Memory Limitations of FPGA

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win2010

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Hi......................

I`ve files which are contain plenty addresses(integers 16-bit). Each file contain lakh together integers. I need to store and used in a program.
I`m worry about memory of FPGA whether which sufficient or not. Because each and every model has many memory blocks used i.e. RAM/ROM. After integrating all block there is no such issues which in large to store or like that. I used spartan 3A DSP.

What mearure should take before if it occure in future....?
 

I dont understand the question. FPGAs have lots of small memories. If you dont use them efficiently they get wasted. It is not like the memory on a PC.
 

I have lots of files to store then How effectively we can use the FPGA memory....I`m asking this
 

In verilog, you can use $readmemh:

initial $readmemh("pathtofile", memoryname);
Click to expand...

Please note that your file must be exactly on the same size of your memory. For example:

reg [31:0] RAM [0:511];
initial $readmemh("C:/RAM.dat", RAM);
Click to expand...

I use the file in HEX format, with the exact numbers of entries the memory needs. In example above, you would need a file with 512x32 bytes entries (e.g. FFFFFFFF). I am not sure if others formats are accepted, I always used like this.

Of course, you need a block inferred/explicit block RAM for this procedure. I have never tested this in distributed RAM.
 

win2010 said:
I have lots of files to store then How effectively we can use the FPGA memory....I`m asking this
Click to expand...

If you want to store lot data in to Spartan series FPGA it is not possible. Another way you can store data with your FPGA is using External memory Such us SRAM, DDR, Flash.

You can use IP core from Xilinx Patform Studio tool to interface with Memory to Processor and store data in it. program it to FPGA.

For that You require board similar to this with external memory

**broken link removed**

Regards,
Shahul
 

Thant you for replay.....

We have constraint on memory How can i come to know this much only FPGA going to store.....?
Is there any particular method to know....?
 

How can i come to know this much only FPGA going to store.....?
Click to expand...

By reading the FPGA's datasheet. Al lthe information about the FPGA is listed there.

r.b.
 

win2010 said:
Thant you for replay.....

We have constraint on memory How can i come to know this much only FPGA going to store.....?
Is there any particular method to know....?
Click to expand...

FPGA consist of 2 types of memory.
1.Block RAM
2.Distributed RAM

Check Datasheet for its size.
 

win2010 said:
Thant you for replay.....

We have constraint on memory How can i come to know this much only FPGA going to store.....?
Is there any particular method to know....?
Click to expand...


you can store the data in bram and reuse the bram multiple number of times...however in this case you cannot pipeline or do parallel processing...this may increase the delay of the algorithm so there is a trade off..
 

sreevenkjan said:
you can store the data in bram and reuse the bram multiple number of times...however in this case you cannot pipeline or do parallel processing...this may increase the delay of the algorithm so there is a trade off..
Click to expand...

Usually the higher latency means you get a higher data throughput. This is far more important for FPGAs.
 

sreevenkjan said:
if you are dealing with large chunks of source data latency is expected...
Click to expand...

This is rather vague, and doesnt really mean anything.
You may have a large dataset, but you may parrellise your algorithm to process it all in parrell. But this may not be possible. It depends on the data and situation.
 

you cannot store a data in parallel processing..in parallel processing once the data has been used up....when I say large chunks of data it definitely is not just a bit size data....of course it depends on the data and situation but like i said you have latency because its just not a bit size data..
 


What? I store plenty of data in my parrallel processing. Im usually processing pixels of data in real time video....
 

there is a reason why real time video is limited only to PC or large memory systems because machine learning algorithms need video data samples which helps in the classification process so fpga is not suited for such kinda algo's
 

Are you joking? There are plenty of people doing real time video processing on video with very small FPGAs. A 2d FIR can be done on real time video with 2 line latency for example inside an FPGA. It can be done on an FPGA costing about less than $100.

How do you think TV companies compress their video streams for live transmission?
 

hi...2D FIR is a very basic algorithm and yes you do not need resuing bram or in fact u do not need bram...u just need a 2 line buffer like you have mentioned..but however requirement has been changed and people do much more complicated algo's than just the 2D FIR...by the way machine learning algo's are much more complex and they are database based...the algo which you are talking about is just a basic image processing algo..
 

Then why did you say real time video is limited to PC with large memory?

Yes, FPGA is not suited to all algorithms, but this thread isnt about that....
 

i never started the real video topic.you started it.you said you are processing real time video...what i was saying was that memory has a trade off and u need to have more than 100$ boards to process bigger memories and to try out fancy algo's than 2D FIR...
 


Well damn. I guess that means my non-database related multilayer perceptron doesn't work in this here spartan-6...
 

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