| ??? 02/12/07 01:42 Modified: 02/12/07 01:58 Read: times |
#132571 - Please quote carefully... Responding to: ???'s previous message |
Jan said:
However, there is a section of an internal POR, which obviously doesn't work (and the proof is that they cannot properly document it). It explicitly says, "no need for external reset any more"... Please quote carefully what they actually wrote: Atmel said:
"A 1msec internal reset signal will generated after power-on, eliminating the need for any external Power-on reset circuitry." Jan said:
Also, no mention on higher power spikes sensitivity. Look at the Philips' P89C51RD2->P89V51RD2 migration document - they frankly admit the 'V needs finer power. They actually state: Philips said:
Old applications with minimum decoupling might need an update for migration to the 89V51RX2. I cannot see, that the 'V'-series "needs" finer power. Also, a good designer always provides a certain headroom and does not apply minimum decoupling. Again, Daniel had non-tolerable noise on Vcc and possibly an improper design. So, if the AT89S8253 isn't working properly with that huge noise, this is not neccessarily indicating, that the micro has a "bug" and is unacceptably susceptible to noise on Vcc, but can also simply demonstrate a design mistake. Jan, we know nothing about Daniel's setup. And when then a failure occurs and Daniel reports on a "bug", we should carefully look at his setup, and not instantly shout "this micro is crap"! I can show you dozens of improper designs, which work properly with 74HCMOS but immediately fail with 74FAST-TTL or 74ACMOS. Would you instantly accuse the manufacturer of the latter chips to manufacture crap? I would you ask: "Hey man, do you use a multilayer board?" But with Daniel it's clear for you, that the AT89S8253 has a bug, and this without any analysis... Kai |
