| ??? 07/15/05 19:38 Read: times |
#97454 - And it supports DS89C4x0! Responding to: ???'s previous message |
Craig,
I was just taking a look at the SBC; it looks very nice. I thought it was quite a nice touch that you've added support for the DS89C420 (presumably it works with the '430, '440, and '450 as well, recent revisions of which seems to have less errata than the '420). I don't know what your intentions are about people being able to use higher frequency oscillators, but I wanted to point you in the direction of an application note from Dallas in case you haven't already seen it: Microcontroller Design Guidelines for Reducing ALE Signal Noise. I suspect this might not be an issue at under 12 MHz, but at higher frequencies, it certainly can be. I just had a run-in with this situation recently; I was doing external memory pattern tests on a DS89C450 @ 29.4910 MHz, and ALE noise prevented successful completion of the tests. It was something of a Heisenbug; simple application of the scope probe was enough to resolve the issue, and it couldn't be seen on the scope. Although frustrating, Kevin at Dallas pointed me in the direction of this app note; a small capacitor from ALE to ground was all that was required. --Sasha Jevtic |
| Topic | Author | Date |
| 8052.com SBC | 01/01/70 00:00 | |
| SBC | 01/01/70 00:00 | |
| I'm Interested, but no big hurry | 01/01/70 00:00 | |
| Good point | 01/01/70 00:00 | |
| BTW | 01/01/70 00:00 | |
| I'll update | 01/01/70 00:00 | |
| This is a nice chip when you need pins g | 01/01/70 00:00 | |
| Questioins | 01/01/70 00:00 | |
| elaborations | 01/01/70 00:00 | |
| RD2 programming | 01/01/70 00:00 | |
| Question | 01/01/70 00:00 | |
| RD2 and PSEN | 01/01/70 00:00 | |
| LeDot | 01/01/70 00:00 | |
| solder point | 01/01/70 00:00 | |
| go figure | 01/01/70 00:00 | |
| solder point/LeDot | 01/01/70 00:00 | |
| Jumper/button | 01/01/70 00:00 | |
| datasheet | 01/01/70 00:00 | |
| RD2, /PSEN and the joy of being perfect | 01/01/70 00:00 | |
| I think | 01/01/70 00:00 | |
| Herr Ohm says no | 01/01/70 00:00 | |
| Hands off | 01/01/70 00:00 | |
| no touch | 01/01/70 00:00 | |
| tidbits | 01/01/70 00:00 | |
| AT89S8253 | 01/01/70 00:00 | |
| First hand experiance | 01/01/70 00:00 | |
| RE:Experience | 01/01/70 00:00 | |
| SBC page updated | 01/01/70 00:00 | |
| Required HW for 8052.com Institute of uC | 01/01/70 00:00 | |
| that Erik has voluteered to teach ??? | 01/01/70 00:00 | |
| Retirement | 01/01/70 00:00 | |
| Well | 01/01/70 00:00 | |
| genetically as well | 01/01/70 00:00 | |
| I too... | 01/01/70 00:00 | |
| u51 one possibility | 01/01/70 00:00 | |
| I like part of that | 01/01/70 00:00 | |
| not good | 01/01/70 00:00 | |
| I see your point - did you see mine? | 01/01/70 00:00 | |
| got better | 01/01/70 00:00 | |
| you did not | 01/01/70 00:00 | |
| Are you sure about your .29$ | 01/01/70 00:00 | |
| oops | 01/01/70 00:00 | |
| single nand gate?? | 01/01/70 00:00 | |
| Ok spelling it out | 01/01/70 00:00 | |
