ODT Edge Shifting for DQS-Offset Read Timing Control
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Solution Overview
Problem
Existing semiconductor devices face challenges in dynamically managing on-die terminations (ODT) to prevent interference during read operations while enhancing write operations, requiring flexible timing control to avoid conflicts at data pins and strobe pins.
Innovation Solution
The implementation of a delay chain to shift and stretch ODT pulses, allowing independent control of rising and falling edges for data pin (DQ) and data strobe pin (DQS) signals, with DQS offset compensation to ensure proper data capture during read operations, enabling flexible timing adjustments based on read preamble lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ODT is activated to enhance write operations, then write performance is improved, but read operations may be interfered with causing conflicts at data pins
Solution Approach 1:
The patent implements dynamic control of ODT activation/deactivation based on operation type. The system selectively activates ODT during write operations to enhance write performance while deactivating ODT during read operations to prevent interference and conflicts at data pins, thus resolving the contradiction between write performance improvement and read operation reliability
Solution Approach 2:
The patent changes the termination state parameter (ODT enabled/disabled) based on the operation mode. By transitioning ODT from enabled to disabled state during read operations and vice versa during write operations, the system optimizes performance for each operation type while avoiding harmful interference, resolving the contradiction between enhanced write operations and reliable read operations
2Reliability
If RTT signal is de-asserted to create dynamic non-ODT window, then read operation conflicts are prevented, but timing control becomes rigid
Solution Approach 1:
The patent implements dynamic timing adjustment by allowing independent control of rising and falling edges of ODT pulses. The delay chain enables flexible positioning of non-ODT windows relative to read commands, making the timing control adaptive rather than rigid. This resolves the contradiction by maintaining read operation reliability through proper ODT deactivation while providing versatility in timing configuration
Solution Approach 2:
The patent segments the ODT control into independent rising edge and falling edge adjustments. By controlling each edge separately through independent delay settings, the system creates flexible non-ODT windows that can be precisely positioned to prevent read conflicts while adapting to different timing requirements, thus resolving the contradiction between reliability and adaptability
3Adaptability or versatility
If delay chain is used to shift and stretch ODT pulses, then timing flexibility is improved, but device complexity increases
Solution Approach 1:
The patent introduces a delay chain as an intermediary mechanism between the ODT control logic and the actual termination switches. This delay chain provides the necessary timing flexibility and pulse stretching functionality while isolating the complexity from the main control logic. The delay chain acts as a buffer that handles the complex timing adjustments without requiring complex control circuitry elsewhere in the system, thus resolving the contradiction between timing flexibility and device complexity
Data Source
AI summary
Devices, systems, and methods include controls for on-die termination (ODT) and data strobe signals. For example, a command to de-assert ODT for a data pin (DQ) during the read operation. An input, such as a mode register, receives an indication of a shift mode register value that corresponds to a number of shifts of a rising edge of the command in a backward or a falling edge in a forward direction. A delay chain delays the appropriate edge of received command the number of shifts in the corresponding direction to generate a shifted edge command signal. Combination circuitry then combines a falling edge command signal with a shifted rising edge command signal to form a transformed command.