| ??? 04/30/09 14:37 Read: times |
#164964 - You have keen eyesigt. Responding to: ???'s previous message |
Shankara Rao said:
Thanks every one for their responses. I will try to implement them and get back. However I am not still convinced why all the outputs behave in an inconsistent way. I have observed different outputs switch on at different times.
Thanks for your time Shankara Rao Then you have a serious problem with your initialisation code. The 8051 should be in a defined state during RESET. The 8051 should come out of RESET in a defined state. You design your hardware so that it is safe during power-off and during RESET. Normally by using pull-ups and active-low outputs. If your initialising routines produce any unsafe states, you have coded them wrong. If you can observe asynchronous output, you must have very good eyesight, and the unsafe states are valid for a significant amount of time. I would suspect brown-out detectors or watchdog detectors. i.e. your hardware. David. |
| Topic | Author | Date |
| Outputs during poweron | 01/01/70 00:00 | |
| Inverted logic | 01/01/70 00:00 | |
| if they were strong enough | 01/01/70 00:00 | |
| depends | 01/01/70 00:00 | |
| You could use an OR-gate... | 01/01/70 00:00 | |
| why not just an inverter? | 01/01/70 00:00 | |
| how about an inverting version? | 01/01/70 00:00 | |
| suggestions | 01/01/70 00:00 | |
| You have keen eyesigt. | 01/01/70 00:00 | |
yes, but the overlooked fact is .. | 01/01/70 00:00 | |
| 3 possibilities | 01/01/70 00:00 |