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SS5
Novice
1,204 Views

Unable to read the data from AVALON FIFO MEMORY under on-chip memory

I want to write 32-bit data into FIFO and read that data from FIFO. [FIFO configuration :Aalon-MM write slave to Avalon-MM read slave.]

I have tried the below design but data is not in proper sequence.

Please anyone guide me.

 

Clock:50 Mhz

Design Flow as follows

Block design

Quartus

Block_quart.JPG

Qsys Design, FIFO_Block.JPG

NIOS console

Data is not in Proper sequence. I dont know where its going wrong ?

Nios.JPG

0 Kudos
7 Replies
KennyT_Intel
Moderator
120 Views

Hi,

 

You can try out the example here https://www.intel.co.jp/content/dam/altera-www/global/ja_JP/pdfs/literature/ug/ug_nios2_flash_progra... to see if you able read the correct memory.

 

Thanks​

Daixiwen
New Contributor I
120 Views

You write to the fifo faster than you read back from it, so you will miss a lot of the counter values. In your design the write signal is always 1, meaning you write a value on each clock cycle. On the other side, as you are using a CPU to read back the data, there will be multiple clock cycles between two reads.

SS5
Novice
120 Views

@Daixiwen. Thanks for your response. If you could tell me the solution to sort my problem means, it will be helpful to me.

 

Daixiwen
New Contributor I
120 Views

You can't write on each clock cycle. You should change your design to check whether the fifo is full or not and only write the value (and increment the counter) when the fifo is not full.

SS5
Novice
120 Views

>>You should change your design to check whether the fifo is full or not.

 

I am new to the Altera. So can you tell me how can the design should be modified, or else any design examples. Please guide me step by step.

 

Thanks.

SS5
Novice
120 Views

Thanks Daixiwen, I am able to print counter data in NIOS console.

SS5
Novice
120 Views

@Daixiwen. The above FIFO design is working. LIKEWISE, i have tried the same design.

Working Design BLOCK diagram block.JPG

In following design, i am generating Trigger signal (500ns) and Counter data using Verilog code. Then need to read the data in NIOS console using FIFO.

Code

module Counter( input clk, input enable, input reset, output reg[31:0] Final_value, output reg trig ); reg[31:0] counter_out; reg [7:0] temp; reg [31:0] counter_result; wire temp1; wire temp2; always@(posedge clk or negedge reset) begin if(~reset) begin trig<=0; temp<=0; counter_out<=0; end else if(enable==1'b1) begin counter_out<=counter_out+1; temp<=temp+1; if(temp==25) begin temp<=0; trig<=~trig; end end end assign temp1=trig; assign temp2=temp1&&clk; always@(posedge temp2 or negedge reset) if(~reset) counter_result<=0; else begin counter_result<=counter_result+1; end always@(posedge trig or negedge reset) if(~reset) Final_value<=0; else begin Final_value<=counter_result; end endmodule

FIFO DESIGN [NOT working]

Trig_FIFO.JPG

 

Can anyone point out me the error in my design. Please suggest me.

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