| ??? 10/23/10 07:44 Read: times |
#179298 - What is your VCC ramp? Responding to: ???'s previous message |
Goran Igic said:
I need to distinguish between power-up reset and hard reset (pin reset).
It looks that POF bit in PCON register doesn't do a job. In most mcu-s I've seen, the POF hardware to work reliably the VCC ramp must have be relatively fast; and/or in case of switching off-on, VCC must drop below a certain threshold before it starts to rise again. While the 'V51Rx2 datasheet does not specify these conditions, I believe these may hold and make POF unreliable if you are not aware of them. You might need to contact NXP to clarify these items. You might also want to have a look at the SST89E516 (which IMHO is the same chip) datasheet, if it is more clear in this respect. JW |
| Topic | Author | Date |
| P89V51 power up | 01/01/70 00:00 | |
| are you missing this? | 01/01/70 00:00 | |
| POF flag | 01/01/70 00:00 | |
| 'V' in the name is not revision... | 01/01/70 00:00 | |
| What is your VCC ramp? | 01/01/70 00:00 | |
| Power UP | 01/01/70 00:00 | |
| I've been harping on this for years ... | 01/01/70 00:00 | |
| Not nobody | 01/01/70 00:00 | |
| RC | 01/01/70 00:00 | |
| Have you considered the effect of Vcc rise/fall time? | 01/01/70 00:00 | |
| Vcc rise/fall time | 01/01/70 00:00 | |
Try trick | 01/01/70 00:00 |