| ??? 10/12/06 19:46 Modified: 10/12/06 19:49 Read: times |
#126340 - in the prototype area or ... Responding to: ???'s previous message |
Erik Malund said:
Richard Erlacher said:
We've already established that the 8-port MCU won't fit in the application board. I have no such knowledge. If an 8 port MCU will not fit where is the room for the 'expansion' chips? in the 8255 socket! If the MCU isn't in DIP-40 or PLCC-44, it probably won't fit on most commercial boards that a newbie's likely to have. I've yet to see an 8-port MCU that fits in either of those. Erik Malund said:
Richard Erlacher said:
Parallel latches, well, they'll obviously work if one uses an external memory bus. You've pointed out, however, that you don't like discarding two ports, so that only applies if the external bus is already present. Of course, that should be self-evident. The issue here is that it will be extremely rare that you need parallel expansion unless you have already applied external memory. I think you're assuming facts not in evidence. Plenty of times, I've found that the PLCC-44 on the board I'm using doesn't have enought I/O's, and/or the port they're on is inconvenient to use for firmware timing reasons. That says nothing about whether one's using internal or external code space. Code space has seldom been a issue for me. It's the data space I seem to need more and more. Erik Malund said:
Richard Erlacher said:
The "WSI" chip you keep mentioning. You mean the ST (u)PSD813-series? Which one? Please be specific. Remember, WSI doesn't exist any longer. What do they cost? I can't find any of them for sale anywhere.
FOR THE LAST TIME I included the PSD chips (which I have used in the distant past) for the sake of making a complete list not to be dragged into performing a web search. Jan, can you (who evidently use the flash based psd chips) answer these questions, just to shut Richard up, Yes, I'd appreciate that. I've found reference on ST's site to about 20 of these parts that are discontinued and only four that are still apparently in production, though two of them are 3-volt parts, so only two work with a given supply. Nobody's asking you to performa a web search. I'm just asking you to stop with the hand-waving and be specific as to which device it is that you mean, so a newbie can pick up the thread. I'd certainly be interested in letting people know what these guys cost just to see how they fit into the greater scheme of things. RE |
