On Thu, Sep 29, 2011 at 12:48 PM, Mark Rages wrote: > On Thu, Sep 29, 2011 at 10:29 AM, wrote: > > > > I built a logic analyzer many years ago that used an oscillator that > > would increment the address counter > > of some dual port cache RAMS. You could capture using one port of the > > ram chip, and output the data on the > > other port. The dual port rams were from Cypress IIRC, and I believe > > they were 128K x 9. I used the 9th > > bit as a trigger capture bit. After the capture, I would then send the > > captured data out to the PC for > > display. It worked well. You might try looking at some of these RAM > > chips. Again, IIRC, they would work > > up to about 60 Mhz or so. > > > > Microchip has some serial RAMs that do this. Just keep clocking them > and they store a bit with each clock. Design here: > http://dangerousprototypes.com/docs/Logic_Shrimp_design_overview > > The only problem I have with these is that 256K samples isn't enough. I can store 250k samples on the PIC32 RAM itself if I wanted to. I either need to stream it to the host on the fly, or need some cheap DRAMs. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .