| ??? 12/22/05 14:30 Read: times |
#105746 - reset cap Responding to: ???'s previous message |
Dear Shivani,
> 1. there is nothing in hardware only a at89c2051 > mcu with reset cap ,+5v supply and ground. Some additional tips: - do you have the power supply properly decoupled? - a 100nF ceramic capacitor across VCC and GND directly at the AT89C2051's pins or as close as possible. Adding one extra might never harm... - get a proper reset circuit, such as TL7705 or MAX810 and alike. These beasts ('51s) tend to behave unpredictibly if you don't provide them nice and clean reset pulse for a number of valid crystal clocks (also some crystals start slowly)(*). If you don't have one handy, you can try some external clean pulse source; for starting perhaps try experimenting with the capacitor value. Also, check the content of the micro AFTER you placed it into the circuit and it did not work - with improper reset it might happen that the FLASH content gets corrupted. Jan Waclawek (*) I have a story for this, one AT89C2051 started quite consistently at address 0112h when the reset circuit produced a short spike after a longer pulse... |
| Topic | Author | Date |
| this code is not working | 01/01/70 00:00 | |
| You solved it! | 01/01/70 00:00 | |
| overreaction | 01/01/70 00:00 | |
| Humility ? | 01/01/70 00:00 | |
| Call it cultural difference... | 01/01/70 00:00 | |
| Sounds familiar | 01/01/70 00:00 | |
| thanks Jan Waclawek | 01/01/70 00:00 | |
| Keil's startup.a51 | 01/01/70 00:00 | |
| hex seems OK | 01/01/70 00:00 | |
| re hex seems OK | 01/01/70 00:00 | |
| And the switch? | 01/01/70 00:00 | |
| and switch | 01/01/70 00:00 | |
| Try a pull-up | 01/01/70 00:00 | |
| switch function | 01/01/70 00:00 | |
| Not at all | 01/01/70 00:00 | |
| reset cap | 01/01/70 00:00 | |
| yeah | 01/01/70 00:00 | |
| It can! | 01/01/70 00:00 | |
| points | 01/01/70 00:00 | |
| Some suggestions | 01/01/70 00:00 | |
| nope | 01/01/70 00:00 | |
| Use LEDs | 01/01/70 00:00 | |
| ok let me follow | 01/01/70 00:00 | |
| That sounds good ! | 01/01/70 00:00 | |
| try this code | 01/01/70 00:00 | |
and what good will that do? | 01/01/70 00:00 | |
| How? | 01/01/70 00:00 | |
| capital | 01/01/70 00:00 | |
| Thanks! | 01/01/70 00:00 | |
| I did the same thing recently | 01/01/70 00:00 | |
| At least... | 01/01/70 00:00 | |
| HORSEFEATHERS | 01/01/70 00:00 | |
| i think yopu didn't got the message | 01/01/70 00:00 | |
| of course it is not | 01/01/70 00:00 | |
| It's easy to fix the code | 01/01/70 00:00 | |
| no, he does not | 01/01/70 00:00 | |
| wrong suggestion | 01/01/70 00:00 | |
| it DOES NOT write to R0 | 01/01/70 00:00 | |
| RE: it DOES NOT write to R0 | 01/01/70 00:00 | |
| why the continued discussion | 01/01/70 00:00 | |
| Time zone | 01/01/70 00:00 | |
| just another guess | 01/01/70 00:00 | |
| She is most likely from India | 01/01/70 00:00 | |
| Irony | 01/01/70 00:00 | |
| Help me | 01/01/70 00:00 | |
| re help me | 01/01/70 00:00 | |
| What happens if? | 01/01/70 00:00 | |
| i will see | 01/01/70 00:00 | |
| "mov @r0,#00h" by "NOP, NOP"? | 01/01/70 00:00 | |
| A good idea | 01/01/70 00:00 | |
| nothing postive | 01/01/70 00:00 | |
| RAM fill ? | 01/01/70 00:00 | |
| re ram fill | 01/01/70 00:00 | |
| Simulator. | 01/01/70 00:00 | |
| Is the CPU really running? | 01/01/70 00:00 | |
| mov p1,r0 | 01/01/70 00:00 | |
| last hope | 01/01/70 00:00 | |
| Tell this first | 01/01/70 00:00 | |
| let me clear | 01/01/70 00:00 | |
| pull ups | 01/01/70 00:00 | |
| re pull ups | 01/01/70 00:00 | |
| a word on pull ups | 01/01/70 00:00 | |
| What to say for that ignorance? | 01/01/70 00:00 |