fbpx

Top 100 System Verilog Interview Questions and Answers

Top 100 System Verilog Interview Questions and Answers
Contents show

1. What is System Verilog?

Answer: System Verilog is an extension of Verilog, adding features for design and verification. It supports object-oriented programming, randomization, and other constructs for efficient hardware modeling.

module and_gate(input a, input b, output y);
   assign y = a & b;
endmodule

Reference: System Verilog IEEE Standard 1800-2017


2. What is a Testbench in System Verilog?

Answer: A testbench is a simulation environment used to verify the functionality of a design. It generates stimulus and monitors the responses to validate the design’s correctness.

module tb_and_gate;
   reg a, b;
   wire y;

   and_gate uut(.a(a), .b(b), .y(y));

   initial begin
      a = 1'b0;
      b = 1'b1;
      #5;
      $display("a AND b = %b", y);
   end
endmodule

Reference: System Verilog IEEE Standard 1800-2017


3. Explain the always block in System Verilog.

Answer: The always block defines a region of code that executes continuously based on sensitivity list events (e.g., posedge/negedge of signals). It’s used for describing sequential and combinational logic.

always @(posedge clk) begin
   if (reset) begin
      count <= 4'b0000;
   end else begin
      count <= count + 1;
   end
end

Reference: System Verilog IEEE Standard 1800-2017


4. What is a task in System Verilog?

Answer: A task is a reusable block of code that can be called with arguments. It’s commonly used for organizing and encapsulating simulation tasks.

task adder(input int a, int b, output int sum);
   sum = a + b;
endtask

Reference: System Verilog IEEE Standard 1800-2017


5. Explain the difference between always @(*) and always @(posedge/negedge).

Answer: always @(*) is sensitive to any change in the inputs. It’s used for combinatorial logic. always @(posedge/negedge) is sensitive to clock edges and is used for sequential logic.

always @(*) begin
   y = a & b;
end

always @(posedge clk) begin
   if (reset) begin
      count <= 4'b0000;
   end else begin
      count <= count + 1;
   end
end

Reference: System Verilog IEEE Standard 1800-2017


6. What is the purpose of the initial block in System Verilog?

Answer: The initial block is used for providing an initial value to signals and for specifying the behavior of the simulation at time 0.

initial begin
   a = 1'b0;
   b = 1'b1;
   #5;
   $display("a AND b = %b", y);
end

Reference: System Verilog IEEE Standard 1800-2017


7. Explain the fork-join construct in System Verilog.

Answer: fork-join is used for concurrent execution of blocks. fork creates parallel threads, and join waits for all threads to complete.

fork
   task1;
   task2;
join

Reference: System Verilog IEEE Standard 1800-2017


8. What is the significance of always_ff in System Verilog?

Answer: always_ff is used for describing synchronous logic that is sensitive to a clocking event. It ensures that the code is synthesizable for hardware.

always_ff @(posedge clk) begin
   if (reset) begin
      count <= 4'b0000;
   end else begin
      count <= count + 1;
   end
end

Reference: System Verilog IEEE Standard 1800-2017


9. Explain the use of typedef in System Verilog.

Answer: typedef is used to define custom data types for better code readability and maintainability.

typedef logic [7:0] byte;
byte data;

Reference: System Verilog IEEE Standard 1800-2017


10. What is the purpose of the disable statement in System Verilog?

Answer: The disable statement is used to halt the execution of a named block or begin-end block.

initial begin
   #10;
   disable my_task; // Halts execution of task 'my_task'
end

Reference: System Verilog IEEE Standard 1800-2017


11. Explain the concept of bitwise and logical operators in System Verilog.

Answer: Bitwise operators perform operations on individual bits. Logical operators perform operations on entire vectors.

// Bitwise AND operation
a = 4'b1010;
b = 4'b1100;
result = a & b; // result = 4'b1000

// Logical AND operation
a = 4'b1010;
b = 4'b1100;
result = a && b; // result = 1'b1 (true)

Reference: System Verilog IEEE Standard 1800-2017


12. How do you declare a packed and unpacked array in System Verilog?

Answer: Packed arrays store multiple variables in a single element. Unpacked arrays are arrays of variables.

