This repository demonstrates how to interface the AP Memory APS6404L (8MB PSRAM) with an STM32G474 using Quad-SPI (QSPI) with DMA, achieving high-speed memory transfers. The STM32G474 has only 128 KB of internal RAM, but this external PSRAM significantly expands memory capacity, making it suitable for applications like continuous data acquisition.
- Microcontroller: STM32G474 (128 KB SRAM)
- PSRAM: APS6404L (8 MB, Quad-SPI)
- Board: Custom PCB (signal integrity issues above 25 MHz)
- QSPI Clock: Limited to ~24.3 MHz (Prescaler 6)
- Mode: Quad-SPI (QPI) in wrap mode (32-byte bursts)
- Transfer Type: Blocking & DMA-based QSPI transfers
| Transfer Mode | Write Speed | Read Speed |
|---|---|---|
| Blocking (CPU) | 1.14 MB/s | 1.33 MB/s |
| DMA (Peripheral) | 10.00 MB/s | 10.00 MB/s |
⚡ Using DMA for both read & write boosted speeds to 10 MB/s!
⚠ Above 25 MHz, signal integrity degrades on the custom board, limiting further improvements.
- QSPI initialization, wrap mode setup (0x5F)
- Fast read/write (0xEB / 0x38)
- DMA-based QSPI transfers
- Speed tests & data integrity checks
- Minimal setup required—just connect APS6404L to STM32G4's QSPI pins!
psram_aps6404l.c/h→ QSPI driver for APS6404Lmain.c→ Initialization, speed tests, DMA callbacksREADME.md→ This file 😎
- Clone the repository:
git clone https://github.com/yourusername/STM32G4-PSRAM-DMA-QSPI.git