| ??? 06/15/09 15:18 Read: times |
#166098 - xdata will just be whatever EXTRAM says Responding to: ???'s previous message |
Let me assume that you just have a "few" peripheral devices that you want to memory-map. You only use the internal XRAM for program variables. You do not have conventional external RAM.
Then you just set and clear the EXTRAM bit whenever you access your peripherals. The compiler does not know or care which memory you are accessing. So your regular program is always set up for the internal XRAM. It all really depends on how fast or often you need to access your peripherals. You may find it as easy to access via ordinary port lines. But whichever way you do it, you need to ensure that only one CPU accesses one peripheral at a time. David. |
| Topic | Author | Date |
| AT89c51cc01 and External memory (keil/C51) | 01/01/70 00:00 | |
| Cross posted | 01/01/70 00:00 | |
| Is your problem with FLIP ? | 01/01/70 00:00 | |
| No, think it's keil compiler | 01/01/70 00:00 | |
| Sounds like an error in the data sheet | 01/01/70 00:00 | |
| bible time | 01/01/70 00:00 | |
| Itterations | 01/01/70 00:00 | |
| just won't get flashed into the µc?? | 01/01/70 00:00 | |
| The compile will compile what you tell it | 01/01/70 00:00 | |
| RE: your example does not access any xdata at all | 01/01/70 00:00 | |
| RE: Rob Stoffels said:I think there is something that needs | 01/01/70 00:00 | |
| Going to try something different | 01/01/70 00:00 | |
| Broken Boards? | 01/01/70 00:00 | |
| Memmory mapping question/ Bord fixed | 01/01/70 00:00 | |
| If I read this correctly | 01/01/70 00:00 | |
| Missunderstanding | 01/01/70 00:00 | |
| xdata will just be whatever EXTRAM says | 01/01/70 00:00 | |
do you have any external RAM? | 01/01/70 00:00 | |
| CC03 is working | 01/01/70 00:00 |