Am Samstag, den 22.10.2005, 10:54 +0200 schrieb Attila Kinali: > I would rather start from the other end: What for do we need > such a connector? If there is no need, do not put it in. > I know it would be cool to have one, to be able to extend > the board, to play with it. But keep in mind that everything > we add also adds cost in production. But such features > add very little value to the casual customer.
The freely usable I/O pins attached to a huge FPGA are the *ONLY* reason I'm following this project. > If you think we want one for future development and stuff > i would just connect the left over FPGA pins to a grid > of header pins. Though, you have to keep in mind that we > will be dealing with high frequency signals > (data clk freq*5 at least) and this will limit either > the use of the pins if we use cheap header pins or > we need to get an expensive connector with defined > wave resistance. The pins are not for future development. The pins are there to increase the potential market of the first cards from only OGP developers to anybody doing any kind of hardware development which could benefit from a relatively cheap evaluation board with a huge FPGA on it. E. g. universities. The most promising daughter board would be a simple buffer to get a TTL signal and drive LEDs, LCD displays, etc. with it. Therefore, there should be plenty of 3.3V and 5V power pins among (or besides) the data pins. A row with data pins and a parallel row with the sequence GND,3.3V,GND,5V comes to mind. Does PCI provide both voltages or only the one for which the card is designed? About the pins themselves: a grid of bare pins 0.1 inch apart seems to be the easiest to connect to. Make as many pins as will fit without affecting signal quality or bus widths elsewhere. If the pins cost too much, make only a few (if any) and leave the rest as pads with holes. - Viktor Pracht _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