// Packed array
logic [3:0] packed_array;

// Unpacked array
logic unpacked_array[0:3];

Reference: System Verilog IEEE Standard 1800-2017


13. What is the purpose of the rand keyword in System Verilog?

Answer: The rand keyword is used to define random variables for randomization in verification environments.

class transaction;
   rand int addr;
   rand bit [7:0] data;
endclass

Reference: System Verilog IEEE Standard 1800-2017


14. Explain the concept of covergroup in System Verilog.

Answer: A covergroup is used to collect coverage information for functional verification. It defines a set of coverage points.

covergroup packet_coverage;
   coverpoint src_addr {
      bins valid = {[8'h00:8'h0F]};
   }
   coverpoint dest_addr {
      bins valid = {[8'h10:8'h1F]};
   }
endgroup

Reference: System Verilog IEEE Standard 1800-2017


15. How do you define a sequence in System Verilog?

Answer: A sequence defines a specific sequence of events that need to occur in the simulation.

sequence my_sequence;
   a ##1 b ##1 c;
endsequence

Reference: System Verilog IEEE Standard 1800-2017


16. What is the purpose of virtual interfaces in System Verilog?

Answer: Virtual interfaces allow modules to communicate without knowing the hierarchy of the design.

interface intf;
   logic a, b;
   mod_if mod_intf;
endinterface

mod_if u1_intf, u2_intf;
u1_intf = intf;
u2_intf = intf;

Reference: System Verilog IEEE Standard 1800-2017


17. Explain the concept of assertions in System Verilog.

Answer: Assertions are used to specify properties or behaviors that must hold true during simulation.

property non_negative;
   @(posedge clk) $rose(enable) |-> data >= 0;
endproperty

// Usage
assert property (non_negative);

Reference: System Verilog IEEE Standard 1800-2017


18. How do you perform dynamic memory allocation in System Verilog?

Answer: Dynamic memory allocation is done using new and delete operators.

int* ptr;
ptr = new[10]; // Allocates an array of 10 integers

// ...

delete ptr; // Deallocates memory

Reference: System Verilog IEEE Standard 1800-2017


19. What is a DPI (Direct Programming Interface) task in System Verilog?

Answer: DPI tasks allow System Verilog to call functions written in other languages like C or C++.

import "DPI-C" function void my_c_function();
   // ...
endfunction

Reference: System Verilog IEEE Standard 1800-2017


20. How do you handle clock-domain crossing in System Verilog?

Answer: CDC is managed using synchronization elements like dual flip-flops or FIFO buffers to ensure data integrity between different clock domains.

always @(posedge clk1 or posedge clk2) begin
   if (sync_condition) begin
      // Synchronize data
   end
end

Reference: System Verilog IEEE Standard 1800-2017


21. Explain the use of final in System Verilog.

Answer: The final keyword is used to ensure that an extended class cannot be further extended.

class base;
   // ...
   final function void my_function();
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


22. What is the purpose of the restrict keyword in System Verilog?

Answer: The restrict keyword is used to prevent certain operations in a task or function.

function int my_function(int a, int b) restrict;
   // ...
endfunction

Reference: System Verilog IEEE Standard 1800-2017


23. Explain the concept of bitstream in System Verilog.

Answer: A bitstream is a sequential stream of bits used for configuration or programming of devices like FPGAs.

logic [31:0] config_data;
initial begin
   config_data = 32'hA5F0123;
   // Program device with config_data
end

Reference: System Verilog IEEE Standard 1800-2017


24. How do you handle clock-domain crossing in System Verilog?

Answer: CDC is managed using synchronization elements like dual flip-flops or FIFO buffers to ensure data integrity between different clock domains.

always @(posedge clk1 or posedge clk2) begin
   if (sync_condition) begin
      // Synchronize data
   end
end

Reference: System Verilog IEEE Standard 1800-2017


25. Explain the use of final in System Verilog.

Answer: The final keyword is used to ensure that an extended class cannot be further extended.

class base;
   // ...
   final function void my_function();
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


26. What is the purpose of the restrict keyword in System Verilog?

Answer: The restrict keyword is used to prevent certain operations in a task or function.

function int my_function(int a, int b) restrict;
   // ...
endfunction

Reference: System Verilog IEEE Standard 1800-2017


27. Explain the concept of bitstream in System Verilog.

Answer: A bitstream is a sequential stream of bits used for configuration or programming of devices like FPGAs.

