On 01/12/2011 10:01 PM, Brian Padalino wrote: > > Altera Cyclone IV EP4CGX15 FPGA, Analog Devices AD9861 MxFE, USB2 > microcontroller (for reprogramming the FPGA) in an ExpressCard/34 > format. The FPGA has a hard PCIe 1.1 x1 lane with a hard IP core for > PCIe connectivity. The PCIe interface has an extremely low latency > and pretty high throughput - ~200MB/sec full duplex (after overhead > and whatnot). The FPGA would be mostly empty since the PCIe core is > hard. If the F169 package is used, it should be compatible with up to > a EP4CGX30 which would give 80 18x18 multipliers and over 1Mbit of > embedded memory. The ExpressCard format can fit into desktop PC's > with simple and cheap adapters, or into laptops which have ExpressCard > slots. > > ExpressCard has both an x1 PCIe connection as well as a USB 2.0 > connection. I imagine a small USB 2.0 micro used for FPGA > configuration and, possibly, a secondary way for samples to enter/exit > the FPGA for different use cases (similar to the original USRP). But > the main purpose would be for reconfiguration of the FPGA. > > Frequency synthesis can be an optional part of the assembly. I > imagine a relatively inexpensive VCTCXO (2ppm accuracy?) along with an > Si5338 clock synthesis chip. The idea, though, is to be completely > optional for those who really want it. Otherwise, the FPGA PLL's can > probably be good enough for most people. > > > There are a couple of downsides to a PCIe implementation that I can think of:
o not all host platforms are going to have PCIe slots o it's noisy in there! The upside, as you point out, is that it'd be high bandwidth into the host. -- Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
