| ??? 02/21/07 13:35 Read: times |
#133413 - No Responding to: ???'s previous message |
to update an old product developped in 1990 with ext 64k PROM 32k RAM ..., we have tried to use
P89C51RD2, AT89C51RD2 and finally P89V51RD2. Our need is to use ext PROM for code and internal flash for datas. You could'nt do that before, why so now With P89C51RD2and AT89C51RD2 it is possible to use IAP functions from external code because the EA pin is latched after the reset. No What I would suggest would be to replace the external PROM with a flash chip configured as data memory and using a port bit to select between RAM and external Flash. Erik |
| Topic | Author | Date |
| 89v51 IAP using ext code PROM | 01/01/70 00:00 | |
| No | 01/01/70 00:00 | |
| how do you do that? | 01/01/70 00:00 | |
| It runs on AT89C51 and P89C51 | 01/01/70 00:00 | |
| Internal IAP with external code | 01/01/70 00:00 | |
ah so... | 01/01/70 00:00 |