Passing a hexadecimal value into a module in Verilog

Verilog treats all bare numeric literals as decimal. A and D are not legal decimal values. For hexadecimal literals, you need to specify the literal type using ‘h: Refer to the IEEE Std (1800-2009, for example), section “Numbers”. The following code compiles for me without errors on 2 different simulators (Incisive and VCS):

Verilog Testbench Clock

Try moving clk=0 above the forever loop. Instead of toggling the clock every #10 you’re resetting the clock to 0 every #10 units, and then toggling it instantly. I think that still might work in some cases, but it’s probably not what you intended to do.

What is the difference between reg and wire in a verilog module

Wire:- Wires are used for connecting different elements. They can be treated as physical wires. They can be read or assigned. No values get stored in them. They need to be driven by either continuous assign statement or from a port of a module. Reg:- Contrary to their name, regs don’t necessarily correspond to physical … Read more

Difference between “parameter” and “localparam”

Generally, the idea behind the localparam (added to the Verilog-2001 standard) is to protect value of localparam from accidental or incorrect redefinition by an end-user (unlike a parameter value, this value can’t be modified by parameter redefinition or by a defparam statement). Based on IEEE 1364-2005 (ch. 4.10.2): Verilog HDL local parameters are identical to … Read more

Priority encoder in verilog

I am somewhat new to verilog, I tried running this code but it gives me an error: I think it complains about in[7:i+1] but i don’t understand why ? Can someone please advise.. EDIT ok so I am reluctant to using the X due to their numerous problems.. I was thinking of modifying the code … Read more

XOR signal in verilog

There are a couple of ways of doing this. One way could be to build a 4-input XOR module, and then instantiate multiple copies. Another way would be to use a for-loop. This won’t work with all the cases, since you don’t have an evenly-divisible number of wires. There are some other tricks (like 0-padding … Read more