| ??? 08/20/06 05:52 Read: times |
#122648 - Small FPGAs Responding to: ???'s previous message |
Richard Erlacher said:
are there any current-generation FPGA's from brand X that you can program fully with a 1 Mb PROM?
IIRC, the 1 Mb part on one of my Insight EVB's for SPARTAN-II (XC2S100) FPGA's has a 1 Mb prom, and that's almost big enough. In order to FULLY utilize an XC2S200E, you need a 4 Mb part, though it's oversized. At their cost, however, you'd think they'd have produced a part that "fits" their FPGA. There's an XC3S50 which is probably the SMALLEST FPGA out there. Sometimes you just don't need a zillion gates. Lattice has small parts, too, but it's basically impossible to compare sizes. The problem with FPGA's, these days, is that if you want to use them to do useful work, you have to spend the money the mfg touts as your savings from earlier generations on bigger PROM's and then spend even more on level shifters. With 1.2 volts, it's hard to do anything. Try driving a power mosfet. Now consider that app that requires 136 of them. Oh, yeah, three friggin' voltages for some of the parts. That was another advantage the Lattice guy touted last time he came in ... the Lattice XP devices needed only one rail. And there's a part in a 100-pin TQFP! And Mouser has 'em, fifteen or twenty bucks in single-unit quanities and no config EPROM necessary. -a |
