| ??? 04/04/05 21:55 Modified: 04/04/05 21:55 Read: times |
#91003 - baud rate errors/2 Responding to: ???'s previous message |
Andy Neil said:
Andy Neil said:
Note that Keil recommends a error of less that 1% in the actual baud rate:
http://www.keil.com/c51/baudrate.asp So, for a example, for a nominal 9600 baud, your actual value needs to be between 9504 and 9696. Sasha Jevtic said:
1% seems pretty conservative; some Dallas documentation states 3% tolerance Which Dallas doc was that? Did it justify this figure? Can you give a link? It is from the Ultra -High-Speed Microcontroller User's Guide. Specifically, the quote I mention is at the top of page 133, and is in reference to the autobaud detection scheme present in the ROM loader. It stops short of stating that 3% is the tolerance requirement for communication with the loader, but still seems to imply that. I can't justify the 1% - I just quoted it straight off that Keil page! I too am at a loss for where these numbers are coming from; I was just wondering why there seem to be so many different answers. That said, however, I certainly must agree with Erik's comment about the importance of avoiding these errors through proper oscillator selection in commercial products or other applications where compatibility/reliability of the serial interface is paramount. --Sasha Jevtic |
| Topic | Author | Date |
| Comm. Between 8052 & PC | 01/01/70 00:00 | |
| Whats the baud rate? Is it PC compatible | 01/01/70 00:00 | |
| Baud rate error | 01/01/70 00:00 | |
| baud rate tolerances | 01/01/70 00:00 | |
| some thoughts | 01/01/70 00:00 | |
| Baud rate errors | 01/01/70 00:00 | |
| baud rate errors/2 | 01/01/70 00:00 | |
| How about this? | 01/01/70 00:00 | |
| Serial Timing | 01/01/70 00:00 | |
| additional error | 01/01/70 00:00 | |
| plausible | 01/01/70 00:00 | |
| Oops! | 01/01/70 00:00 | |
| Cable? Speed? | 01/01/70 00:00 | |
| More on cables | 01/01/70 00:00 | |
Check cable pins | 01/01/70 00:00 | |
| PC Software? | 01/01/70 00:00 | |
| Really? | 01/01/70 00:00 | |
| Line termination: Some - not most | 01/01/70 00:00 | |
| Line termination | 01/01/70 00:00 | |
| GetLine ?! | 01/01/70 00:00 | |
| Exactly | 01/01/70 00:00 | |
| VB6 | 01/01/70 00:00 | |
| Some How!! | 01/01/70 00:00 | |
| another option | 01/01/70 00:00 | |
| Unspecific English | 01/01/70 00:00 | |
| Platform-Specific Line Termination | 01/01/70 00:00 | |
| Extra Line | 01/01/70 00:00 | |
| Lines, Platforms, and dead-end threads | 01/01/70 00:00 |