req_cmd_ready()); I am guessing that mem_req_rdy is of pointer type svLogic* (since from the name of the function vc_putScalar, it seems that it intends to change the value held in mem_req_rdy). Here is an example. Syntax for looping through lower dimension of multidimensional associative array in a constraint. Also, we will see, PowerShell loop through an array using ForEach-Object loop, While loop, do-while loop, and do-until loop. Another "for" loop is used to iterate through each element of "C_Array" Class-Based SystemVerilog (Days 2 … to the class instance. The only thing you loose is x->z transitions. We have already discussed about dynamic array, which is useful for dealing with contiguous collection of variables whose number changes dynamically. So for example, any reg or wire in Verilog would be instantiated/mapped at the beginning of simulation and would remain... system-verilog,function-coverage,questasim, What you are asking for cannot be done, nor does it make any sense. Some simulators support evaluating function during compile/elaboration, but it doesn't appear to be a requirement. "for" loop is used to iterate through each element in the "R_Array". So when you... From your code snippet: xxx_model is a parameterized module that takes a parameter of type string named inst_name. How to loop through lower dimension in 2 dimensional associative array in a constraint? A double linked list is a chain of data structures called nodes. Associative array stores the data in the form of key and value pairs where the key can be an integer or string. For some reasons it works when I write the record elements in the lower case. The design may always have an even number of entries, but it looks like QuestaSIM's constraint solver is more pessimistic and and wants to consider all possibilities. So the associative arrays are mainly used to model the sparse memories. — webmaster@electroSofts.com. In this Names [i] + ': ' + DataField. foo.reg_fields.first( s ) ). I think you may be confused about why the events are printed multiple times? array, R_Array[i].C_Array[j] = new; // construct each You need to put your constraint in terms of a foreach loop. I'm posting this as an answer because I cannot put a photo in a comment. See https://verificationacademy.com/forums/coverage/how-get-values-different-bins-coverpoint. nam_dat Associative Array: Associative arrays are used to store key-value pairs. I played around with this a little bit and came up with an associative array of these types. If you can depend on the encoding, then you can define your collection with a wildcard and use the wildcard equality operator or inside operator let COMP_STATES = 3'b00? Wires can have multiple continuous drivers, and variables can have a single continuous driver, or multiple procedural assignment. Loop Through an Associative Array. vcover merge -testassociated This flag will keep an eye on each test's contribution to the coverage. Otherwise the loop can not determine how to how many times to loop for i. dynamic array of the class "ROW". Best way to check if variable is part of collection of enums? All of the builtin find_ methods require a with (expression). example shows how handles to class objects work. ValueFromIndex [i]); end; DataField. example demonstrates how to model a parameterized dynamic 2-dimensional $display("CELL[%0d][%0d] = %b %b %b",i, j. FR.R_Array[i].C_Array[j].A, FR.R_Array[i].C_Array[j].B,          constraint on those variables. array of classes. Arrays and Queues Dynamic Arrays • Queues • Working with Queues • Queue Methods • Associative Arrays • Associative Array Methods • Foreach. Properties can have local variables but the local variables cannot be defined inline with assert. SystemVerilog foreach specifies iteration over the elements of an array. The operator -> is used to... You need to use a local variable, see IEEE Std 1800-2012 § 16.10 Local variables Here is a simple example: property p_PropA; int count; @(posedge clk) ($rose(active),count=config) |-> (active,count--)[*] ##1 (~active && count==0); endproperty ... For most cases you can't beat the dedicated adder resources found in FPGAs. A foreach loop is only used to iterate over such arrays and is the Verilog arrays can only be referenced one element at a time. the class instance at that specific time. Finally, in the module "top", an instance of system-verilog,questasim. top level module then simply calls the built-in randomize function and It parses the key-value pairs of elements one-by-one and prints them in the output using the PHP echo function . In the above awk syntax: arrayname is the name of the array. When using a foreach on an double associative array, you need to include all the significant indexes. There are a couple of ways you could do this. In this tutorial, we will discuss how to loop through an array in PowerShell using for loop. The "FRAME" class also includes a You need to loop through the full slba_previous[id,i] and then check if id==nsid. First declare the Linked list type and then take instances of it. When the size of the collection is unknown or the data space is sparse, an associative array is a better option. dynamic array foo, if ( All variables in a task or function must be declared before any operation. In SystemVerilog, you can declare an explicit event and wait on that. As with There are several ways to loop over an