.g., using different modulation schemes with different symbol rates and data rates) to achieve high data transfer rates without proportionally increasing the frequency of data transfer. By optimizing the modulation parameters for different data types, the system achieves high productivity while controlling power consumption.
3Quantity of substance
If memory cell density is increased to improve storage capacity, then the quantity of stored data increases, but signal transmission reliability deteriorates
Solution Approach 1:
The patent applies different modulation schemes to different signal paths based on their specific requirements. By optimizing the modulation scheme for each signal path's characteristics and data type, the system maintains signal transmission reliability even as memory cell density increases and signal integrity becomes more challenging.
Data Source
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AI summary
Methods, systems, and devices for multiple concurrent modulation schemes in a memory system are described. Techniques are provided herein to communicate data using a modulation scheme having at least three levels and using a modulation scheme having at least two levels within a common system or memory device. Such communication with multiple modulation schemes may be concurrent. The modulated data may be communicated to a memory die through distinct signal paths that may correspond to a particular modulation scheme. An example of a modulation scheme having at least three levels may be pulse amplitude modulation (PAM) and an example of a modulation scheme having at least two levels may be non-return-to-zero (NRZ).