| ??? 10/10/14 22:41 Modified: 10/10/14 23:30 Read: times |
#190361 - Still no Vcc ? Responding to: ???'s previous message |
Still no Vcc ? 12MHz means AT89LP51Rx2 is fine.
(only if you were using 24~33MHz would there be issues) Oliver Sedlacek said:
We can't find the source (written 20+ years ago in a different country, original engineers retired or made redundant), so 'same binary' is really the key thing. You could dis-assemble and rebuild to at least know what resource it does use. eg it may not use the PCA, or 4 level interrupts. Oliver Sedlacek said:
As we need to spin the board, PLCC/QFP is a realistic option which we would go for as NXP are still showing support. I'm not sure whether it's an FA or FB as the BOM still calls for an Intel part. I do know that it's got 4kB of PROM, and I would expect it to be a 12 clocker. The 87C51FA/FB/FC was 8K/16K/32K, with the PCA and the 4 Level int, IIRC (your design many not be using the PCA or 4 Level INT ) QFP in OTP is not an ideal combination, but QFP in flash is more practical. Depends how much longer you want/expect the product to last ? NXP are likely to EOL an old OTP process sometime, and I'd put Atmel as the best long-term source with the AT89LP51Rx series a 'modern' choice. These parts also come boot-loader ready. |
| Topic | Author | Date |
| Any suggestions for P87C51F replacement? | 01/01/70 00:00 | |
| how critical is ... | 01/01/70 00:00 | |
| What MHz, Vcc, & exact part code ? | 01/01/70 00:00 | |
| more info | 01/01/70 00:00 | |
| Still no Vcc ? | 01/01/70 00:00 | |
| what about using an adapter? | 01/01/70 00:00 | |
| 5V VCC | 01/01/70 00:00 | |
| the rumors of the demise of the '51 are greatly exaggerated | 01/01/70 00:00 | |
| New 8051's | 01/01/70 00:00 | |
| RE: New 8051's | 01/01/70 00:00 | |
rejoice | 01/01/70 00:00 |