| ??? 04/19/11 09:09 Read: times |
#181948 - Why 89CXX is different Responding to: ???'s previous message |
My conclusion is based only by experience. Without buffer it sometimes worked erratically and unreliable.
I read one of Jan Axelson's book about 8051, and she encourage the reader to always buffer the 89CXX ports with 74HC244, which I did and the result is better. I use 74HC245 instead merely for convenient PCB design. |
| Topic | Author | Date |
| AT89c55 Connection with ULN2803/4 | 01/01/70 00:00 | |
| There is a FAQ for that | 01/01/70 00:00 | |
| MAX1232 + some NORs | 01/01/70 00:00 | |
| #181903 - AT89c55 Connection with ULN2803/4 | 01/01/70 00:00 | |
| '595 Chip /OE | 01/01/70 00:00 | |
| Pull-downs... | 01/01/70 00:00 | |
| 89C55 connection with 2803 | 01/01/70 00:00 | |
| Why? | 01/01/70 00:00 | |
| Why is Atmel different? | 01/01/70 00:00 | |
| Why 89CXX is different | 01/01/70 00:00 | |
| Advice not understood | 01/01/70 00:00 | |
| You didn't answer the question! | 01/01/70 00:00 | |
| Answer | 01/01/70 00:00 | |
not necessarily because of AT89 | 01/01/70 00:00 |