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De2-115 sram

Honored Contributor II

Hello, I'm having trouble with the university program SRAM core. There's only one option and that is to select the target board (DE2-115). However, when I go to run my C code it always tells me my processor is not responding. 


Because I'm simply just trying to get my SRAM to host my C code (so I can use the DRAM for other purposes) I only have a Nios CPU, switches, and the SRAM in my design.  


Does anyone know what could be going on or what I should do? Here's everything just for calcification. Also, the system is not accidentally left in a constant reset state; although that has happened to me before! 


/////////////////////////// VERILOG //////////////////////////////// 


module dram_system( 











input CLOCK_50; 

input [17:0] SW; 

inout [15:0] SRAM_DQ; 

output[19:0] SRAM_ADDR; 

output SRAM_CE_N; 

output SRAM_WE_N; 

output SRAM_OE_N; 

output SRAM_UB_N; 

output SRAM_LB_N; 


dramImageCPU dCPU ( 














///////////////////////////// NIOS ///////////////////////////// 

# include <iostream> 

using namespace std; 

int main (void) { 

cout << "Running..." << endl; 

return 0; 



-- Like I said, I just want it to run: 


bash-3.1$ nios2-download -g *.elf 

Using cable "USB-Blaster [USB-0]", device 1, instance 0x00 

Pausing target processor: not responding. 

Resetting and trying again: FAILED 

Leaving target processor paused 




I tried to make a custom SoPC module for the SRAM but I don't think I really know what I'm doing well enough for that, it didn't work. Now, this isn't really all that big a deal project wise since I'm just using the SDRAM controller for other portions but I do need the SRAM to work eventually so I'm open to ideas.  


Ideally, I would like to make my own core anyway but I don't really know how to do it. Thanks
0 Kudos
2 Replies
Honored Contributor II

My apologisies to Terasic and people interested: 

once i have lowered clock within access time of sram on the board everything was fine. Still can not explain why original Terasic design did not work. 

---below my original answer: ---- 

I am pretty sure that original IP from terasic “Terasic_sram “ has some problem. I had simple test writing and reading values from SRAM and it failed. Then I took one of the original sample design from de2-115 and tried to make simple “hello world”. It did load when code was in on chip or sdram. It did not load when i asked to download code to sram. In addition to this I have tried to run the same sram test (code in sdram) and it failed. My simple memory tests works nicely on all other boards. 

Zbigniew , sydney
Honored Contributor II



Could you please tell me your timing parameters. I could not get it working on DE2-115 with the following for the Terasic SRAM IP: 


Setup 0 

Read Wait 1 

Write Wait 0 

Hold 0 

Read Latency 0