| ??? 10/03/05 15:51 Read: times |
#101855 - Please explain further Responding to: ???'s previous message |
"Programm start from AT89C51ED2 and lock bit 2 is set."
I'm curious - why would you have set the lock bit that prevents external execution? Or should I assume that somebody else has set the lock bit? Why do you care if the external EEPROM is present? If you need more than the 64k internal code space then presumably your system cannot function without code contained in the external EEPROM, in which case being able to detect the presence of that EEPROM isn't going to help? If it can function without the EEPROM, then the EEPROM must contain data rather than code, in which case you can follow part of Peter's suggestion and map the device as external RAM rather than code space. If you were to explain why you are trying to do what you are trying to do then perhaps someone will come up with an alternative approach. |
| Topic | Author | Date |
| AT89C51ED2 and external EEPROM | 01/01/70 00:00 | |
| If serial, try a write and a read, if pa | 01/01/70 00:00 | |
| some comments | 01/01/70 00:00 | |
| why "of course" most is serial | 01/01/70 00:00 | |
| I don't need 128K programm memory | 01/01/70 00:00 | |
| if it is not used, you can not detect it | 01/01/70 00:00 | |
| I must to do it by software | 01/01/70 00:00 | |
| You should have thought of that before y | 01/01/70 00:00 | |
| Re: hardware required | 01/01/70 00:00 | |
| leave harvard structure! | 01/01/70 00:00 | |
| it depends | 01/01/70 00:00 | |
| no meaning | 01/01/70 00:00 | |
| Software solution | 01/01/70 00:00 | |
| Sure, but why? | 01/01/70 00:00 | |
| Ask Sebastian | 01/01/70 00:00 | |
| Please explain further | 01/01/70 00:00 | |
| some explayning | 01/01/70 00:00 | |
| Use other device | 01/01/70 00:00 | |
XDATA? | 01/01/70 00:00 |