Imagecraft c compiler and development environment for the atmel avr

C LIBRARY AND STARTUP FILEOverriding a Library FunctionYou can write your own version of a library function. For example, you can implementyour own putchar() function to do interrupt driven IO (an example of this isavailable in the c:\iccv8avr\examples.avr directory) or write to an LCD device.The library source code is provided so that you can use it as a starting point. You canoverride the default library function using one of the following methods:You can include your function in one of your project files. The compiler system willnot use the library function in this case. Note that in this case, unlike a librarymodule, your function will always be included in the final program output even ifyou do not use it.You may create your own library. See Librarian for details.You may replace the default library version with your own. Note that when youupgrade to a new version of the product, you will need to make this replacementagain. See Librarian for details on how to replace a library module.