1
H th ng nhúngệ ố
Th c sĩ Lê M nh H iạ ạ ả
Embedded Systems
2
Lesson 8 :THE DARK SCREEN
Motivation:
•Generating the composite video signal
•Using the Output Compare modules
•Memory allocation
•Image serialization
•Building the video module
•Testing the video generator
•Measuring performance
•The dark screen
•A Test Pattern
3
Flight plan
•In this lesson we will consider techniques to
interface to a TV screen or, for that matter, to any
display that can accept a standard composite video
signal.
•It will be a good excuse to use new features of
several peripheral modules of the PIC24 and
review new programming techniques.
•Our first project objective will be to get a nice
dark screen (a well-synchronized video frame), but
we will soon fill it up with several entertaining
graphical applications.
4
Preflight checklist
•MPLAB® IDE,
•MPLAB C30 compiler and the
•MPLAB SIM simulator,
•Explorer16 demonstration board and the
•MPLAB ICD2 In Circuit Debugger
5
The flight
•There are many different formats and standards today
in use in the world of video, but perhaps the oldest and
most common one is the so-called “composite” video
format.
•This is what was originally used by the very first TV
sets to appear in the consumer market, and today it
represents the minimum common denominator of
every video display, whether a modern high-definition
flat-screen TV of the latest generation, a DVD player,
or a VHS tape recorder.