Pseudo-Static Random Access Memory (PSRAM) API Reference#

The pseudo-static random access memory (PSRAM) application programming interfaces (APIs) in the WiSeConnect software development kit (SDK) provide a unified interface for configuring and using external PSRAM on SiWx917 devices.

Public APIs#

The PSRAM APIs include functions to:

  • Initialize the PSRAM subsystem

  • Read from and write to PSRAM data buffers

  • Optimize data transfers using direct memory access (DMA)

  • Manage PSRAM behavior across power states

These APIs provide a consistent framework for memory management across the high-performance (HP) and ultra-low-power (ULP) domains.

For a full list of function definitions, data structures, macros, and return codes, see the
đŸ‘‰ Si917 PSRAM API Reference Guide.

API Categories#

The PSRAM driver exposes the following main API categories:

  • Initialization APIs that bring the PSRAM subsystem online

  • Read and write APIs that move data between PSRAM and internal memory

  • Power-state handling APIs that reinitialize PSRAM or verify its status during power transitions

Usage Recommendations#

  1. Always initialize PSRAM using the provided SDK functions before performing any read or write operations.

  2. Use direct memory access (DMA)–assisted transfers for large data blocks to improve throughput and reduce central processing unit (CPU) load.

  3. Validate power transitions, such as sleep or standby, to ensure correct PSRAM data retention.

  4. Avoid simultaneous flash memory and PSRAM transactions to prevent bus contention.

  5. Check return codes from each API call to confirm successful operation.