SiWx917 Flash Memory Guide#

About This Guide#

This guide introduces flash memory support on the SiWx917 platform and explains how to connect, configure, and use flash devices in your application. It focuses on hardware connectivity, boot-time configuration, and best practices for reliable flash operation using the WiSeConnect™ Software Development Kit (SDK).

Use this guide when designing systems that store firmware, configuration data, or non-volatile application data in flash memory.

Whether you are building a new product or integrating flash memory into an existing design, this guide walks you through:

• How to connect flash memory to the SiWx917

• How to configure flash during system boot

• Best practices for reliable flash operation

Supported Device Variants#

The SiWx917 is available in different variants. Flash memory support depends on the selected variant.

Note: If you are using an SoC variant, you can use either external flash connected on the printed circuit board (PCB) or stacked flash integrated in the package.

Who Should Use This Guide#

This guide is designed for:

• Embedded software developers building applications on SiWx917

• Hardware designers connecting flash memory to the SiWx917

• System engineers integrating flash into their product designs

Prerequisites: Basic knowledge of embedded systems is helpful. Familiarity with the WiSeConnect SDK is beneficial but not required.

What You Will Learn#

By following this guide, you will be able to:

• Choose the right flash configuration for your application (stacked or external)

• Connect flash memory to the SiWx917 using the correct GPIO pins

• Understand how flash works on the SiWx917 platform

• Configure flash properly so your system boots correctly

• Avoid common pitfalls that can cause flash-related issues

What Is Covered in This Guide#

This guide provides comprehensive information about:

• Flash memory architecture and how it works with the SiWx917

• Hardware connectivity and which GPIO pins to use for flash connections

• Flash configuration and setup for your application

• Best practices for reliable and efficient flash operation

Flash Connectivity Overview#

You can connect one external flash device to a SiWx917 integrated circuit (IC) that has no in-package flash. The ordering part numbers (OPNs) that support an external flash connection are SiWG917M100XNTBA, SiWG917M111XGTBA, SiWG917M121XGTBA, and SiWG917M141XGTBA.

Flash connectivity is enabled through two dedicated pinsets, each supporting specific configurations. The choice of pinset depends on whether the flash is stacked or external.

The SiWx917 supports the following flash configurations:

1. Stacked flash, which is integrated inside the SiWx917 package

2. External flash, which is connected externally on the PCB

Important: You can use one flash device per SiWx917. If your SiWx917 does not have stacked flash built-in, you must connect an external flash device.

The SiWx917 provides dedicated general-purpose input/output (GPIO) pin groups for flash connectivity. The pin group you use depends on whether you are using stacked or external flash.

Flash Pin Configurations#

The SiWx917 provides two pin configurations for flash memory:

Stacked Flash (Pinset 0)#

Stacked flash is flash memory that comes pre-installed inside the SiWx917 package:

• No PCB routing required — The flash is already connected internally

• Always uses GPIO 0–5 — These pins are dedicated to the stacked flash

• Simpler design — No need to design external flash connections

Best suited for applications where you want a simpler PCB design.

External Flash (Pinset 2)#

External flash is flash memory that you connect on the printed circuit board:

• Requires PCB routing — You must route the flash signals on your board

• Uses GPIO 46–51 — These pins are dedicated to external flash

• More design flexibility — You can choose your own flash device

Best suited for applications where you need specific flash characteristics or want to reduce package cost.

Best Practices#

Follow these recommendations for successful flash integration:

• Plan early — Decide whether to use stacked or external flash during your initial design phase.

• Match configurations — Ensure your hardware pin configuration matches your boot configuration settings.

• Use SDK APIs — Use the WiSeConnect SDK flash APIs for reading, writing, and erasing flash memory. Never access flash memory directly.

• Test thoroughly — Validate your flash configuration during initial bring-up and before going to production.

• Document your setup — Keep a record of your flash type, pin configuration, and settings for future reference.

What You Need to Get Started#

Before you begin, make sure you have the following:

Tip: If you are getting started, the SiWx917 evaluation kit includes everything required to begin working with flash memory.