Pseudo-Static Random Access Memory (PSRAM) Usage Scenarios#

On SiWx917 devices, pseudo-static random access memory (PSRAM) acts as an external high-speed memory resource that complements on-chip random access memory (RAM). It is well suited for the following use cases:

  • Large and dynamic data buffers

  • High-throughput networking

  • Graphics and UI storage

  • Real-time data processing workloads

This section describes common PSRAM use cases and recommended practices for designing SiWx917-based systems.

Scenario 1: Large Data Buffer Management#

PSRAM is well suited for managing large temporary data sets that exceed on-chip memory capacity. It enables continuous data handling without impacting processor performance or overall system throughput.

Typical applications include:

  • Audio and video streaming buffers

  • Network packet buffering

  • Image processing pipelines

  • Data processing queues for edge analytics

Benefit: PSRAM provides scalable buffer space for data-intensive operations such as multimedia processing and sensor fusion.

Scenario 2: Network Applications#

Networking stacks require high-speed memory to manage packet flow and protocol data efficiently. PSRAM adds dynamic storage capacity for communication-heavy applications.

Typical applications include:

  • Transmission control protocol and internet protocol (TCP/IP) packet buffering

  • Protocol stack memory allocation

  • Network data caching

  • Queue management for gateway devices

Benefit: PSRAM reduces latency and prevents packet loss in real-time communication environments.

Scenario 3. Graphics and Display Systems#

Display and graphics applications require substantial frame storage and fast memory refresh cycles. PSRAM supports high-performance display operations and smooth image rendering.

Typical applications include:

  • Framebuffer storage for LCD/OLED displays

  • Texture storage for 2D/3D graphics engines

  • Animation and UI rendering buffers

  • Off-screen rendering and double-buffering

Benefit: PSRAM enables high frame-rate rendering and reduces flicker or tearing during display refresh cycles.

Scenario 4: Real-Time Data Processing#

Real-time embedded applications require deterministic performance and predictable memory access behavior. PSRAM provides low-latency, high-bandwidth storage for continuous data capture and analysis.

Typical applications include:

  • Sensor data logging and buffering

  • Real-time signal processing pipelines

  • Edge AI/ML inference result caching

  • High-speed acquisition and analytics buffers

Benefit: PSRAM ensures consistent data throughput for time-sensitive systems such as industrial controllers or IoT gateways.

Best Practices#

Best Practice

Recommendation

Optimize Access Patterns

Use sequential burst read and write operations to maximize quad serial peripheral interface (QSPI) efficiency.

Leverage DMA

Enable direct memory access (DMA) transfers for large or repetitive data movements to reduce central processing unit (CPU) load.

Validate Timing

Ensure QSPI timing parameters match the PSRAM device datasheet.

Use Power Management

Transition PSRAM into low-power or self-refresh mode during idle periods.

Memory Testing

Implement startup memory validation, such as write and read tests, to improve reliability.