array in JavaScript. Associative Arrays Example: This example shows the following System Verilog features: * Classes ... the "R_Array", each handle to the class instance needs to be constructed. The associative array contains elements in which all elements have a key that is manually assigned by the user. delete() removes the entry from specified index. "for" loop is used to iterate through each element in the "R_Array". verification environment, the queues can used for |   Downloads   SystemVerilog extends Verilog by introducing C like data types. Associative arrays are like traditional arrays except they uses strings as their indexes rather than numbers. the array. Syntax: arrayname[string]=value. Have a look at line5: event done = ack; Now ack and done are synonymous with each other, whenever one event is triggered the other is as well, since each is triggered once you get 4... First, some background: It's likely you're getting "Timing requirements not met" because of the size of the image - 50x50x8x3 is a fair number of storage bits, moreso if it's attempting to store them into logic instead of on-chip RAM. Otherwise the loop can not determine how to how many times to loop for i. Since you did not explicitly provide data types for your parameters, they are implicitly defined with the type of the default initialization or the type of any expression they ore overridden with. The short answer is: use the PHP Foreach loop or For loop to iterate through the elements. The key is of string type to declare the items. The rules for structs are the same for integral bit vectors. always_comb blocks execute procedurally, top to bottom. scoreboarding purpose. Turns out this is a modelsim bug. example shows the following System Verilog features: * The second "new" method is called with "WIDTH" and created a dynamic array of "CELL" class instances call "C_Array". simple_State has 11 rows and 11 columns, so a 4 bit for row index and column index is enough. In [email protected](posedge clk) use non-blocking assignments (<=). The second "new" method is called with "WIDTH" and created a "FRAME" is created and the constructor is passed the arguments (3,3) thus An associative array implements a lookup table of the elements of its declared type. elements in the FIFO is done using queue methods. Looping over an array and any other objects in JavaScript is a common problem lots of programmers encounter the most. SystemVerilog arrays are data structures that allow storage of many values in a single variable. foreach (two [i,j]) // … Traditionally, Verilog has been used for modelling hardware at RTL and at Gate level abstractions. There is no disable_iff keywords, it is disable iff (without the underscore). On the other hand, in SystemVerilog you can declare an array using range or size (i.e.... You are performing unsigned arithmetic, as noted the MSB is 0 not 1 (negative) as expected. In the associative arrays the storage is allocated only when we use it not initially like in dynamic arrays. SystemVerilog has many methods to operate on these instances. This document specifies the Accellera extensions for a higher level of abstraction for modeling and verification with the Verilog Hardware Description Language. google_ad_channel ="4645973219"; It only compares the handles. module FIFO #(parameter int DEPTH = 31, parameter int WIDTH = 8) (, else if (WENb == 0 && mem.size() < DEPTH). ; let RUN_STATES = 3'b01? //-->, Home   |    and call the "new" method. ; // or parameter COMP_STATES = 3'b00? |   eBooks   SystemVerilog arrays can be either packed or unpacked. Associative array is one of aggregate data types available in system verilog. They have enhanced carry logic that is significantly faster than what you can create in the configurable fabric. It is illegal syntax. The short answer is: use the PHP Foreach loop or For loop to iterate through the elements. The simulator also needs to handle for the case that slba_previous[nsid] doesn't exist And there for have no i to index. You need to declare an array using range (i.e. All code is available on EDA Playground https://www.edaplayground.com/x/4B2r. class.The second run actually calls the "new" class method between each The first class called "CELL" has several random variables and a Another "for" loop is used to iterate through each element of "C_Array" and call the "new" method. How to Loop through an Array in JavaScript. google_ad_width = 728; Static Arrays Dynamic Arrays Associative Arrays Queues Static Arrays A static array is one whose size is known before compilation time. The package "DynPkg" contains declarations for several is also modeled using SystemVerilog 2-state int and bit types. The data type to be used as an index serves as the lookup key and imposes an ordering When the size of the collection is unknown or the data space is sparse, an associative array is a better option. The So the associative arrays are mainly used to model the sparse memories. The The SystemVerilog Language Reference Manual (LRM) was specified by the Accellera SystemVerilog com-mittee. The delete() method removes the entry at the specified index. ); This same even though three different values have been assigned. // associative array A function is intended to be evaluated during simulation. "classes" they must be constructed with "new" individually. Given the code snippet, check_device is the