Robert A Duff wrote: > > "Rainer Aigner Tel. XXXX" writes: > > > Up to here everythings fine. > > Now, my question: How can I make sure that the compiler uses the right > > assembler for load and store operations? > > I'm not sure exactly what you're asking, but you might want to look up > the Atomic and Volatile pragmas. > > - Bob Hello Bob, all right I thougth of that too, but maybe I rearange the question: I got two types one is 8-Bit and the other is 16-Bits wide. I make two variables, one of eache type, and tell the compiler where they are located (eg. registers). Now I make a simple read from both variables to a temp variable of each. (for modify and write back). And I want to make sure, that a read with the 8-bit type is performed by a "load byte", and the 16-bit type by a "load halfword" assembler statement. The pragmas You told me, would do (correct me if I didn't get right) volatile: make sure that the compiler doesn't opimize them out. eg. two consecutive writes and a subsequent read. atomic: Is trying to perform the load and store in a single assembler statment. That okay, but it's only half the rent. In addition to this I want that the compiler thates care of the size. unfortunatly the compiler I have to use doesn't work with the pragma volatile (still some bug). thank You for the answer. cu rainer