MCU Startup Process The MCU startup process refers to the sequence between: MCU reset –> main(). After the MCU is reset, it willstart executing from the reset vector,initialize the Stack pointer to point to the end of the designated Stack area, and thencall the __low_level_init function for related initialization. For detailed processes, please refer to … Read more
1. Where does the MCU read code when it first starts up?After the CPU is powered on, it is designed to read code from address 0x00000000; it first reads two words in succession, which are the initial value of the stack pointer and the address of the reset exception handler; then it jumps to execute … Read more
For those new to microcontrollers, it is common to start writing code from the main() function — as if the microcontroller will obediently execute instructions as soon as main() runs. However, before the main loop (the loop logic within the main() function) starts, the microcontroller must first complete a series of “preparatory tasks”, similar to … Read more
In embedded development, many engineers often wonder: after powering on the program, how are global and static variables initialized? Is the underlying memory operation logic the same from Keil MDK-ARM to the GCC cross-toolchain? Today, we will break down this core issue and understand the complete process from chip power-up to the execution of the … Read more
For embedded developers, the MCU acts like a tireless little steward, responsible for directing electronic devices to complete various tasks. But have you ever thought about how this “little steward” is awakened from a completely “asleep” state to gradually enter a working state the moment you power on the device? The startup process behind this … Read more
Line-by-Line Analysis of the Linker File In the previous article, we analyzed the startup file, and here we will supplement an important C function within the startup file. /** * @brief Setup the microcontroller system * Initialize the FPU setting, vector table location and External memory * configuration. * @param None * @retval None */ … Read more
1 Introduction To understand how microcontrollers execute programs, it is essential to first comprehend the components of a microcontroller. This article uses the 80C51 microcontroller as an example to explain how programs run within a microcontroller. 2 Components of a Microcontroller The internal hardware structure of the 8051 microcontroller includes: Central Processing Unit (CPU): This … Read more
As a hardware engineer, have you ever encountered these issues: The circuit board shows no response after power is applied, like a “brick”. The program occasionally starts, but sometimes hangs. Peripheral initialization is abnormal, yet the code logic is correct. These issues stem from startup process anomalies 80% of the time! Let’s learn about the … Read more
Today, let’s delve into a seemingly basic yet often overlooked topic — what exactly happens from the moment you press the reset button until your <span>main()</span> function begins execution? Overview of the Startup Process: The Journey of System Awakening Imagine your MCU as a robot just awakened. It needs to get dressed (load the stack), … Read more
Today, let’s delve into a seemingly basic yet often overlooked topic — what exactly happens from the moment you press the reset button until your <span>main()</span> function begins execution? Startup Process Overview: The Journey of System Awakening Imagine your MCU as a robot just awakened. It needs to get dressed (load the stack), understand its … Read more