Controller Memory Buffer Remapping for DRAM-Cached Reads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing data storage devices face inefficiencies in controller memory buffer (CMB) utilization due to the need for copying data from dynamic random access memory (DRAM) to CMB, which consumes additional memory and increases workload on DRAM.
Innovation Solution
Implementing a dynamic remapping mechanism that uses a LBA to DRAM module to track pre-fetched data in DRAM, allowing the host device to access data directly from DRAM without copying it to CMB, thereby optimizing CMB utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the data storage device pre-fetches data and stores it in DRAM, then read efficiency is improved, but CMB utilization is reduced due to the need to copy data to CMB
Solution Approach 1:
The patent merges the pre-fetch buffer and CMB into a single unified DRAM space, eliminating the need for separate data copies. The controller manages both functions within the same memory region, allowing pre-fetched data to be directly accessible for CMB operations without duplication.
Solution Approach 2:
The patent makes the DRAM serve multiple functions simultaneously - it acts as both the pre-fetch buffer for anticipatory data loading and the CMB for host-accessible data storage. This multi-functionality eliminates the need for separate memory regions and copying operations.
2Ease of operation
If the data storage device copies pre-fetched data from DRAM to CMB, then data is made accessible to the host, but additional memory workload and latency are introduced
Solution Approach 1:
The controller performs preliminary actions by pre-fetching data into the unified DRAM space before the host requests it. The data is already in the accessible DRAM region when needed, eliminating the need for subsequent copying operations and reducing latency.
Solution Approach 2:
By merging the pre-fetch buffer and CMB into the same DRAM space, the patent eliminates the data copying step entirely. The host can directly access pre-fetched data from the unified DRAM region without additional copy operations, reducing both time and memory workload.
Data Source
AI summary
A controller memory buffer (CMB) is used by a host device for numerous purposes. One such purpose is to have data placed in CMB in response to a read command. The data is read from the memory device and placed in the CMB. However, for efficiency purposes, the data storage device may pre-fetch data. Pre-fetched data is stored in volatile memory that is distinct from CMB, but oftentimes in dynamic random access memory (DRAM), of which the CMB is a part. Rather than copying the data from DRAM and restoring the data in CMB, the data storage device can simply provide the DRAM address without moving the data to CMB, thus saving the step of copying data from DRAM to CMB.