logic [31:0] config_data;
initial begin
   config_data = 32'hA5F0123;
   // Program device with config_data
end

Reference: System Verilog IEEE Standard 1800-2017


28. How do you handle clock-domain crossing in System Verilog?

Answer: CDC is managed using synchronization elements like dual flip-flops or FIFO buffers to ensure data integrity between different clock domains.

always @(posedge clk1 or posedge clk2) begin
   if (sync_condition) begin
      // Synchronize data
   end
end

Reference: System Verilog IEEE Standard 1800-2017


29. Explain the use of final in System Verilog.

Answer: The final keyword is used to ensure that an extended class cannot be further extended.

class base;
   // ...
   final function void my_function();
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


30. What is the purpose of the restrict keyword in System Verilog?

Answer: The restrict keyword is used to prevent certain operations in a task or function.

function int my_function(int a, int b) restrict;
   // ...
endfunction

Reference: System Verilog IEEE Standard 1800-2017


31. How do you use virtual functions in System Verilog?

Answer: Virtual functions are used in classes to enable late binding. They allow a function to be overridden in derived classes.

class base;
   virtual function void my_function();
      // ...
   endfunction
endclass

class derived extends base;
   function void my_function();
      // Override base class function
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


32. What is the significance of disable fork in System Verilog?

Answer: disable fork is used to terminate parallel threads created by a fork-join construct.

fork
   task1;
   task2;
join_any
   // Code after join_any executes when any thread completes
disable fork; // Terminate all remaining threads

Reference: System Verilog IEEE Standard 1800-2017


33. Explain the use of overload in System Verilog.

Answer: The overload keyword allows multiple tasks or functions with the same name but different argument lists in the same scope.

class my_class;
   function void my_function(int a);
      // ...
   endfunction

   function void my_function(int a, int b);
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


34. How do you handle multi-dimensional arrays in System Verilog?

Answer: Multi-dimensional arrays are declared by specifying multiple range dimensions.

logic [3:0][7:0] matrix;

// Accessing elements
matrix[2][5] = 8'hFF;

Reference: System Verilog IEEE Standard 1800-2017


35. Explain the concept of uvm_sequence in System Verilog.

Answer: uvm_sequence is a fundamental building block of the UVM (Universal Verification Methodology) framework used for stimulus generation in verification environments.

class my_sequence extends uvm_sequence;
   // Define sequence items and behavior here
endclass

Reference: UVM IEEE Standard 1800.2-2020


36. What is the purpose of wait and wait_order in System Verilog assertions?

Answer: wait specifies a condition that must eventually become true. wait_order defines the order in which properties should be checked.

property p1;
   @(posedge clk) a |-> ##1 b;
endproperty

property p2;
   @(posedge clk) ##1 a |-> b;
endproperty

assert property (p1) else $fatal("p1 failed");
assert property (p2) else $fatal("p2 failed");

Reference: System Verilog IEEE Standard 1800-2017


37. How do you use clocking events in System Verilog?

Answer: clocking events are used to synchronize signals with clock edges, enabling precise event modeling.

clocking my_clocking @(posedge clk);
   input a, b;
   output y;

   default input #1 output #1;

   // Define clocking events here
endclocking

Reference: System Verilog IEEE Standard 1800-2017


38. Explain the concept of mailbox in System Verilog.

Answer: A mailbox is a synchronization primitive used for communication between different processes or threads.

mailbox mb;

initial begin
   // Task 1
   mb.put(5);
end

initial begin
   // Task 2
   int data;
   mb.get(data);
end

Reference: System Verilog IEEE Standard 1800-2017


39. What is the purpose of initial and final blocks in System Verilog?

Answer: initial blocks define behavior at time 0 or for simulation initialization. final blocks define cleanup or summary actions at the end of simulation.

initial begin
   // Initialization code
end

final begin
   // Cleanup code
end

Reference: System Verilog IEEE Standard 1800-2017


40. How do you use disable and # (delay) in System Verilog?

Answer: disable halts execution at a specific point. # introduces a delay in simulation.

initial begin
   #10; // Wait for 10 time units
   disable my_task; // Halt execution of task 'my_task'
end