| And it supports DS89C4x0! | 01/01/70 00:00 | |
| Nice effort | 01/01/70 00:00 | |
| PCB layouts | 01/01/70 00:00 | |
| not even gerber? | 01/01/70 00:00 | |
| ExpressPCB | 01/01/70 00:00 | |
| Keil was | 01/01/70 00:00 | |
| If needs be | 01/01/70 00:00 | |
| 8052.com SBC available for ordering | 01/01/70 00:00 | |
| Selling like hotcakes? | 01/01/70 00:00 | |
| Not bad | 01/01/70 00:00 | |
| AT89S8253 | 01/01/70 00:00 | |
| Yes | 01/01/70 00:00 | |
| Errata | 01/01/70 00:00 | |
| AT89S8253 ISP | 01/01/70 00:00 | |
| Didn't look very hard | 01/01/70 00:00 | |
| I already tried | 01/01/70 00:00 | |
| 8052.com SBC and 8052Sim | 01/01/70 00:00 | |
| Sort of and yes | 01/01/70 00:00 | |
| Pinnacle52 | 01/01/70 00:00 | |
| Why? | 01/01/70 00:00 | |
| Touche' | 01/01/70 00:00 | |
| Hard to resist | 01/01/70 00:00 | |
| Dress | 01/01/70 00:00 | |
| re classes etc | 01/01/70 00:00 | |
| re classes etc - an example | 01/01/70 00:00 | |
| Question on BOM | 01/01/70 00:00 | |
| Yes | 01/01/70 00:00 | |
| New Items added to 8052.com SBC Page | 01/01/70 00:00 | |
| 74LS573? | 01/01/70 00:00 | |
| Correct | 01/01/70 00:00 | |
| reset | 01/01/70 00:00 | |
| Errata | 01/01/70 00:00 | |
| Mine has arrived . . . | 01/01/70 00:00 | |
| Wow | 01/01/70 00:00 | |
| A minor problem | 01/01/70 00:00 | |
| Caps for MAX232 | 01/01/70 00:00 | |
| Whole point.... | 01/01/70 00:00 | |
| MAX232 Caps | 01/01/70 00:00 | |
| Deflux | 01/01/70 00:00 | |
| Works like a charm! | 01/01/70 00:00 | |
| Never mind, got it figured out | 01/01/70 00:00 | |
| Glad you got it working | 01/01/70 00:00 | |
| SBC-BASIC | 01/01/70 00:00 | |
| See email | 01/01/70 00:00 | |
| yes I will... | 01/01/70 00:00 | |
| Any luck with that yet? | 01/01/70 00:00 | |
| Not yet | 01/01/70 00:00 | |
| Sure! | 01/01/70 00:00 | |
| in that case... | 01/01/70 00:00 | |
| I've got a couple of RD2's | 01/01/70 00:00 | |
| http://www.efton.sk | 01/01/70 00:00 | |
| What about ED2's | 01/01/70 00:00 | |
| yes | 01/01/70 00:00 | |
| Basic 52/RD2 | 01/01/70 00:00 | |
| b52rd2 | 01/01/70 00:00 | |
| it works for me | 01/01/70 00:00 | |
| Real hackers | 01/01/70 00:00 | |
Basic 52 | 01/01/70 00:00 | |
| I got mine today! | 01/01/70 00:00 | |
| Darn the luck | 01/01/70 00:00 | |
| Comments | 01/01/70 00:00 | |
| Our Radio Shack Stinks | 01/01/70 00:00 | |
| An Idea | 01/01/70 00:00 | |
| 125 | 01/01/70 00:00 | |
| RE: '125 and JP4 | 01/01/70 00:00 | |
| Yes position? | 01/01/70 00:00 | |
| Got it - Bad 8253 | 01/01/70 00:00 | |
| No explanation | 01/01/70 00:00 | |
| You were right the first time - my bad | 01/01/70 00:00 | |
| No problem | 01/01/70 00:00 | |
| Memory mapped LCD problems | 01/01/70 00:00 | |
| Hmmm | 01/01/70 00:00 | |
| Building one | 01/01/70 00:00 | |
| Microseconds? | 01/01/70 00:00 | |
| Scale error | 01/01/70 00:00 | |
| Memory-mapped LCD initialization | 01/01/70 00:00 | |
| Thanks, Craig! It works! | 01/01/70 00:00 | |
| SBC - Manual | 01/01/70 00:00 | |
| SBC document | 01/01/70 00:00 |