storing data at 100Mhz - Page 1
Forum section: electronics / beginners

author: abhimanyu
author_rank: Newbie
timestamp: September 12, 2010, 09:58:22 am
content: hii want to store 10byte parallel data being recieved at a speed of 100Mhzprecisely speaking the data is valid for 6ns and then for the next 4ns it settles to the next valuethe total data will be about 200Kbytesafter 200KB is filled this data is to be send to the computer ( till the data is send to computer no new data comes in )i have been looking for ram, counters, cpld, but could not figure put how to achieve this efficiently by spending not more than 40$

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: September 12, 2010, 10:15:52 am
content: Ok, so you need an data logger for less than 40$ , it will not happen in this life .. sorry .

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 12, 2010, 11:33:01 am
content: A small FPGA or CPLD and some fast external SRAM would do this easily, and less than $40 in part, but not once you've put it on a PCB.Do you mean 10 bytes or 10 bits? 10 bytes is doable but you'd have a very wide bus, and will be well out of your price targetMany FPGA devboards have SRAM, but you'll have to pay a little more. You will probably struggle to find a board with fast enough SRAM, but slower, wider RAM is another option.Probably the cheapest would be to use a reasonably wide SDRAM with a FIFO in the FPGA to cover the setup periods.For PC download something with onboard USB, would be useful to make a single-board ready made solution - I'm sure there is something out there, but not for $40.This productmight be an option. There are plenty more out there.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 12, 2010, 01:07:42 pm
content: Some common (and very cheap if you know where to get it) PC133 will do that nicely.

author: Unknown
author_rank: Unknown
timestamp: September 12, 2010, 01:21:49 pm
content: Getting the data in there will probably be not so cheap.

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 12, 2010, 07:50:39 pm
content: 10 bytes x 100MHz = 1GB/s? to computer? jeez! i have Arduino data logger for around $40 allright! but not at this 1GB/s!

author: Simon
author_rank: Unknown
timestamp: September 13, 2010, 06:57:06 am
content: Quote from: shafri on September 12, 2010, 07:50:39 pmNo I think he wants to acquire at 100MHz and then send a block of 200KB to a computer, basically he wants a buffer to take a shot of 200KB at 100MHz and then send it on in it's own time before acquiring more

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 13, 2010, 11:36:22 am
content: oo ok. but still 1GB/s to RAM during less than 200KB is achieved. still quite almighty. maybe parallel RAM will do the trick. never look into the detail of RAMing though.

author: Unknown
author_rank: Unknown
timestamp: September 13, 2010, 11:50:26 am
content: He basically needs a fast FIFO, but I think 80 * 2500 at 100MHz is pretty expensive (IDT72V3660L6PFG, 4Kx36 166MHz FIFOis about $50 each, and you'd need three for 80 bits wide). But you'd need an FPGA for external SDRAM, which is expensive, too.My guess is that you won't get a solution for under $40 unless you either change the specs or the budget, unless you can reuse some existing equipment that you can get cheaply.

author: abhimanyu
author_rank: Newbie
timestamp: September 13, 2010, 04:12:35 pm
content: okkso let me think on my design and budget once againi will be back once i am done with the changes in the design to reduce data rate or to increase my budgetthanks you everyone for your inputs