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Altera_Forum
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12 years ago

Cyclone IV total embedded memory size

Hi,

i am quite new to FPGA programming,

and a bit confused about the range for on-chip memory.

In my project i am using an Cyclone IV EP4CE10E22C8N board.

I would like to know now how much memory i can assign in Qsys to my on-chip RAM module.

The total memory size must be less tha the available in the target FPGA.

From the cyclone IV dev handbook i know that the FPGA i use has 414 Kb

organized in M9K memory blocks (so i have 46 M9K blocks)

So i should be able to use slightly less for my RAM if the cpu takes some memory for itself as i read in

http://www.alteraforum.com/forum/showthread.php?t=39788

In qsys my nios processor uses tweo m9k blocks. So i should be able to set up a system with about 45 KB. But compiling

in Quartus i get the error message,

that my design does not fit into the device, so i'm not sure how to calc the max usable memory size.

Also i stumbled over the Mega Wizard Plugin Manager where i can setup my own blocks in quartus.

When i want to create a RAM device there and increase the amount of 32 -bit words (as my nios cpu has a 32 bit data bus) i monitor that the resource usage contains for example 34 luts; 64 M9K blocks and 2 register.

Now i dont really understand how many M9K blocks are there on the FPGA?

Thanks a lot in advance for your answers!

Cheers

Tim
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