| ??? 10/18/06 18:10 Read: times |
#126687 - what do you try to do Responding to: ???'s previous message |
hi,
Christoph Franck said:
I have an application where it might be advantageous to detect the start bit of a UART transmission in certain cases.
If you have defined UART baudrate then you may configure UART for reception and then just wait till RI flag has been set -- if its interrupt is disabled then you "win" control over the flag. In this case you need not with changing of UART interrupt subroutine vector - just disable it. Can I just poll the appropriate port pin P3.0/Rx, even while the UART is enabled ?
Polling of UART Rx pin is not a good idea generally. You see, internal hardware has a "feature" to detect true bit stream state called "bit detector". In short, it checks the Rx pin three times in middle of each bit (divided by 16 time slots internally) to detect true state of it. Read more in UART hardware description manual. In some conditions it may not be possible to do the same way by software. Regards, Oleg |
| Topic | Author | Date |
| UART start bit detection? | 01/01/70 00:00 | |
| Bible time... | 01/01/70 00:00 | |
| there is no answer | 01/01/70 00:00 | |
| It's an Analog Devices ADuC845. | 01/01/70 00:00 | |
| HUH | 01/01/70 00:00 | |
| It's being updated | 01/01/70 00:00 | |
| what is an IVT? | 01/01/70 00:00 | |
| Interrupt Vector Table | 01/01/70 00:00 | |
| i do not know your device but .. | 01/01/70 00:00 | |
| what do you try to do | 01/01/70 00:00 | |
| poll RI | 01/01/70 00:00 | |
| if he is working with 'collisions' he can not | 01/01/70 00:00 | |
| That would be too simple. | 01/01/70 00:00 | |
| clairvoyant chips? | 01/01/70 00:00 | |
| Not necessarily | 01/01/70 00:00 | |
Oh I see. Stupid me. Thanks. | 01/01/70 00:00 |