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So far Yasen Stoyanov has created 20 blog entries.

Bit Manipulation in C

Writing programs for embedded systems often requires the manipulation of individual bits. Below is a list of the most common operations. In the examples we are performing them on an unsigned long variable called ctrl_reg. Setting a bit We can set a bit using the bitwise OR operator (|): ctrl_reg |= 1UL << n; The [...]

By |2018-08-17T22:57:56+00:00February 2nd, 2018|Categories: Explained Simply|Tags: , , |0 Comments

Memory Types Used in Embedded Systems

Hardware memory is used for storing information. In the case of embedded systems that may be the program data ,the program code itself, event logging etc. There are many types of technologies used when creating memory cells and many ways to categorize them, but we can distinguish two major categories based on the memory reaction [...]

By |2017-11-21T19:09:53+00:00November 15th, 2017|Categories: Explained Simply|Tags: , |1 Comment

Exception Types in Microcontrollers

Exceptions are events that disrupt the normal execution flow of the program. When an exception occurs the processor handles it by usually executing dedicated piece of code called exception handler. Each type of exception can have its own exception handler. In some literature sources exceptions and interrupts are analyzed as two different things. Expeptions being [...]

By |2017-09-24T07:59:16+00:00September 24th, 2017|Categories: Explained Simply|Tags: , |0 Comments

Software and Hardware Breakpoints

A breakpoint is an intentional stopping place during an execution of a program. It is a powerful debugging feature allowing us to suspend the execution of the program at a certain point and examine the current values of variables and memory locations. The program can then be resumed from the exact point it was suspended. Adding or removing breakpoints [...]

By |2017-07-03T19:09:22+00:00July 3rd, 2017|Categories: Explained Simply|Tags: , |0 Comments

Build Stages of Embedded C Programs

We can generally define three levels of abstraction from the underlying hardware when we develop embedded programs: Machine Code  Assembly Language  High Level Language Machine code is the native language of the microprocessors (but it is not used for directly writing programs). So no matter at what level of abstraction we decide to write our [...]

By |2017-06-18T22:48:56+00:00June 18th, 2017|Categories: Explained Simply|Tags: , |0 Comments

Global and Local Variables in Embedded C Programs

There are two main concepts that have to be explained in order for us to fully understand the differences between global and local variables in C programs: Scope  -  determines the region of the program where a variable can be accessed Storage Duration - determines when a variable is created and destroyed (lifetime of the variable) [...]

By |2017-05-11T19:08:55+00:00May 11th, 2017|Categories: Explained Simply|Tags: , |0 Comments

Memory Layout of Embedded C Programs

The memory layout of C programs consists of several segments. The segments accessible to a user program are shown in the figure below:   Fig. 1 C program memory layout Code Segment (.text)   This segment stores the executable program code (the machine instructions). Variables defined with the const type qualifier can also be placed [...]

By |2017-05-11T06:13:51+00:00May 2nd, 2017|Categories: Explained Simply|Tags: , |4 Comments

The Boot Process of a Microcontroller

Overview Even though the boot process can be a complex sequence involving multiple steps it always starts with the same first step. When the power-on reset sequence is finished and the CPU comes out of reset, the program counter is pointing to the address of the reset vector (boot vector). This address contains the first instruction that [...]

By |2017-04-15T21:37:46+00:00April 15th, 2017|Categories: Explained Simply|Tags: , |1 Comment