SDRAM：FLASH＝？

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originally posted by tommycp@Aug 19 2006, 02:09 AM

http://forum.niosforum.com/work2/style_emoticons/<#emo_dir#>/sad.gif

i am going to make a ep1c6q240 board.i want to get more adivce from you all.

this board is a test board,at last,i want to rum uclinux.if there is something wrong or not proper ,please give me some advice http://forum.niosforum.com/work2/style_emoticons/<#emo_dir#>/smile.gif .thank you a lot.

fpga:ep1c6q240c8

flash:4m=2m*16bit ........i don&#39;t know whether it is enough.

sdram:16m=4m*32bit ........i know sdram should bigger than flash,but sdram&#65306;flash&#65309;&#65311; is better?

sram:256k=64k*32bit

and something else like usb,net,key,led,lcd,uart,...........

thank you a lot with all my regards!!!!

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What&#39;s the end product? There isn&#39;t really any one right answer for memory choices.

Flash: Non-volatile storage of software and optionally hardware. What&#39;s the ratio?... depends on how many software+hardware images you want to store.

SDRAM: I&#39;d recommend DDR due to the industry shift. How much? Depends on your code needs. If you will have multiple software images then SDRAM may be smaller than Flash.

SRAM: I&#39;d recommend SSRAM if you need fixed (and low) latency performance. If you are targetting low power then I would look at the data sheets since SRAM devices use much more power per memory cell than SDRAM. Plus SRAM devices cost more per memory cell as well.

If you are not sure still what you need, I recommend building up a system in SOPC Builder with some RAM that you intend to use and building some software to get a feel for what you really need. Also most importantly when you go to layout the board route extra signals in case you need to go to a higher memory density using the same package (extra address lines).

BadOmen

Thank you very much.I think I get what I want