Re: Memory Initialization File for multiple RAMs

Altera_Forum · ‎02-02-2010

Hi,

I'm new to FPGA development and maybe this question is simple, but I couldn't find an answer yet.

I am developing a system with multiple M4K memories which are instatiated inside a generate block over a genvar loop (I'm using Verilog and a Stratix II). For simulation I need them to be initialized with different data. I can specifiy a Memory Initialization File in the MegaWizard but this will initialize all memories with the same data. Is there an easy way to specify a different .mif for each memory?

Altera_Forum · ‎02-03-2010

yes, slightly edit the generated file, and add a parameter to it.

Then assign a different string to that parameter each time you instanciate it in the for loop.

Altera_Forum · ‎02-03-2010

Thanks amilcar, how do I assign the parameter within the code?

Altera_Forum · ‎02-03-2010

after the memory instantiation add:

defparam ram_inst.altsyncram_component.init_file = "your_file_here.mif";

Altera_Forum · ‎02-04-2010

Ok I got it so far. I am using the M4K memory within an other design unit. Here is the simplified code:

module LocalMem(...);
parameter cpuid = 0;
M4K memory (
    .clock(clk),
    .data(m4k_data),
    .rdaddress(m4k_rdaddress),
    .wraddress(m4k_wraddress),
    .wren(m4k_wren),
    .q(m4k_q)
    );
defparam memory.altsyncram_component.init_file = {"mem", cpuid, ".mif"};
endmodule
module TestLocalMem(...);
LocalMem# (.cpuid(1)) localmem_inst(...);
endmodule

This does not work. Within the defparam line, cpuid seems to be empty. No matter what I set cpuid to, the file "mem.mif" gets loaded. I have also tried this to make cpuid the correct ASCII value:

defparam memory.altsyncram_component.init_file = {"mem", 8'd48 + cpuid, ".mif"};but no change...

Maybe you have another hint for me?

Altera_Forum · ‎02-08-2010

I found a solution :)

In case someone has the same problem here is my solution:

To have a parameter concatenated with a string, it needs to represent the number's ASCII value. Therefore 48 needs to be added to its value. An other thing has to be considered: all chars in a string are represented as 8-bit numbers, therefore the parameter has to be 8 bits wide:

parameter cpuid = 0;and

defparam memory.altsyncram_component.init_file = {"mem", 8'd48 + cpuid, ".mif"};fixed my problem :)