Memory Wake Circuit Using Dedicated WAKE Bus and ID Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional memory systems face interference issues when toggling a shared clock enable (CKE) signal to wake up memory devices, as it also controls clock signal access for other devices, leading to errors and latency.
Innovation Solution
A shared WAKE bus and device identification (ID) system is introduced to wake up low power memory devices without interrupting the CKE signal, using a low power wake circuit that receives a wake signal and identification information to initiate a transition from a low power state to an active state only when the information matches the device identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the CKE signal is toggled to wake up a memory device, then the memory device transitions from low power state to active state, but clock signal access for other memory devices is interfered with
Solution Approach 1:
The patent segments the wake-up function from the CKE signal by introducing a dedicated WAKE signal. This separates the device selection function (CKE) from the wake-up function (WAKE), allowing independent control. The CKE signal continues to manage clock signal access for active devices while the WAKE signal specifically triggers low power state exits without interfering with clock distribution.
Solution Approach 2:
The patent introduces a new WAKE signal as an intermediary dedicated to wake-up operations. This mediator signal handles the specific function of transitioning devices from low power state without involving the CKE signal, thereby eliminating the interference problem while achieving the wake-up objective.
2Device complexity
If the CKE signal is used to control both wake up and clock signal access, then the number of control signals is reduced, but operation errors and latency increase
Solution Approach 1:
The patent divides the combined control functions into separate signals: CKE for clock signal access control and WAKE for wake-up operations. This segmentation eliminates the conflicts and errors caused by multiplexing both functions in a single signal, improving operational accuracy while maintaining a manageable signal count through systematic control.
3Device complexity
If multiple memory devices share a CKE signal, then the system uses fewer control signals, but wake up operations interfere with concurrent device operations
Solution Approach 1:
The patent segments control functions by introducing a dedicated WAKE signal for wake-up operations while maintaining shared CKE signal for clock control. This allows simultaneous wake-up commands to multiple devices without interfering with their individual clock signal access, eliminating latency caused by sequential CKE toggling.
Solution Approach 2:
The WAKE signal acts as an intermediary that enables parallel wake-up operations for multiple devices without affecting their clock signal timing. Each device responds to WAKE independently while CKE continues to manage clock distribution, allowing concurrent operations without the timing conflicts and latency inherent in shared CKE-based wake-up.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
According to one embodiment, an apparatus is disclosed. The apparatus includes a memory device having a device identification, The apparatus further includes a low power wake circuit configured to receive a low power wake signal and an identification information, and further configured to initiate a transition of the memory device from a low power state to an active state responsive to an active low power wake signal and the wake identification information matching the device identifier.