| ??? 12/07/04 21:57 Read: times |
#82726 - port pin can sink and source Responding to: ???'s previous message |
Sorry for jumping in into this obviously closed thread. But all ports pins of 8051 derivatives except these of P0 source current for the 2 oscillator periods after a 0-to-1 transition. So, if a program writes zeroes and ones alternatively to a port register with the appropriate output pin shortened to GND there will be a current peak of several 10 mA per port pin. So, do not write 0 to a port pin that you intend to use as an input. You can either damage the uC or the IC that drives the signal to the uC.
Regards, Harald |
| Topic | Author | Date |
| I/O read doubt.. | 01/01/70 00:00 | |
| I/O read | 01/01/70 00:00 | |
| got the idea. | 01/01/70 00:00 | |
port pin can sink and source | 01/01/70 00:00 | |
| look at the sachmatic in "the bible" | 01/01/70 00:00 |