| ??? 07/10/07 06:46 Read: times |
#141666 - Think about it - nothing weird! Responding to: ???'s previous message |
John Hu said:
I found out after removing all the _at_ that I am able to declare more bdata. It's weird cuz I thought bdata is in the memory location of 20H - 2FH in the internal RAM. And I never declared anything in those locations. Y? Think about it: BDATA is part of DATA - therefore anything you define in BDATA also reduces the available space in DATA; IDATA overlaps DATA - therefore anything you define in the IDATA range 0x00-0x7F also reduces the available space in DATA, as I pointed out in your other thread: I said:
IDATA overlaps DATA
unsigned char idata Name[10] _at_ 0x68;This is within the DATA space - hence it could cause DATA to overflow (or to stop overflowing, if you remove it) Like Dan said, you should pay attention to that thread (it's not hard to filter out the noise). If you are using the SMALL Memory Model, the compiler will put all of your variables into DATA space unless you specifically tell it otherwise - hence adding/removing variables in BDATA, and/or adding removing variables in IDATA addresses 0x00-0x7F will affect the amount of DATA space available and is very likely to cause it to overflow (or to stop overflowing). There is nothing weird about this at all! |
| Topic | Author | Date |
| data declaration problem | 01/01/70 00:00 | |
| Look at the Map file! | 01/01/70 00:00 | |
| hmm... how? | 01/01/70 00:00 | |
| Think about it - nothing weird! | 01/01/70 00:00 | |
| So why did they do that? | 01/01/70 00:00 | |
| thanks andy~ | 01/01/70 00:00 | |
| advice on the usage of absolute addresses | 01/01/70 00:00 | |
| so how do i check? | 01/01/70 00:00 | |
| It should be documented! | 01/01/70 00:00 | |
| i see | 01/01/70 00:00 | |
| incomplete | 01/01/70 00:00 | |
| Pay attention! | 01/01/70 00:00 | |
| to what? | 01/01/70 00:00 | |
| Jojo's back | 01/01/70 00:00 | |
| please read the content in that link | 01/01/70 00:00 | |
| gaps | 01/01/70 00:00 | |
| ya... | 01/01/70 00:00 | |
| read my post above ... | 01/01/70 00:00 | |
| I got it now | 01/01/70 00:00 | |
How to make a gap | 01/01/70 00:00 | |
| Not a declaration problem! | 01/01/70 00:00 |