Semiconductor Die ODT Control for DRAM Stub Reflection Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
On-die termination (ODT) technologies struggle to effectively manage signal reflections and noise introduction in semiconductor systems, particularly in DRAM modules, due to impedance discontinuities at stub connections, which existing termination resistors on motherboards fail to address adequately.
Innovation Solution
A semiconductor die is configured to control on-die termination (ODT) by generating and managing ODT control signals between semiconductor dies, allowing for responsive ODT circuits to adjust impedance matching within the semiconductor chip, reducing the need for external resistors and complex wiring on the motherboard.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If termination resistors are disposed on the motherboard, then signal reflection from stub lines cannot be prevented, but the system design becomes more complex with additional external components
Solution Approach 1:
The patent merges the termination resistor function directly into the semiconductor die by integrating ODT circuits within the chip architecture. This combines the memory function and termination function into a single integrated component, eliminating the need for separate external termination resistors on the motherboard and thereby reducing system design complexity while maintaining signal reflection prevention capability
2Device complexity
If ODT circuits are integrated within the semiconductor die, then the number of external resistor elements is reduced, but power consumption increases due to continuous ODT operation
Solution Approach 1:
The patent implements dynamic control of ODT circuits by providing separate ODT control signals (first ODT control signal for reading operations, second ODT control signal for writing operations) that selectively activate ODT circuits based on the current operation mode. This dynamic activation/deactivation approach reduces power consumption compared to continuous ODT operation while maintaining impedance matching benefits during active transactions
Solution Approach 2:
The ODT circuits are activated periodically based on read/write operations rather than continuously. The control signals are generated in response to specific operation types, creating a periodic activation pattern that reduces overall power consumption while maintaining signal integrity during active data transfers
3Reliability
If ODT control signals are transmitted between semiconductor dies, then impedance matching is improved, but signal transmission time increases
Solution Approach 1:
The patent generates ODT control signals in advance based on the type of operation (read or write) before data transmission begins. The first ODT control signal is generated in response to a read command, and the second ODT control signal is generated in response to a write command, allowing ODT circuits to be pre-configured for the upcoming operation, thereby minimizing delay during actual data transfer
Data Source
AI summary
A semiconductor die includes a first pin configured to output a first on-die termination (ODT) control signal to a second semiconductor die, the second semiconductor die comprising a plurality of second ODT circuits each having an ODT that is responsive to the first ODT control signal; and a second pin configured to receive a second ODT control signal output from the second semiconductor die, the semiconductor die comprising a plurality of first ODT circuits each having an ODT that is responsive to the second ODT control signal.