| ??? 02/25/06 06:01 Read: times |
#110748 - EPROM, EEPROM, and flash Responding to: ???'s previous message |
Andy Peters said:
Ashwin V said:
Is a eeprom version of 8051 available in the market????? The 8751 (and later 87C51) is the classic UV-erasable EPROM version of the 8051. I suppose it's still available, but UV-erasable parts in general are obsolete--why bother when you can do in-circuit programming with flash-based parts? The 8751/87C51 are indeed classic UV-erasable devices, but they are EPROM parts, not EEPROM parts. By definition, EEPROM is "electrically erasable programmable read-only memory", which is not what's in the parts you mentioned. And that raises the question why the original poster requests EEPROM instead of flash. Andy Peters said:
Ashwin V said:
The 8051 trainer kits used in our college stores and runs the code which we write in the external ram(no miskate done:it's RAM not ROM).The data sheets of the kit says that the ext ram address is 4000h to 5fffh. The monitor program occupies 4000h to 4100h of this ram and so user ram area is 4100h to 5fffh. Every time assemble a new test-code on the computer, we send it through the rs232 and load it from 4100h onwards. I didn't quite understand how this works can anyone help???? Sounds like your trainer has implemented an "EPROM emulator." Back in the old days, an EPROM emulator was a device with dual-port RAM that fit into a 27Cxxx socket. You could load the "EPROM" from a computer or whatever; the 8051 sees it as a ROM in the usual way. This made burn-and-crash debugging less painful, as you didn't have to waste half an hour waiting for your EPROM to erase (if you didn't have a pile of EPROMs lying around). But as I said, it's obsolete. -a Maybe it's just von Neumann-wired RAM? --Sasha Jevtic |
| Topic | Author | Date |
| eeprom version of 8051 | 01/01/70 00:00 | |
| re: eeprom version of 8051 | 01/01/70 00:00 | |
| EPROM, EEPROM, and flash | 01/01/70 00:00 | |
| EPROM, EEPROM, and flash | 01/01/70 00:00 | |
89s8252 | 01/01/70 00:00 | |
| von Neumann-wired RAM | 01/01/70 00:00 | |
| Look up old Intel databook( ~198x) | 01/01/70 00:00 | |
| Look at the scehmatic | 01/01/70 00:00 | |
| use modern devices | 01/01/70 00:00 | |
| other modern devices | 01/01/70 00:00 |