When developing firmware, performance, memory footprint, and safety are critical. That is where keywords like const and constexpr come into play. At first glance, both seem to make variables immutable, but they differ significantly in when and how they achieve this. In this post, I will explain the technical depth behind const and constexpr, their
const vs constexpr in C++ Explained with Embedded Examples Read More »
In embedded systems — especially with microcontrollers like the STM32H5 (Cortex-M33) — linking is not just a toolchain step. It represents the final integration point where independently compiled code modules, memory layout constraints, and hardware-specific expectations converge into a working binary. Yet, many engineers treat the linker as a black box — something that “just
How the IAR Linker Resolves Function Calls Across Files in ARM Cortex-M Read More »
When writing low-level embedded C code for ARM Cortex-M, understanding the ARM function call stack frame is essential for analyzing memory usage, optimizing performance, and debugging hard faults. This post dives deep into the ARM calling conventions, stack frame setup, and the distinction between caller-saved and callee-saved registers — all through practical examples. ARM Cortex-M
How the ARM Function Call Stack Frame Works (With C & Assembly Examples) Read More »
When integrating a Real-Time Clock (RTC) into embedded systems, especially in ultra-low-power or time-critical applications, some issues may not become apparent until after deployment. These issues can result in unexpected behavior, data loss, or inaccurate timekeeping. Below is a comprehensive list of real-world RTC challenges commonly faced by developers and product teams, particularly when working
Common RTC Issues in Embedded Systems (STM32) and How to Solve Them Read More »
An RTC (Real-Time Clock ) is a specialized timing component used to maintain accurate timekeeping. It is essential in applications where precise, scheduled operations are required. Beyond its use in clocks and watches, RTCs play a critical role in devices like smart meters, washing machines, medicine dispensers, data loggers, and other time-sensitive systems. STM32 comes
Tips for Using RTC in STM32H5 Microcontrollers Read More »
In embedded systems, sharing clock signals externally is often essential for synchronizing peripherals or other microcontrollers. Most of the popular Microcontrollers often need to share their internal clock signals with external components. The STM32H573 supports this via Microcontroller Clock Outputs (MCO) on two GPIO pins: PA8 (MCO1) and PC9 (MCO2). Whether you’re debugging clock issues or
How to Generate Clock Output (MCO1/MCO2) on STM32H573 Read More »
Interfacing an external flash memory with a microcontroller is a common task in embedded systems to minimize unnecessary access to the MCU’s internal flash. Embedded firmware developers often use external flash for data logging, firmware storage, and IoT applications. External flash memory often includes communication interfaces such as I2C, SPI, or QSPI. System architects ensure
How to Interface External Flash with QSPI Using Bit Banging: A Step-by-Step Guide Read More »
Flash memory is a widely used non-volatile storage technology found in microcontrollers, SSDs, USB drives, and many other electronic devices. Non-volatile means it retains data even when the power is turned off. However, there is an important limitation: Flash memory erase before write is mandatory. This means that before you can write new data to
Why flash memory must be erased before writing Read More »
MCU startup code is the low-level code that executes during the early stages of MCU initialization after a reset. On a Cortex-M device, the processor begins the reset sequence by loading the initial Main Stack Pointer (MSP) and the reset handler address from the vector table. Depending on the MCU’s boot architecture, a boot ROM or
MCU Startup Code: What Happens Before main() Runs (ARM Cortex-M Example) Read More »
Understanding the linker script (.icf file) is crucial for achieving precise control over the memory layout when working with STM32 microcontrollers in IAR Embedded Workbench. Whether you’re a beginner just trying to flash an LED or an advanced embedded developer optimizing bootloaders, this guide walks you through IAR linker scripts—from the basics to the advanced
IAR Linker Script for STM32: Complete Guide (Basic to Advanced) 🛠️ Read More »