| ??? 01/19/10 12:34 Read: times |
#172593 - I see. Responding to: ???'s previous message |
Andy Neil said:
What is the point in absolutely-locating it? Seems unnecessary to me... Frieder Ferlemann said:
The point is to tell the compiler that it's located at a 256 byte boundary. So it does not need a full 16 bit addition of array base address and index but instead can directly load dpl with the high byte of the address and dpl with the index. I see - good point. AFAIK you'd tell Keil the absolute location of the variable at the linking stage (which is to late for code generation so the 16 bit addition has been generated). C51 does have the _at_ keyword to do it at compile time So out of the box Keil probably cannot do it. It has the opportunity - I have to idea whether it will take advantage of it! |
