| ??? 01/16/13 20:30 Read: times |
#189202 - reset is inverted Responding to: ???'s previous message |
there is a HC14 connected to have the inverted reset needed for other devices.(HC574, HC259
I measure a clear reset pulse on the µC reset pin I have 1 chip out of 4 that almost always starts, but most of them don't do this. I also have 3 batches : samples ( 2011 ), datestamp 1230 and 1237, the latter just bought at digikey The board has external RAM, and some HC541, H574 on the databus. Something could get messed up by an internal race condition ? |
| Topic | Author | Date |
| Reset issue with new Atmel AT89LP51ED2 | 01/01/70 00:00 | |
| Do never use a µC from which only a preliminary... | 01/01/70 00:00 | |
| configuration settings | 01/01/70 00:00 | |
| what about negative reset? | 01/01/70 00:00 | |
| good idea but | 01/01/70 00:00 | |
| Some things to check... | 01/01/70 00:00 | |
| also try no LM810 at all | 01/01/70 00:00 | |
| reset is inverted | 01/01/70 00:00 | |
| no strange signals | 01/01/70 00:00 | |
| Extra modes ? | 01/01/70 00:00 | |
| pull-up on PSEN solves the problem | 01/01/70 00:00 | |
| small capacitor ? | 01/01/70 00:00 | |
| small capacitor | 01/01/70 00:00 | |
| side-stepping the problem? | 01/01/70 00:00 | |
| SST could be an option | 01/01/70 00:00 | |
| final status AT89LP51ED2 reset | 01/01/70 00:00 | |
| Clarifies | 01/01/70 00:00 | |
| loads on PSEN | 01/01/70 00:00 | |
| An isolated PSEN works fine ? | 01/01/70 00:00 | |
| GAL causes problem | 01/01/70 00:00 | |
| ATF16V8CZ has Pin-keeper | 01/01/70 00:00 | |
| 'Z' indeed | 01/01/70 00:00 | |
| ATF16V8BQL has Icc of ~1.5mA | 01/01/70 00:00 | |
'BQL' version could be an option | 01/01/70 00:00 |