name of the function you are defining. When using a foreach on an double associative array, you need to include all the significant indexes. Array: Arrays in PHP is a type of data structure that allows to storing multiple elements of similar data type under a single variable thereby saving the effort of creating a different variable for every data. these handles is set to NULL.Since the elements of the dynamic arrays are Instead, we could use the respective subject’s names as the keys in our associative array, and the value would be their respective marks gained. Declaring Associative Arrays of nam_dat with string index. My problem was that, whilst the variables were declared correctly on both ends, one of my constructors was written: function new(ref int num_items); where it should have rather been function new(ref int unsigned num_items); Thank you Qiu.... For your first question "why typedef cannot be used locally?" Define your types in... Qiu did point me to the issue with my code. example is a simple FIFO that is modeled with a SystemVerilog queue. When using a foreach on an double associative array, you need to include all the significant indexes. Otherwise the loop can not determine how to how many times to loop for i. In the constraint, I have used (i%2), still it is showing this warning: Warning : (vsim-3829) Non-existent associative array entry. The problem seems to be indeed vendor-specific, as @toolic mentioned. SystemVerilog also has let, which is more appropriate for for compile time evaluation (it supports... queue.delete(int'(queue.find_first_index( x ) with ( x == obj_to_del ))); works for me. google_ad_height = 15; In this code, I am facing 2 issues in QuestaSIM. popping data in and out of the FIFO as well as checking the number of When a A user defined type is only compatible with itself. Multidimensional associative array is often used to store data in group relation. Free; end; Erlang. By now you know that my favorite way to step through an array is with a foreach loop. arrays of class instances. Packed array refers to dimensions declared after the type and before the data identifier name. Otherwise the loop can not determine how to how many times to loop for i. google_ad_format = "728x15_0ads_al"; I'm guessing you're analyzing only one simulation, though. correct behavior as all three elements of the array hold the same handle The solver is failing because it sees that o1.o2 and o2_local are different objects and thus aren't "equal". creating a 3x3 dynamic array of the class "CELL". System Verilog Arrays | System Verilog Tutorial, Arrays in system verilog : An array is a collection of variables, all of the same type , and accessed using the same name plus one or more indices. how to use 2 Dimensional array in Verilog, Systemverilog: Simulation error when passing structs as module input\outputs. first() assigns to the given index … The Result is updated and Z is not re-evaluated. In Associative arrays Elements Not Allocated until Used. Associative Arrays : An Associative array is a better option when the size of the collection is unknown or the data space is sparse. First, you can't have duplicate enumeration identifiers in the same scope so you can't have a composite "all_inst". SystemVerilog adds extended and new data types to Verilog for better encapsulation and compactness. google_color_text = "000000"; They are: The num() or size() method returns the number of entries in the associative array. without calling the "new" class method between each array assignment. Systemverilog doesn't allow variable declarations after call to super.foo()? Section 7.8 Associative arrays from SystemVerilog standard IEEE 1800-2017 The way you have defined initial values is not typical. Please see section 7.12.1 Array locator methods in the IEEE 1800-2012 LRM. By doing this, you create new handles. Either use and initial block or a reset. You might have to write for your compiler input var foo foo_inst, But it would be better to use a ref when a port is really a handle. Is this what your design looks like? sum3e variable depends on sum3a and sum3b but at the same time sum3a and sum3b value is changing because of non-blocking assignments,This will results in logical errors. Declaring Associative Arrays In Verilog input logic a[10] logic is not allowed and will cause Single value range is not allowed in this mode of verilog error. Updating a classes' variable in a constructor through pass by reference? FR.R_Array[i].C_Array[j].C); Simple SystemVerilog Queue Example - System verilog packed array of structs. 1 : 0;

iterate through associative array systemverilog

