I am using functions, which returns structs. This shouldn't be a problem in C. And it works mostly. But are there contexts where this is not allowed? Maybe there a conflicts because those structs are returned by using registers? for example: typedef struct { unsigned char Byte_1; unsigned char Byte_2; } two_byz; two_byz f_a(void) { two_byz rueck; rueck.Byte_1 = 0xAA; rueck.Byte_2 = 0xBB; return ( rueck); } two_byz test; test = f_a(); Again: this example does work - mostly! But as i used this module in another program there was just no return value. It is really weird, the function then behaves like void f_a(void).
There is a discussion of bit-addressable stuff in the C51 UG on P65-66. Is there more that should be said there? I've used the tools for so long that this is second-nature to me now. Jon
Since you can not use the volatile keyword with the sf bits & registers, I would feel better if it was stated that these are implicitly volatile.