how to read an csv file in verilog code

[jean]

hello everyone, i will need help. I would like to know if you have any idea how to store a ROM in fpga from an csv file. I have an CSV file contain hexadecimal data. I want to have a ROM in my design to read data from the external csv file. Thanks
 

[zygot]

Whenever you create a RAM or ROM using FPGA vendor's IP you are given the option of providing an initialization file. The vendor has it's own format such as MIF. Don't use a csv format use the vendor's format. Writing a small Python script or C program to automate the process of converting an array of data to the MIF format isn't very difficult.

[zygot]

Here's a snippet of my OCTAVE code used to create parts of the PhasorToy project that I posted in the Digilent Project Vault:

clc;
format long;
fixed_point_format(true);

# We want a sin lookup table covering 0 to (Pi/2) -1/(2^depth)-1)
bits  = 18;
depth = 2048;

rad_step  = pi/(2*depth)
deg_step = (rad_step/(pi/2))*90
max_rad = rad_step*(depth-1)
maxdeg = (max_rad/(pi/2))*90

for i=1:depth
  sintab(i) = sin(rad_step*(i-1));
  costab(i) = cos(rad_step*(i-1));
end

# Create a scaled std_logic .coe file
# Uncomment to write coe file
# A better to do this would be to save sintab to a file
# and write a separate function script to do the coe file writing....
S = floor(sintab*2^bits);
figure (3);
plot(S);
fid = fopen('sintab90.coe', 'w+');
fprintf(fid, 'memory_initialization_radix = 2;\n');
fprintf(fid, 'memory_initialization_vector = \n');
for i=1:depth-1
  fprintf(fid, dec2bin(S(i),bits));
  fprintf(fid, ',\n');
end
fprintf(fid, dec2bin(S(depth),bits));
fclose(fid);

Not all FPGA vendor data formats are suitable for simulation, so taking the time to learn how to insert data into your source code is well worth the effort.

 

[jean]

17 hours ago, zygot said:

Whenever you create a RAM or ROM using FPGA vendor's IP you are given the option of providing an initialization file. The vendor has it's own format such as MIF. Don't use a csv format use the vendor's format. Writing a small Python script or C program to automate the process of converting an array of data to the MIF format isn't very difficult.

thank you sir @zygot for your reply. I even tried to use a .mem or .text file containing hex data it works in the simulation without any problem . Unfortunately, after the synthesis and the generation of the bitstream, I wanted to do the debug to check its operation, a priori it does not read it or it had a problem. I am using  ZCU111 ultrascale

reg [15:0] ROM [0:4095];
reg [15:0] ROM2 [0:4095];
 
initial begin
$readmemh("I_data.mem", test_memory);
$readmemh("Q_data.mem", test_memory);
end
 

[zygot]

If there's a path from the ROMs in the PL to the PS via an AXI bus then you can read the ROM contents; otherwise you can't. Such a path is a waste of a lot of PL resources. If your ROMs were dual port ram then that's different. You'd have to have a good reason for expending PL resources for that kind of architecture.