[duplicate] Ask Question Asked 11 years ago. Yes the returned queue has an element type that matches the associative array index type. The values you get, are the current values in the The next class declaration "ROW" creates a Since both RTL and Gate level abstraction are static/fixed (non-dynamic), Verilog supported only static variables. width and depth of the FIFO are controlled using parameters. So you need to dereference the pointer as in the following statement: *mem_req_rdy =... Well I have found out the answer of the question, so here I am posting it. the "R_Array", each handle to the class instance needs to be constructed. They are the three different values that were assigned. Articles/ Tutorials   contention and net resolution are not a concern, 2-state types can improve view source. You need to declare the inputs, outputs and variables used as signed, for automatic sign extension. Each Notice the results of this run. google_color_url = "000000"; system verilog assertion disable condition. dynamic array of "CELL" class instances call "C_Array". |   Links   However at this point each of The clean and easy solution here is to assign a default value Carryout at the beginning of the always_comb block. Returning default value. by Abhiram Rao. functional_coverage not showing proper result. Packed array refers to dimensions declared after the type and before the data identifier Struct is defined with the Struct keyword followed by variables of multiple data type with in the curly braces. Given that you had: vc_putScalar(mem_req_rdy, mm->req_cmd_ready()); I am guessing that mem_req_rdy is of pointer type svLogic* (since from the name of the function vc_putScalar, it seems that it intends to change the value held in mem_req_rdy). Here is an example. Syntax for looping through lower dimension of multidimensional associative array in a constraint. Also, we will see, PowerShell loop through an array using ForEach-Object loop, While loop, do-while loop, and do-until loop. Another "for" loop is used to iterate through each element of "C_Array" Class-Based SystemVerilog (Days 2 … to the class instance. The only thing you loose is x->z transitions. We have already discussed about dynamic array, which is useful for dealing with contiguous collection of variables whose number changes dynamically. So for example, any reg or wire in Verilog would be instantiated/mapped at the beginning of simulation and would remain... system-verilog,function-coverage,questasim, What you are asking for cannot be done, nor does it make any sense. Some simulators support evaluating function during compile/elaboration, but it doesn't appear to be a requirement. "for" loop is used to iterate through each element in the "R_Array". So when you... From your code snippet: xxx_model is a parameterized module that takes a parameter of type string named inst_name. How to loop through lower dimension in 2 dimensional associative array in a constraint? A double linked list is a chain of data structures called nodes. Associative array stores the data in the form of key and value pairs where the key can be an integer or string. For some reasons it works when I write the record elements in the lower case. The design may always have an even number of entries, but it looks like QuestaSIM's constraint solver is more pessimistic and and wants to consider all possibilities. So the associative arrays are mainly used to model the sparse memories. — webmaster@electroSofts.com. In this Names [i] + ': ' + DataField. foo.reg_fields.first( s ) ). I think you may be confused about why the events are printed multiple times? array, R_Array[i].C_Array[j] = new; // construct each You need to put your constraint in terms of a foreach loop. I'm posting this as an answer because I cannot put a photo in a comment. See https://verificationacademy.com/forums/coverage/how-get-values-different-bins-coverpoint. nam_dat Associative Array: Associative arrays are used to store key-value pairs. I played around with this a little bit and came up with an associative array of these types. If you can depend on the encoding, then you can define your collection with a wildcard and use the wildcard equality operator or inside operator let COMP_STATES = 3'b00? Wires can have multiple continuous drivers, and variables can have a single continuous driver, or multiple procedural assignment. Loop Through an Associative Array. vcover merge -testassociated This flag will keep an eye on each test's contribution to the coverage. Otherwise the loop can not determine how to how many times to loop for i. dynamic array of the class "ROW". Best way to check if variable is part of collection of enums? All of the builtin find_ methods require a with (expression). example shows how handles to class objects work. ValueFromIndex [i]); end; DataField. example demonstrates how to model a parameterized dynamic 2-dimensional $display("CELL[%0d][%0d] = %b %b %b",i, j. FR.R_Array[i].C_Array[j].A, FR.R_Array[i].C_Array[j].B,          constraint on those variables. array of classes. Arrays and Queues Dynamic Arrays • Queues • Working with Queues • Queue Methods • Associative Arrays • Associative Array Methods • Foreach. Properties can have local variables but the local variables cannot be defined inline with assert. SystemVerilog foreach specifies iteration over the elements of an array. The operator -> is used to... You need to use a local variable, see IEEE Std 1800-2012 § 16.10 Local variables Here is a simple example: property p_PropA; int count; @(posedge clk) ($rose(active),count=config) |-> (active,count--)[*] ##1 (~active && count==0); endproperty ... For most cases you can't beat the dedicated adder resources found in FPGAs. A foreach loop is only used to iterate over such arrays and is the Verilog arrays can only be referenced one element at a time. the class instance at that specific time. Finally, in the module "top", an instance of system-verilog,questasim. top level module then simply calls the built-in randomize function and It parses the key-value pairs of elements one-by-one and prints them in the output using the PHP echo function . In