Good day to all. I'm tackling another project where I need to intercept a SPI data=20 stream and modify the data on the fly. I'm only interested in=20 modifying the data feeding a pair of 74hc595 shift registers but the=20 SPI buss is used for talking to lots of different devices. There is=20 a separate Latch line that latches the data into the two shift=20 registers at the appropriate time. So: I have to continually buffer two bytes worth of data until the=20 Latch line becomes asserted. I'll then modify the data and spit it=20 out to the shift registers. I haven't even put a scope on this beast yet to see how fast the SPI=20 data is but I suspect that its pretty quick - there are a lot of=20 devices on the buss that are updated in real time. Although my first thought was to use a PIC that can do hardware SPI=20 slave, I'm not sure if its fast enough. I'll find out later today=20 when I put a scope on the SPI buss. Assuming that the PIC isn't fast enough, my next thought was to use a=20 small CPLD. Therein lies my problem. All of my CPLD experience is with old Intel / Altera parts: ep320,=20 ep610, ep910, epm7032, epm7128. The last of those projects was=20 around 15 years ago and written in Altera's Advance Design File or=20 Text Design File formats (.ADF, .TDF). I have no experience with=20 Verilog or VHDL. That's the software side. The hardware side is also a little=20 challenging: the SPI buss and those shift registers are running from=20 5Vdc. Most modern CPLD's seem to be 3.3V or lower. So: I'm looking for suggestions for a small to medium size CPLD that=20 runs at 5V and has at least 40 macrocells. I can probably get away=20 with fewer macrocells (as few as 24) if I generate the output data on=20 the fly (rather than loading a 16-stage shift register and shifting=20 the data out) but I'd have to see how flexible the product term array=20 is for that kind of thing. I'd appreciate any suggestions or opinions that others might have. Many thanks! dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .