hi,
I have asked to write c program for HDMI EDID test cases in set top box....i am new to c programming..i dont know how to write c program for testing set top box which respond to all kind of resolution...that means the set top box have to convert the sourse signal resolution to display device resolution....if you know any small idea about it it will be useful for me
Are you coding a program which will run on the set top box? If so, you will need a cross compiler for that target.
You will need to find out how to upload a compiled binary to the set top box and how to make it execute there.
You will also need to find out which OS, if any, the set top box runs (commonly embedded linux) and which CPU it uses. (PPC is common in chinese Dreambox clones, also ARM is popular. I have seen MIPS too.)
One good way of getting a cross compiler is to use Cross Tool by Dan Kegel.
As Rup statet there are two ways of doing the tests: A: Leaving your settop-box as is and faking the inputs to your settop-box by interfacing with an external device which does the fake inputs and test the output. This is, as far as I know, sometimes referred to as black box testing B: When you have can modify the source code of your settop-box you can instrument this code to do automatic test. This is referred to as Unit Test or white box test
A good starting point to get an idea of unit testing is FitNesse or JUnit. If you need to do unit testing in C and it is requiered that your tests run on the target you may be interested in Maestra from MacroExpressions which is free and also does code coverage analysis, which is required mostly, but not only, in safety critical systems.
[1] hxxp://www.fitnesse.org/ [2] hxxp://www.junit.org/