the above awk syntax: arrayname is the name of the array. When using a foreach on an double associative array, you need to include all the significant indexes. There are a couple of ways you could do this. In this tutorial, we will discuss how to loop through an array in PowerShell using for loop. The "FRAME" class also includes a You need to loop through the full slba_previous[id,i] and then check if id==nsid. First declare the Linked list type and then take instances of it. When the size of the collection is unknown or the data space is sparse, an associative array is a better option. dynamic array foo, if ( All variables in a task or function must be declared before any operation. In SystemVerilog, you can declare an explicit event and wait on that. As with There are several ways to loop over an array in JavaScript. Associative Arrays Example: This example shows the following System Verilog features: * Classes ... the "R_Array", each handle to the class instance needs to be constructed. The associative array contains elements in which all elements have a key that is manually assigned by the user. delete() removes the entry from specified index. "for" loop is used to iterate through each element in the "R_Array". verification environment, the queues can used for |   Downloads   SystemVerilog extends Verilog by introducing C like data types. Associative arrays are like traditional arrays except they uses strings as their indexes rather than numbers. the array. Syntax: arrayname[string]=value. Have a look at line5: event done = ack; Now ack and done are synonymous with each other, whenever one event is triggered the other is as well, since each is triggered once you get 4... First, some background: It's likely you're getting "Timing requirements not met" because of the size of the image - 50x50x8x3 is a fair number of storage bits, moreso if it's attempting to store them into logic instead of on-chip RAM. Otherwise the loop can not determine how to how many times to loop for i. Since you did not explicitly provide data types for your parameters, they are implicitly defined with the type of the default initialization or the type of any expression they ore overridden with. The short answer is: use the PHP Foreach loop or For loop to iterate through the elements. The key is of string type to declare the items. The rules for structs are the same for integral bit vectors. always_comb blocks execute procedurally, top to bottom. scoreboarding purpose. Turns out this is a modelsim bug. example shows the following System Verilog features: * The second "new" method is called with "WIDTH" and created a dynamic array of "CELL" class instances call "C_Array". simple_State has 11 rows and 11 columns, so a 4 bit for row index and column index is enough. In [email protected](posedge clk) use non-blocking assignments (<=). The second "new" method is called with "WIDTH" and created a "FRAME" is created and the constructor is passed the arguments (3,3) thus An associative array implements a lookup table of the elements of its declared type. elements in the FIFO is done using queue methods. Looping over an array and any other objects in JavaScript is a common problem lots of programmers encounter the most. SystemVerilog arrays are data structures that allow storage of many values in a single variable. foreach (two [i,j]) // … Traditionally, Verilog has been used for modelling hardware at RTL and at Gate level abstractions. There is no disable_iff keywords, it is disable iff (without the underscore). On the other hand, in SystemVerilog you can declare an array using range or size (i.e.... You are performing unsigned arithmetic, as noted the MSB is 0 not 1 (negative) as expected. In the associative arrays the storage is allocated only when we use it not initially like in dynamic arrays. SystemVerilog has many methods to operate on these instances. This document specifies the Accellera extensions for a higher level of abstraction for modeling and verification with the Verilog Hardware Description Language. google_ad_channel ="4645973219"; It only compares the handles. module FIFO #(parameter int DEPTH = 31, parameter int WIDTH = 8) (, else if (WENb == 0 && mem.size() < DEPTH). ; let RUN_STATES = 3'b01? //-->, Home   |    and call the "new" method. ; // or parameter COMP_STATES = 3'b00? |   eBooks   SystemVerilog arrays can be either packed or unpacked. Associative array is one of aggregate data types available in system verilog. They have enhanced carry logic that is significantly faster than what you can create in the configurable fabric. It is illegal syntax. The short answer is: use the PHP Foreach loop or For loop to iterate through the elements. The simulator also needs to handle for the case that slba_previous[nsid] doesn't exist And there for have no i to index. You need to declare an array using range (i.e. All code is available on EDA Playground https://www.edaplayground.com/x/4B2r. class.The second run actually calls the "new" class method between each The first class called "CELL" has several random variables and a Another "for" loop is used to iterate through each element of "C_Array" and call the "new" method. How to Loop through an Array in JavaScript. google_ad_width = 728; Static Arrays Dynamic Arrays Associative Arrays Queues Static Arrays A static array is one whose size is known before compilation time. The package "DynPkg" contains declarations for several is also modeled using SystemVerilog 2-state int and bit types. The data type to be used as an index serves as the lookup key and imposes an ordering When the size of the collection is unknown or the data space is sparse, an associative array is a better option. The So the associative arrays are mainly used to model the sparse memories. The The SystemVerilog Language Reference Manual (LRM) was specified by the Accellera SystemVerilog com-mittee. The delete() method removes the entry at the specified index. ); This same even though three different values have been assigned. // associative array A function is intended to be evaluated during simulation. "classes" they must be constructed with "new" individually. Given the code snippet, check_device is the name of the function you are defining. When using a foreach on an double associative array, you need to include all the significant indexes. Array: Arrays in PHP is a type of data structure that allows to storing multiple elements of similar data type under a single variable thereby saving the effort of creating a different variable for every data. these handles is set to NULL.Since the elements of the dynamic arrays are Instead, we could use the respective subject’s names as the keys in our associative array, and the value would be their respective marks gained. Declaring Associative Arrays of nam_dat with string index. My problem was that, whilst the variables were declared correctly on both ends, one of my constructors was written: function new(ref int num_items); where it should have rather been function new(ref int unsigned num_items); Thank you Qiu.... For your first question "why typedef cannot be used locally?" Define your types in... Qiu did point me to the issue with my code. example is a simple FIFO that is modeled with a SystemVerilog queue. When using a foreach on an double associative array, you need to include all the significant indexes. Otherwise the loop can not determine how to how many times to loop for i. In the constraint, I have used (i%2), still it is showing this warning: Warning : (vsim-3829) Non-existent associative array entry. The problem seems to be indeed vendor-specific, as @toolic mentioned. SystemVerilog also has let, which is more appropriate for for compile time evaluation (it supports... queue.delete(int'(queue.find_first_index( x ) with ( x == obj_to_del ))); works for me. google_ad_height = 15; In this code, I am facing 2 issues in QuestaSIM. popping data in and out of the FIFO as well as checking the number of When a A user defined type is only compatible with itself. Multidimensional associative array is often used to store data in group relation. Free; end; Erlang. By now you know that my favorite way to step through an array is with a foreach loop. arrays of class instances. Packed array refers to dimensions declared after the type and before the data identifier name. Otherwise the loop can not determine how to how many times to loop for i. google_ad_format = "728x15_0ads_al"; I'm guessing you're analyzing only one simulation, though. correct behavior as all three elements of the array hold the same handle The solver is failing because it sees that o1.o2 and o2_local are different objects and thus aren't "equal". creating a 3x3 dynamic array of the class "CELL". System Verilog Arrays | System Verilog Tutorial, Arrays in system verilog : An array is a collection of variables, all of the same type , and accessed using the same name plus one or more indices. how to use 2 Dimensional array in Verilog, Systemverilog: Simulation error when passing structs as module input\outputs. first() assigns to the given index … The Result is updated and Z is not re-evaluated. In Associative arrays Elements Not Allocated until Used. Associative Arrays : An Associative array is a better option when the size of the collection is unknown or the data space is sparse. First, you can't have duplicate enumeration identifiers in the same scope so you can't have a composite "all_inst". SystemVerilog adds extended and new data types to Verilog for better encapsulation and compactness. google_color_text = "000000"; They are: The num() or size() method returns the number of entries in the associative array. without calling the "new" class method between each array assignment. Systemverilog doesn't allow variable declarations after call to super.foo()? Section 7.8 Associative arrays from SystemVerilog standard IEEE 1800-2017 The way you have defined initial values is not typical. Please see section 7.12.1 Array locator methods in the IEEE 1800-2012 LRM. By doing this, you create new handles. Either use and initial block or a reset. You might have to write for your compiler input var foo foo_inst, But it would be better to use a ref when a port is really a handle. Is this what your design looks like? sum3e variable depends on sum3a and sum3b but at the same time sum3a and sum3b value is changing because of non-blocking assignments,This will results in logical errors. Declaring Associative Arrays In Verilog input logic a[10] logic is not allowed and will cause Single value range is not allowed in this mode of verilog error. Updating a classes' variable in a constructor through pass by reference? FR.R_Array[i].C_Array[j].C); Simple SystemVerilog Queue Example - System verilog packed array of structs. 1 : 0;