| ??? 04/26/05 03:14 Read: times |
#92348 - PCMCIA Cards.... Responding to: ???'s previous message |
PCMCIA Cards interface, of which the Compact Flash is a derivative, does have the concept for a memory mapped mode. For a CF card that supports this mode (not all do) the memory is but a small window of some 2K bytes in size. (or 4K/8K I don't recall right off the head). If you were to use this as directly executable code space it would have to be mapped as external code space of the 8051. It is possible but any programs using the small page size would need a supporting base or common page in another part of the 8051 address space. In effect you could anticipate the possibility of using a CF card as a bank switched 8051 type application program store. But in the very small 2K pages.
It would be terribly inefficient and is certainly not worth the bother. You would be far better off using the CF card as a disk drive and a large FLASH microcontroller such as a SiLabs C8051F12x (128K bytes) and block moving the desired code from the CF card into say a 32K page of the microcontroller flash. In effect this could be pretty much implemented as a form of IAP (In Application Programming). Michael Karas |
| Topic | Author | Date |
| Compact flash for code memory? | 01/01/70 00:00 | |
| not really | 01/01/70 00:00 | |
| Hmmmm | 01/01/70 00:00 | |
| just visualize | 01/01/70 00:00 | |
| no filesystem | 01/01/70 00:00 | |
| its a disk | 01/01/70 00:00 | |
| Winhex does! | 01/01/70 00:00 | |
| Somebody is! | 01/01/70 00:00 | |
| Low-level disk editing... | 01/01/70 00:00 | |
| CF is not a memory | 01/01/70 00:00 | |
| A word of caution... | 01/01/70 00:00 | |
| memory mapped mode | 01/01/70 00:00 | |
| Mem mapped mode | 01/01/70 00:00 | |
| File system | 01/01/70 00:00 | |
| PCMCIA Cards.... | 01/01/70 00:00 | |
| NO memory-like access! | 01/01/70 00:00 | |
| Flash Cards with "2K Attribute" | 01/01/70 00:00 | |
| no, no, NO | 01/01/70 00:00 | |
| Jan, You are WRONG and RIGHT | 01/01/70 00:00 | |
| CF or not CF | 01/01/70 00:00 | |
Sour Lemons | 01/01/70 00:00 | |
| Compact Linear Flash Cards | 01/01/70 00:00 | |
| just a thought | 01/01/70 00:00 |