| ??? 04/03/10 06:39 Modified: 04/03/10 07:08 Read: times |
#174801 - Reset Responding to: ???'s previous message |
This and some other examples I have found tend to connect the reset pin of the MCU to a capacitor toward the Vcc and a resistor toward ground. Why is this? when this pin is high for 2 cycles the chip resets right? why is this needed here?
The 8052 is reset at power on by holding the reset pin low after power on which does two things,three even,it allows the power supply to settle and it allows the crystal oscillator to start up and the internal registers to go to a known state. Using the capacitor/resitor is a very unreliable method used in early designs which has now been superceeded by the use of a power on reset supervisor which will perform the reset correctly and will reset the processor when the power supply goes below a set level. A search on here will reveal long and detailed discussions about such devices. |
| Topic | Author | Date |
| New with MCUs need a little help. | 01/01/70 00:00 | |
| Hi | 01/01/70 00:00 | |
| Some answers but now concerns | 01/01/70 00:00 | |
| Normally very weak source | 01/01/70 00:00 | |
| Can't find that detail | 01/01/70 00:00 | |
| Not many 805x's have push-pull outputs. | 01/01/70 00:00 | |
| Reset | 01/01/70 00:00 | |
| SDCC | 01/01/70 00:00 | |
| Books | 01/01/70 00:00 | |
| Electronics | 01/01/70 00:00 | |
| first read "the bible" | 01/01/70 00:00 | |
| Maybe not First? | 01/01/70 00:00 | |
| Rickey? | 01/01/70 00:00 | |
| I am new, Just somthing I wanted to do. | 01/01/70 00:00 | |
| Dead links | 01/01/70 00:00 | |
| No you are right | 01/01/70 00:00 | |
| hrm | 01/01/70 00:00 | |
| Argh!!! | 01/01/70 00:00 | |
| It's a highly dynamical thing... | 01/01/70 00:00 | |
| a reset writeup, but you don't want to read it now | 01/01/70 00:00 | |
| You mean this one? | 01/01/70 00:00 | |
Thanks | 01/01/70 00:00 | |
| not dead, just incorrectly copied | 01/01/70 00:00 | |
| Thanks | 01/01/70 00:00 |