Embedded Systems Final

C Embedded Systems Flashcards

What is Embedded C?

Embedded C is an extension of C language and it is used to develop microcontroller based applications.

What is C language?

C is a general-purpose programming language, which is widely used to design hardware-based applications.

Global Variable

A global variable exists in the program for the entire time the program is executed. Global variables are created starting address 0x0200.

Local Variable

A local variable is created when the function is executed, and once the execution is finished, the variable is destroyed. Local variables are kept in the stack (0x0400).

Executable File

The executable file (.out) that is output from the build process is the file that can be loaded and executed on a target device.

Header File

A header file is a file with extension .h which contains C function declarations and macro definitions to be shared between several source files.

#include files and why you would want to have multiple .c source files for a program.

(1) It speeds up compile time.

(2) It keeps your code more organized.

(3) It allows you to separate interface from implementation.

Static Library

A static library is a compiled object file containing all symbols required by the main program to operate (functions, variables etc.) as opposed to having to pull in separate entities.

#ifndef

checks whether HEADERFILE_H is not declared

#define

will declare HEADERFILE_H once #ifndef generates true

#endif

is to know the scope of #ifndef i.e end of #ifndef

Source Files

the files that contain the code that gets compiled. The implementation of your algorithm is contained in a source file.

What is Capture?

A timer capture will store the current value of the timer into one of the

capture/compare registers upon a triggering event.

The timer has four modes of operation:

stop, up, continuous, and up/down.

The SYNC bit enables…

synchronous capture, which means the capture event is

synchronized with the timer clock.

What is Compare?

The compare mode is selected when CAP = 0. Compare mode is used to

generate PWM output signals or interrupts at specific time intervals.

PWM meaning

Pulse Width Modulation

PWM Device

It’s a device that breaks up a DC voltage into pulses which can be changed to our needs. When

we change the width of the pulses, we are modulating them

Serial Communication

In serial communication the data bits are transmitted serially one by one i.e. bit

by bit on single communication line. Less costly.

Parallel Communication

In parallel communication, all the bits of data are transmitted simultaneously

on separate communication lines. Used for shorter distance.