| ??? 12/17/04 19:33 Modified: 12/17/04 19:35 Read: times |
#83359 - happened here Responding to: ???'s previous message |
The design had not changed. The firmware had not changed. The board had not changed. The cables had not changed. They had changed nothing about this product, yet suddenly, with a newly produced batch of product and for no apparent reason, the product simply didn't work right any more.
The '51 manufacturer changed the chip mask, it still met the specs, but now at the min rise timings, where the old mask ran in the max rise timings. I had to analyze one of my predecessors design (which I was not at all familar with) to find out what the bug was. This is one of the reasons I preach "succesful testing does not prove theabscence of bugs, it proves the abscence of known bugs. An earlier experience was hardware where failings that were blamed on my software turned out to be that the hardware failed so rarely, that no one bothered about it, if the software was slow . It turned out that if the critical chip was Signetics, not TI the hardware worked because the chips had different delays (both within the specs). Erik |
| Topic | Author | Date |
| Weekend On-Topic (WOnT) | 01/01/70 00:00 | |
| microsoft ?? | 01/01/70 00:00 | |
| Cute ;) | 01/01/70 00:00 | |
| Weekend on Topic | 01/01/70 00:00 | |
| A very reasonable hypothesis | 01/01/70 00:00 | |
| happened here | 01/01/70 00:00 | |
| The chip changed | 01/01/70 00:00 | |
| What happened? | 01/01/70 00:00 | |
| Also an excellent hypothesis | 01/01/70 00:00 | |
| too much | 01/01/70 00:00 | |
| Nah. | 01/01/70 00:00 | |
| Me too, But | 01/01/70 00:00 | |
| systematic debugging | 01/01/70 00:00 | |
| Pb-free? | 01/01/70 00:00 | |
| Did the temp characteristics change? | 01/01/70 00:00 | |
| another one from memory | 01/01/70 00:00 | |
| What it's not. | 01/01/70 00:00 | |
| Solution | 01/01/70 00:00 | |
| Speed! | 01/01/70 00:00 | |
| Speed | 01/01/70 00:00 | |
| Would get the oscope, first | 01/01/70 00:00 | |
| Try this | 01/01/70 00:00 | |
| What it is? | 01/01/70 00:00 | |
| Think volume | 01/01/70 00:00 | |
| Not a puzzle!! | 01/01/70 00:00 | |
| Apologies | 01/01/70 00:00 | |
| Re: | 01/01/70 00:00 | |
| Y2K-and-something | 01/01/70 00:00 | |
| Y2K + something | 01/01/70 00:00 | |
| Y2k05 | 01/01/70 00:00 | |
| The Unix Epoch and the Year 2038 | 01/01/70 00:00 | |
| Yet another true story... | 01/01/70 00:00 | |
| A perfect example | 01/01/70 00:00 | |
| Newer IC | 01/01/70 00:00 | |
| Answer time...? | 01/01/70 00:00 | |
| another guess | 01/01/70 00:00 | |
| language | 01/01/70 00:00 | |
| Faster does not mean better! | 01/01/70 00:00 | |
| Ok | 01/01/70 00:00 | |
| Gladly | 01/01/70 00:00 | |
| To tell the whole truth... | 01/01/70 00:00 | |
| Hidden parameters | 01/01/70 00:00 | |
| Parasitic parameters | 01/01/70 00:00 | |
| Chip manufacturer changed? | 01/01/70 00:00 | |
| Faster/slower or "controlled" rise time | 01/01/70 00:00 | |
| Answer | 01/01/70 00:00 | |
| Amazing.... | 01/01/70 00:00 | |
| Amazed | 01/01/70 00:00 | |
| Split Planes | 01/01/70 00:00 | |
| A bit disappointed... | 01/01/70 00:00 | |
| Series resistors and line matching | 01/01/70 00:00 | |
| Series termination resistors | 01/01/70 00:00 | |
| Series termination | 01/01/70 00:00 | |
| SWR | 01/01/70 00:00 | |
| simulation to the rescue | 01/01/70 00:00 | |
| Thanks! | 01/01/70 00:00 | |
| The same moment? | 01/01/70 00:00 | |
| The same moment! | 01/01/70 00:00 | |
I'm Back. | 01/01/70 00:00 |