how to read data from inout port into a testbench

Altera_Forum · ‎11-06-2015

Hi, I'm writing a test bench to write data into an sram module. I have to write the data and read back from it. data is inout port in that module. How do I read the data back from the module into my test bench? This is my code...

`timescale 1 ns/10 ps

module ht6116_tb();

reg [7:0] data_set;

wire [7:0] data;

reg [10:0] address;

reg write_enable_n, read_enable_n, chip_select_n, reset;

IDT6116SA15 M1(.IO(data), .A(address), .WE_N(write_enable_n), .OE_N(read_enable_n), .CS_N(chip_select_n), .RESET(reset));

assign data = data_set;

initial

begin

reset = 1'b0;

address = 11'h0;

write_enable_n = 1'h1;

read_enable_n = 1'h1;

chip_select_n = 1'h0;

# 100;

data_set = 8'h55;

write_enable_n = 1'h0;# 100;

write_enable_n = 1'h1;

data_set = 8'hzz;# 100;

read_enable_n = 1'h0;

# 100;

end

Altera_Forum · ‎11-09-2015

`timescale 1 ns/10 ps module ht6116_tb(); reg data_set; reg read_data; // Somewhere to store the data in your test bench wire data; reg address; reg write_enable_n, read_enable_n, chip_select_n, reset; IDT6116SA15 M1(.IO(data), .A(address), .WE_N(write_enable_n), .OE_N(read_enable_n), .CS_N(chip_select_n), .RESET(reset)); assign data = data_set; initial begin reset = 1'b0; address = 11'h0; write_enable_n = 1'h1; read_enable_n = 1'h1; chip_select_n = 1'h0; read_data = 8'h00; // You might want to provision your reg but you don't have to. # 100; data_set = 8'h55; write_enable_n = 1'h0; # 100; write_enable_n = 1'h1; data_set = 8'hzz; # 100; read_enable_n = 1'h0; # 50; read_data = data; // Read the data in (e.g. half way through your read enable pulse, but can be anywhere whilst read enable is active) # 50; read_enable_n = 1'h1; # 100; end

Cheers,

Alex

Altera_Forum · ‎11-10-2015

Well you could create a bidir controller. Search this forum for bidir (short for bidirectional) and you will find some references. You can also directly write Z when you read and write the value when you write.

Altera_Forum · ‎11-11-2015

Hey Thanks!!