QSPI NOR Flash Part 2 – Memory Organization

In this article we’ll leave the package attributes behind to focus on the internal features of QSPI devices, starting with the memory organization. This article will cover the overall capacity, multi-stack devices as well as the memory map organization units such as pages, blocks and sectors.

QSPI NOR Flash Part 1 – Hardware Characteristics

In this first article, we’ll go over some important considerations to keep in mind when using a NOR for code shadowing or execute in place, and explain how these considerations may change when using the NOR for data storage with a file system. Then we’ll take a quick look at the hardware characteristics of QSPI NOR devices.

NOR vs NAND: So You Think You Know the Music?

In-depth comparison between NOR and NAND covering aspects of NOR and NAND flash technologies that, in our view, are too often ignored including the impact of the application requirements on the choice of Flash technology.

Managed vs Unmanaged: The Many Roads to Flash Storage

Road leading to an SD Card shaped sunrise.

Let’s explore and compare two different paradigms of flash management commonly used throughout the industry: managed flash and unmanaged flash. Managed flash devices include SD cards, USB flash drives, eMMC and UFS modules — also SSDs, but those are less often seen in embedded systems. These are all NAND-based devices.

Taming the Flash Beast

This article is the first of an introduction series about flash memory with a focus on embedded systems designs using an embedded file system. A high-level introduction shall we say. Not the kind that takes you straight to the electron and drags you through the depths of quantum physics. No. The purpose of this series … Read more

GCC Toolchain Eclipse Setup Guide Part 4 — Debug Configuration

Screenshot of the Eclipse CDT debug configuration panel.

In this article we’ll look at the last step of setting up a C/C++ embedded development project within Eclipse CDT. Which is creating and launching a debug configuration for the project. The kind of project managed or Makefile base does not affect the debugging process so these instructions applies to both types of projects.

Fail-Safe Storage with the TREEspan File System Part 3: Enforcing Coherence Through Transactions

Timing diagram of various high-level failures that could break the coherence of a data logging application.

In this article, we show that TSFS transactions go beyond preserving file-level integrity, and can also be used to enforce coherence across multiple files and directories. To support the discussion, we present a real-life application example and demonstrate how a single additional call to tsfs_commit() is all that is needed to make the code immune to unexpected failures.

Fail-Safe Storage with the TREEspan File System Part 2: TSFS Transactions

Time diagram of the protection afforded by a transactional file system against various unexpected failure points during a file update.

In this second article in this series we see how an application can be designed to withstand such unforeseen events, using TSFS transactions. Doing so, we introduce the tsfs_commit() API. We also discuss the write transaction atomicity property, by which applications can be safely designed ignoring potential partial update issues.

Fail-Safe Storage with the TREEspan File System Part 1: Introduction

Time diagram of various file system unexpected failures and their impact on data and metadata corruption.

This is the first article of a three-part series on fail-safe, storage-related application design using an embedded file system. The first part of the series lays out the fundamental problem of unexpected failures and briefly discusses partial solutions. The second part introduces how a fail-safe transactional file system such as the TREEspan File System (TSFS) … Read more