| ??? 01/16/13 23:30 Read: times |
#189205 - Extra modes ? Responding to: ???'s previous message |
Koen De Ganck said:
- the ALE pin is toggling and the (external) X-tal runs, even if not started up
- resetting after a good start-up works fine - I have a bootloader which toggles a pin with LED, so I can check it easily - I do not see a big difference in using LM810 or not, only the reset pulse length is different ( 16ms <> 200ms ) -the X-tal is used just for internal clocking I have a (older) P89C51RD (NXP) as reference in the same board and same power supply, and it always starts correctly in any situation. I have no clue what is going wrong. If re-reset is always ok, it maybe one of the extra modes you are hitting ? Do you have any loads on PSEN, or the OCD pins ? ie The SW-Boot force mode, involves holding PSEN Low, on RST release To check this, is you have a serial link, send the unit a 'U' The inbuilt bootloader will echo 'U' as it auto-bauds. |
| 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 |