| ??? 01/17/13 20:06 Read: times |
#189233 - small capacitor ? Responding to: ???'s previous message |
Koen De Ganck said:
PSEN : is loaded with 1 port, the traces are within 2 x 3cm (4 endpoints ) on a multilayer. OCD is disabled I put a pull-up of 100K on PSEN and it seems to be the solution. A higher value (1M ) should also work ( RC < 100µs ) Maybe the Atmel ship is more sensitive than the NXP version. Adding a small capacitor on a chip that resets well, make it 'fail' ( startup in bootloader ) Can you define 'small capacitor', and was that applied to PSEN ? To GND, or Vcc ? Was the '810 reset active still ? I measured a normal PSEN pin, source -27uA @ 5V |
| 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 |