Reference: System Verilog IEEE Standard 1800-2017


41. Explain the use of randc in System Verilog.

Answer: randc is used to randomize variables with constraints but in a complementary distribution.

randc int data;
constraint valid_data { data > 0; }

Reference: System Verilog IEEE Standard 1800-2017


42. What is the purpose of sequence_item in System Verilog?

Answer: sequence_item is a base class for creating items to be used in sequences for verification.

class my_sequence_item;
   int addr;
   bit [7:0] data;
   // ...
endclass

Reference: UVM IEEE Standard 1800.2-2020


43. How do you use disable fork in System Verilog?

Answer: disable fork is used to terminate parallel threads created by a fork-join construct.

fork
   task1;
   task2;
join_any
   // Code after join_any executes when any thread completes
disable fork; // Terminate all remaining threads

Reference: System Verilog IEEE Standard 1800-2017


44. Explain the use of overload in System Verilog.

Answer: The overload keyword allows multiple tasks or functions with the same name but different argument lists in the same scope.

class my_class;
   function void my_function(int a);
      // ...
   endfunction

   function void my_function(int a, int b);
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


45. How do you handle multi-dimensional arrays in System Verilog?

Answer: Multi-dimensional arrays are declared by specifying multiple range dimensions.

logic [3:0][7:0] matrix;

// Accessing elements
matrix[2][5] = 8'hFF;

Reference: System Verilog IEEE Standard 1800-2017


46. Explain the concept of uvm_sequence in System Verilog.

Answer: uvm_sequence is a fundamental building block of the UVM (Universal Verification Methodology) framework used for stimulus generation in verification environments.

class my_sequence extends uvm_sequence;
   // Define sequence items and behavior here
endclass

Reference: UVM IEEE Standard 1800.2-2020


47. What is the purpose of wait and wait_order in System Verilog assertions?

Answer: wait specifies a condition that must eventually become true. wait_order defines the order in which properties should be checked.

property p1;
   @(posedge clk) a |-> ##1 b;
endproperty

property p2;
   @(posedge clk) ##1 a |-> b;
endproperty

assert property (p1) else $fatal("p1 failed");
assert property (p2) else $fatal("p2 failed");

Reference: System Verilog IEEE Standard 1800-2017


48. How do you use clocking events in System Verilog?

Answer: clocking events are used to synchronize signals with clock edges, enabling precise event modeling.

clocking my_clocking @(posedge clk);
   input a, b;
   output y;

   default input #1 output #1;

   // Define clocking events here
endclocking

Reference: System Verilog IEEE Standard 1800-2017


49. Explain the concept of mailbox in System Verilog.

Answer: A mailbox is a synchronization primitive used for communication between different processes or threads.

mailbox mb;

initial begin
   // Task 1
   mb.put(5);
end

initial begin
   // Task 2
   int data;
   mb.get(data);
end

Reference: System Verilog IEEE Standard 1800-2017


50. What is the purpose of initial and final blocks in System Verilog?

Answer: initial blocks define behavior at time 0 or for simulation initialization. final blocks define cleanup or summary actions at the end of simulation.

initial begin
   // Initialization code
end

final begin
   // Cleanup code
end

Reference: System Verilog IEEE Standard 1800-2017


51. How do you use disable and # (delay) in System Verilog?

Answer: disable halts execution at a specific point. # introduces a delay in simulation.

initial begin
   #10; // Wait for 10 time units
   disable my_task; // Halt execution of task 'my_task'
end

Reference: System Verilog IEEE Standard 1800-2017


52. Explain the use of randc in System Verilog.

Answer: randc is used to randomize variables with constraints but in a complementary distribution.

randc int data;
constraint valid_data { data > 0; }

Reference: System Verilog IEEE Standard 1800-2017


53. What is the purpose of sequence_item in System Verilog?

Answer: sequence_item is a base class for creating items to be used in sequences for verification.

class my_sequence_item;
   int addr;
   bit [7:0] data;
   // ...
endclass

Reference: UVM IEEE Standard 1800.2-2020


54. How do you use disable fork in System Verilog?

Answer: disable fork is used to terminate parallel threads created by a fork-join construct.

fork
   task1;
   task2;
join_any
   // Code after join_any executes when any thread completes
disable fork; // Terminate all remaining threads

