Create Reset-the-flash-memory-on-STM32H747-based-devices.md (#423)

* Create Reset-the-flash-memory-on-STM32H747-based-devices.md

* Update content/Hardware Support/Generic/Reset-the-flash-memory-on-STM32H747-based-devices.md

Co-authored-by: Renat0Ribeir0 <86349945+Renat0Ribeir0@users.noreply.github.com>

* Added more info on uses of procedure

* Format PLC IDE runtime info as note

---------

Co-authored-by: Renat0Ribeir0 <86349945+Renat0Ribeir0@users.noreply.github.com>

content/Hardware Support/Generic/Reset-the-flash-memory-on-STM32H747-based-devices.md

@@ -0,0 +1,49 @@
+---
+title: "Reset the flash memory on STM32H747-based devices"
+---
+
+Learn how to reset the QSPI flash memory for STM32H747-based Arduino devices by uploading a utility sketch. The sketch will remove any previous partitioning scheme, and recreate the factory-defined partition scheme. Finally, the latest connectivity firmware and TLS certificates are reinstalled.
+
+You may want to use this procedure to:
+
+* Restore the factory-defined memory allocation for full support of Arduino IDE or Arduino Cloud.
+* Resolve issues with storage or connectivity.
+
+> [!IMPORTANT]
+> Resetting the flash memory will remove the PLC IDE runtime. [Reinstall the runtime](https://docs.arduino.cc/software/plc-ide/tutorials/plc-ide-setup-license/#3-download-the-runtime) to continue using PLC IDE with your device.
+
+Supported devices:
+
+* GIGA R1 WiFi
+* Opta
+* Portenta H7
+* Portenta Machine Control
+
+---
+
+**Follow these steps:**
+
+1. Download the following sketch:
+
+ [memory_partitioning.zip](https://docs.arduino.cc/3147be35e0c40957022af51f015c3e4d/memory_partitioning.zip){.link-download}
+
+1. Open the sketch in your editor:
+
+ * Arduino IDE: Extract the .zip into your [Sketchbook](https://support.arduino.cc/hc/en-us/articles/4412950938514-Open-the-Sketchbook-folder). Ensure both `memory_partitioning.ino` and `certificates.h` are inside a folder named `memory_partitioning`.
+
+ * Cloud Editor: Open the [Sketches tab](https://app.arduino.cc/sketches) and click on the **Create** button in the top-right corner. Select **Import local file** in the dropdown menu and import `memory_partitioning.zip`.
+
+1. Open the imported sketch in your editor.
+
+1. Connect your device to your computer and select the device in the editor.
+
+1. Click ![Upload button](img/symbol_upload2.png) **Upload** to upload the sketch to the device.
+
+1. Click the ![Serial Monitor button](img/symbol_monitor.png) **Serial Monitor** button in the top-right corner or select Tools > Serial Monitor (IDE only).
+
+1. Open the Serial Monitor. When this message appears, the process is complete:
+
+ ```
+ Firmware and certificates updated!
+ It's now safe to reboot or disconnect your board.
+ ```