Timothy Miller wrote: > On 8/28/06, Peter TB Brett <[EMAIL PROTECTED]> wrote: > >> >> That was the general idea. I'd go for a PIC -- the 16F87 is one that >> supports >> both RS232 & SPI directly, for example. The advantage is, it's cheap and >> requires very few external components. > > SPI master? > > The one thing I don't see as having been addressed is that the SPI > clock rates we're using are like 20MHz and 33MHz. Can your embedded > processors push bits out serially at 33MHz?
Don't think so, even if the pre-engineered SPI port does the (de)serialization, the MCU itself can not prepare the data that quickly (I use Atmel's ATmega devices, not PIC or HCxx). But there is a solution, put one more chip (eeprom) into the "key" and make the whole device to behave as a prom emulator. When connected to OGA it "emulates" prom, when disconnected it's image can be changed over usb/serial. I hope it's still under $30 of dip switches/jumpers. I would prefer to use the DDC key - and when it supplies only ONE mode from EDID (detected by video-bios), the card's output will be set to that fixed mode. Daniel _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
