Interrupts - event driven devices, Computer Graphics

Assignment Help:

Interrupts - Event driven devices

Interrupts: An option to polling is the interrupt feature. The device sends an interrupt signal to the processor while an event happens. The processor breaks from its usual execution and executes several special interrupt-handling routine or task.

After complete the task, the control returns to the important program. To handle conditions while more than one event happens, various priorities are allocated to tasks hence higher priorities tasks may interrupt tasks of lower priority.

Some events may arise before the program is prepared for them. While more than one event occurs, the relate information is entered in the event queue. A polling loop can be utilized to check the status of the event queue. The event queue can after that pass input data from the polling task to the main program in the accurate order. The main program takes events off the head of the queue and raises the suitable process. The devices require not be checked frequently for occurrence of events. Such devices can interrupt although the processor being unaware of this.

Two types of light pen interrupts may arise. If the user points that pen at an item upon the screen to choose it, as in figure (a) of Light Pen Application, a selection interrupt arises. If the user is positioning along with the pen, as in figure (b) of Light Pen Application, a pattern termed as tracking pattern in displayed along the pen's tracking interrupts and movement arise when the pen observes the tracking pattern.

Modified versions of the light pen may also be utilized to draw lines, read barcodes or perform transformation operations on things on a tablet or on the screens.

 


Related Discussions:- Interrupts - event driven devices

State the areas of use of data goggles, State the Areas of use of data gogg...

State the Areas of use of data goggles Entertainment   Used in television/films as special effects (for example "holodeck" in Star Trek: The Next Generation and Brazilian

Explain the advantage and disadvantage of raster crt, Explain the advantage...

Explain the advantage and disadvantage of Raster CRT Advantages Allows solids, not just wireframes Leverages low-cost CRT technology (i.e., TVs) Bright, i.e.

Removing polygons hidden through a surrounding polygon, Removing Polygons H...

Removing Polygons Hidden through a Surrounding Polygon: The key to capable visibility calculation lies actually a polygon is not visible whether it is in back of a surrounding

Computer arthcther, How many 128 x 8 RAM chips are needed to provide a memo...

How many 128 x 8 RAM chips are needed to provide a memory capacity of 4096 16 bits?

Define emissive and non-emissive displays, What do you mean by emissive and...

What do you mean by emissive and non-emissive displays?  The emissive display changes electrical energy into light energy. The plasma panels, thin film electro-luminescent disp

Define refresh rate and refresh buffer, Refresh Rate: refreshing on raster...

Refresh Rate: refreshing on raster - scan displays is carried out at the rate of 60 to 80 frames per second, although some system are designed for higher refresh rates. Sometimes,

Offset lithography printing, QUESTION A trainee designer, Susan, joins ...

QUESTION A trainee designer, Susan, joins your place of work. During a workshop, you are asked to present on printing procedures and agencies in Mauritius. Susan asks you what

Flash - software to generate computer animations, Flash - software to gener...

Flash - software to generate computer animations Flash: Learning Macro-Media's Flash can quite complicated, although you can do almost anything along with it. You can devel

B-spline curves - uniform b-splines and de boor algorithm, B-spline curves ...

B-spline curves are piecewise smooth polynomial curves.  B-spline curves are defined over an interval which has been partitioned into sub-intervals. On each subinterval B-sp

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd