#Verilog modelsim software#
#Verilog modelsim code#

The access routine acc_initialize initializes the environment for access routines and must be called from your C-language application program before the program invokes any other access routines.

In our case we need to include the acc routines include files. As for any another C code, we need to include the header files specific for the application that we are developing.

#Verilog modelsim code#

Let's look at the code below, before we go into details.Д¬ounter_monitor is our C function, which will be called from the Verilog Testbench.

Predefined VCL flags: vcl_verilog_logic for logic monitoring vcl_verilog_strength for strength monitoringДЄcc_vcl_add(net, display_net, netname, vcl_verilog_logic).

String to be passed to the consumer C routine.

Consumer C routine to call when the object value changes.

Use acc_vcl_add routine, whose syntax can be found in Verilog PLI LRM.ДЄcc_vcl_add routine basically allows us to monitor a list of signals, and whenever any of the monitor signals change, it calls the user defined function (called Consumer C routine).

This can be achieved by using the routine below. (Note: By the way, it's normally a good idea to drive reset and clock from Verilog code.) Whenever the clock changes, the counter function needs to be executed. Writing a counter in C is so cool, but when do we increment the counter value? Well we need to monitor the change in the clock signal.

Terminates the simulation, whenever the checker fails.

We will call our PLI function as $counter_monitor. Let's define the requirements for our infamous counter testbench using PLI. There is a set of routines (functions) that Verilog PLI provides which satisfy the above requirements.

Means to drive any signal value inside Verilog code from C code.

Means to get the changing signals (or any other signal) value in Verilog code into the C code.

Means to call the C model, whenever there is a change in input signals (Could be wire or reg or types).

First let's list out the requirements for writing a C model using PLI. Let's consider our infamous counter example and write the DUT reference model and Checker in C and link that to the Verilog Testbench. Example in IEEE Std 1800-2012 В§ 23.The example that we saw was too basic and is no good for any practical purpose. It is legal to define parameters and localparams after the header with with ANSI style headers so long as the header does not references them. Anything that supports that syntax would be from outside the standard. There is no mentioning of a header syntax matching: module_name ( port_direction_and_type_list ) Д«ased on the LRM, your sample header is non complaint. The informal general syntax of an ANSI style module header is as follows: module_name #( parameter_port_list ) The ANSI header style makes the declarations of the port characteristics part of the module header (which is still terminated by a semicolon). Declarations that define the characteristics of the ports (direction, size, data type, signedness, etc.) The module header definition is syntactically completed by the semicolon after the closing parenthesis of the port list. The informal syntax of a non-ANSI style module header is as follows: module_name ( port_list ) The non-ANSI header style separates the definition of the module header from the declarations of the module ports and internal data. There are two styles of module header definitions, the non-ANSI header and the ANSI header. IEEE Std 1800-2012 В§ 23.2.1 Module header definition state two header types: The other way is also to use the following construct: module module_name #(parameter w1 = 16, parameter w2 = 8)(Д«ut: is it illegal (Quartus suggests it's not) to define parameters after input/output signals that uses this parameters? I found the way to bypass this issue with following code: module module_name( Identifier must be declared with a port mode: in2

Identifier must be declared with a port mode: in1 (vlog-2388) 'in1' already declared in this scope (module_name) But, when I tried to simulate that code in Modelsim(-Altera) 10.3d, I got following errors:

#Verilog modelsim software#

Recently I've came across following issue: in Quartus software I've defined my Verilog module as follows: module module_name(