| ??? 10/06/05 09:38 Read: times |
#102019 - why 8MHz? Responding to: ???'s previous message |
Sasha Jevtic said:
I said:
...consider using a different, more "standard" crystal value. The DS89C4x0 can go up to 33MHz, isn't it a pity to waste it's horsepower using low clock? Not necessarily. There is plenty of performance to be gained just dropping the '450 into a standard 8051-based circuit by virtue of it being a single clock device. At 33 MHz, you'll be hard pressed to meet the timing constraints of a lot of the peripherals you might want to use with it (at least without stretch cycles). Furthermore, the EMI issues you'll see at this speed, especially if you have external bus accesses, can be nontrivial. Certainly so. Nevertheless, even the "standard" 8051 is clocked at max.12MHz, that's 50% plus compared to 8MHz, so why waste it... ;-) No that was not really my point; I wanted to ask why Jeff cannot use a 11.0592MHz crystal... Jan Waclawek PS. Craig seems to be facing problems with the new server... Inserts slashes before each ' and "... |
| Topic | Author | Date |
| Other crystals? | 01/01/70 00:00 | |
| my experience | 01/01/70 00:00 | |
| dallas | 01/01/70 00:00 | |
| RTFM | 01/01/70 00:00 | |
| the speedy '450 | 01/01/70 00:00 | |
| why 8MHz? | 01/01/70 00:00 | |
| crystals | 01/01/70 00:00 | |
| '420 | 01/01/70 00:00 | |
| errata? | 01/01/70 00:00 | |
| 22.1184MHz | 01/01/70 00:00 | |
| since when? | 01/01/70 00:00 | |
| the tiny asterisk... | 01/01/70 00:00 | |
| Baud rates | 01/01/70 00:00 | |
| crystals, but problem fixed.... sorta :) | 01/01/70 00:00 | |
| 10472 baud | 01/01/70 00:00 | |
| but Atmel | 01/01/70 00:00 | |
| 8 bits autobaud | 01/01/70 00:00 | |
| explanation | 01/01/70 00:00 | |
| dallas | 01/01/70 00:00 | |
| 7.3728MHz | 01/01/70 00:00 | |
| Lower clock frquency | 01/01/70 00:00 | |
| backslashes | 01/01/70 00:00 | |
| New Server Problems? | 01/01/70 00:00 | |
| lol | 01/01/70 00:00 | |
| Go on laughing... | 01/01/70 00:00 | |
| rise/fall time? | 01/01/70 00:00 | |
| that is absolutely correct, but what mak | 01/01/70 00:00 | |
| jetplanes | 01/01/70 00:00 | |
| It's a combination of both | 01/01/70 00:00 | |
| thread | 01/01/70 00:00 | |
This is for the XA which has a UART that | 01/01/70 00:00 |