any example code for bidirectional port (inout)???

verilog bidirectional port

Is there any example of code to utilize a bidirectional port (inout)??? Maybe take for example, how to use it for a RAM with bidirectional data bus. Any other examples are welcomed as well. Thx

bidirectional port

hi,
below code may help you to understand bidirectional pins.

module top
(
input SysClk ,
input Sys_Rst,
inout I2c_Sda,
inout I2c_Scl
);

wire i2c_scl_out;
assign I2c_Scl = (i2c_scl_out == 1'b0) ? 1'b0 : 1'bz;
wire i2c_scl_in = I2c_Scl ;
wire i2c_sda_out;
assign I2c_Sda = (i2c_sda_out == 1'b0) ? 1'b0 : 1'bz;
wire i2c_sda_in = I2c_Sda ;

Instance Componant
(//==============================
// Globle Signals
.NSYSRESET ( sys_reset_n ), // input
.SYSCLK ( sys_clk ), // input
//-------------------------------------------
//==============================
// I2C Signals
.SDAI ( i2c_sda_in ), // input
.SCLI ( i2c_scl_in ), // input
.SDAO ( i2c_sda_out ), // output
.SCLO ( i2c_scl_out ) // output
//-------------------------------------------
);

endmodule

Hth

interface example +inout

can u explain what is performed by this statement?

assign I2c_Scl = (i2c_scl_out == 1'b0) ? 1'b0 : 1'bz;

Sorry because I only came across VHDL so far, I guess this is Verilog? Because this statement looks like something in C.

bidirectional port verilog

I know neither VHDL (am very slowly learning!) nor Verilog, but I know C/C++. In C/C++ the ? operator (called a ternary operator) works as follows:


So, using the line you showed, I2c_Scl will be assigned 1'b0 if the condition (i2c_scl_out == 1'b0) is true, otherwise it will be assigned 1'bz.

Hope this helps you.
TM

example bidirectional vhdl

Yes, Verilog syntax is near to C-language in many parts, here's the VHDL equivalent: