| ??? 07/05/07 00:38 Read: times |
#141502 - So it's ATMEL's fault? Responding to: ???'s previous message |
Jan Waclawek said:
Richard Erlacher said:
This particular circuit is one of a dozen or more very similar JTAG-capable programmers that I've seen. I've used similar circuits, both home-built and commercially manufactured, that program FPGA's and CPLD's. They've seldom been a problem of any sort. Why are these so difficult to use with ATMEL parts? Is it their (Atmel's) software? Is it the construction technique implemented by home-builders? YES! Plus, this is no JTAG (that's more complicated in protocol, hence slightly more error-resistant). But the AT89S' is SPI-ish. In case of the smallest crosstalk from any signal to clock, or "ringing" on clock, it gives up, or dies fatally rewriting the FLASH, depending on the circumstances. Although I don't doubt this for a moment, I wonder how you know it's the ringing on clock, or similar signal quality issues that are of concern. Some of the parallel-port JTAG adapters I have used over the years have been very "marginal" in their construction, inviting such problems, yet I've seen little evidence of this under JTAG. Since ATMEL uses JTAG names and typical circuitry, I'd believe that they now of and about JTAG. Couldn't they build similarly robust protocols with which to program their devices. Don't they know that it makes people less willing to use their hardware? LPT's have been standard and well-defined for decades. If they don't use it properly, it's because they don't want people to succeed in using their products. It's just another reason not to use ATMEL. Plus, you have the parasitic supply described oh so many times by Kai, troubles with improper power&reset sequencing (yes, Richard, reset, sounds familiar?) troubles with LPT not being standardised, modern PCs and OSs not liking LPT as a legacy stuff and doing funny things with it, problems with timing in modern OS... Chose your favourite.
JW |
| Topic | Author | Date |
| AT89 ISP | 01/01/70 00:00 | |
| alternative | 01/01/70 00:00 | |
| I found this in this forum | 01/01/70 00:00 | |
your link was helpful! | 01/01/70 00:00 | |
| Why do so many people "search" rather than "use" | 01/01/70 00:00 | |
| why does it fail | 01/01/70 00:00 | |
| So it's ATMEL's fault? | 01/01/70 00:00 | |
| it\'s not just Atmel | 01/01/70 00:00 | |
| Thank you.. | 01/01/70 00:00 | |
| few details required | 01/01/70 00:00 | |
| Either build and use what they recommend, or quit! | 01/01/70 00:00 | |
| and .. | 01/01/70 00:00 | |
| There\'s been a lot of discussion about this ... | 01/01/70 00:00 | |
| also | 01/01/70 00:00 | |
| Ok. Thank you. | 01/01/70 00:00 |