Programmable Memory Controller Selective Chip Activation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current processor-based systems face inefficiencies in memory access due to the need to activate all memory chips for a memory access, even when only a subset of data is required, leading to wasted power and bandwidth, especially in workloads with low spatial locality.
Innovation Solution
A programmable memory controller that selectively activates specific memory chips based on a memory access policy, using dedicated chip select lines to allow for flexible data line sizing and efficient memory access by enabling burst chops and sequential access to individual memory chips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If all memory chips are activated for a memory access, then the data bandwidth is maximized, but power consumption increases and bandwidth is wasted when only a subset of data is required
Solution Approach 1:
The memory system divides the memory chips into multiple independently selectable groups or banks. Each memory chip can be individually activated or deactivated through separate chip select lines, allowing the system to segment memory access operations. This segmentation enables selective activation of only the necessary memory chips for a given access pattern, reducing power consumption and avoiding bandwidth waste while maintaining efficient access to the required data subsets.
2Loss of energy
If all memory chips are activated for a memory access, then the data transfer speed is maximized, but available bandwidth decreases when only a subset of data is needed
Solution Approach 1:
The memory controller dynamically configures the number and combination of activated memory chips based on the specific access requirements. The system can adaptively adjust which memory chips are active for each memory access operation, optimizing the balance between access speed and bandwidth utilization. This dynamic configuration allows the system to maintain high access speed for required data while minimizing unnecessary bandwidth consumption by activating only the necessary subset of memory chips.
3Adaptability or versatility
If dedicated chip select lines are provided to each memory chip, then selective access to subsets of memory chips is enabled, but device complexity increases
Solution Approach 1:
The chip select lines are designed to serve multiple functions: they can individually select specific memory chips, group chips into banks, and support various access patterns including sequential and random access. This multi-functionality allows the same set of chip select lines to handle diverse memory access requirements without requiring additional dedicated control signals for each function, thereby reducing the overall complexity increase while maintaining high adaptability.
Data Source
AI summary
A memory system supporting programmable selective access to subsets of parallel-arranged memory chips for efficient memory accesses is disclosed. A memory controller is programmable to selectively control a number of parallel-arranged memory chips in the memory system activated in a grouping for a memory access based on a memory access policy. The memory access policy is based on the number of memory chips to be activated to achieve the desired data line size for a given memory access. This programmability of the memory controller is made possible by separate dedicated chip select lines being coupled to each memory chip. Being able to only activate a subset of the memory chips for a memory access allows conservation of data bus bandwidth and power that would otherwise by consumed by asserting unused data on the data buses.