Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
7 years ago

Verilog Coding

Hello,

I'm getting the following error when I'm implementing the below Verilog code.

[Synth 8-403] loop limit (65536) exceeded

parameter N=10;

parameter M=8;

parameter depth=(1<<N);

reg [M-1:0]stack_mem[depth-1:0];

always@(posedge clk)

begin

if (rst==1'b1)

begin

next_sp=0;

dataout=0;

for(i=0;i<(depth-1);i=i+1)

begin

stack_mem[i]=0;

end

end

end

Here "For loop" has to increase only up to 1023 but again why I'm getting loop limit exceeded error?

Can anyone help me out?

Thanks in advance.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    7 years ago

    Where is i declared? Probably should be declared as an integer;

    Probably like this, with the added text in red: 

    always@(posedge clk)
    begin : block_name
    integer i;
    if (rst==1'b1)
        begin
        next_sp=0;
        dataout=0;
        for(i=0;i<(depth-1);i=i+1)
            begin
            stack_mem=0;
            end
        end
    end

    Note that by requiring that clearing the whole memory in one clock cycle be done, you will be forcing the implementation of stack_mem[] to be done be an array of clearable registers, and not using a block_ram type of memory structure. Hope that is what you intend.

    Also clk, rst, next_sp, and dataout need to be declared somewhere (maybe you left out some code ... ?)
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    7 years ago

    Thanks for your response. It's my mistake.i declared "i" as a single bit.