Reference: System Verilog IEEE Standard 1800-2017


55. Explain the use of overload in System Verilog.

Answer: The overload keyword allows multiple tasks or functions with the same name but different argument lists in the same scope.

class my_class;
   function void my_function(int a);
      // ...
   endfunction

   function void my_function(int a, int b);
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


56. How do you handle multi-dimensional arrays in System Verilog?

Answer: Multi-dimensional arrays are declared by specifying multiple range dimensions.

logic [3:0][7:0] matrix;

// Accessing elements
matrix[2][5] = 8'hFF;

Reference: System Verilog IEEE Standard 1800-2017


57. Explain the concept of uvm_sequence in System Verilog.

Answer: uvm_sequence is a fundamental building block of the UVM (Universal Verification Methodology) framework used for stimulus generation in verification environments.

class my_sequence extends uvm_sequence;
   // Define sequence items and behavior here
endclass

Reference: UVM IEEE Standard 1800.2-2020


58. What is the purpose of wait and wait_order in System Verilog assertions?

Answer: wait specifies a condition that must eventually become true. wait_order defines the order in which properties should be checked.

property p1;
   @(posedge clk) a |-> ##1 b;
endproperty

property p2;
   @(posedge clk) ##1 a |-> b;
endproperty

assert property (p1) else $fatal("p1 failed");
assert property (p2) else $fatal("p2 failed");

Reference: System Verilog IEEE Standard 1800-2017


59. How do you use clocking events in System Verilog?

Answer: clocking events are used to synchronize signals with clock edges, enabling precise event modeling.

clocking my_clocking @(posedge clk);
   input a, b;
   output y;

   default input #1 output #1;

   // Define clocking events here
endclocking

Reference: System Verilog IEEE Standard 1800-2017


60. Explain the concept of mailbox in System Verilog.

Answer: A mailbox is a synchronization primitive used for communication between different processes or threads.

mailbox mb;

initial begin
   // Task 1
   mb.put(5);
end

initial begin
   // Task 2
   int data;
   mb.get(data);
end

Reference: System Verilog IEEE Standard 1800-2017


61. What is the purpose of initial and final blocks in System Verilog?

Answer: initial blocks define behavior at time 0 or for simulation initialization. final blocks define cleanup or summary actions at the end of simulation.

initial begin
   // Initialization code
end

final begin
   // Cleanup code
end

Reference: System Verilog IEEE Standard 1800-2017


62. How do you use disable and # (delay) in System Verilog?

Answer: disable halts execution at a specific point. # introduces a delay in simulation.

initial begin
   #10; // Wait for 10 time units
   disable my_task; // Halt execution of task 'my_task'
end

Reference: System Verilog IEEE Standard 1800-2017


63. Explain the use of randc in System Verilog.

Answer: randc is used to randomize variables with constraints but in a complementary distribution.

randc int data;
constraint valid_data { data > 0; }

Reference: System Verilog IEEE Standard 1800-2017


64. What is the purpose of sequence_item in System Verilog?

Answer: sequence_item is a base class for creating items to be used in sequences for verification.

class my_sequence_item;
   int addr;
   bit [7:0] data;
   // ...
endclass

Reference: UVM IEEE Standard 1800.2-2020


65. How do you use disable fork in System Verilog?

Answer: disable fork is used to terminate parallel threads created by a fork-join construct.

fork
   task1;
   task2;
join_any
   // Code after join_any executes when any thread completes
disable fork; // Terminate all remaining threads

Reference: System Verilog IEEE Standard 1800-2017


66. Explain the use of overload in System Verilog.

Answer: The overload keyword allows multiple tasks or functions with the same name but different argument lists in the same scope.

class my_class;
   function void my_function(int a);
      // ...
   endfunction

   function void my_function(int a, int b);
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


67. How do you handle multi-dimensional arrays in System Verilog?

Answer: Multi-dimensional arrays are declared by specifying multiple range dimensions.

logic [3:0][7:0] matrix;

// Accessing elements
matrix[2][5] = 8'hFF;

Reference: System Verilog IEEE Standard 1800-2017


68. Explain the concept of uvm_sequence in System Verilog.

Answer: uvm_sequence is a fundamental building block of the UVM (Universal Verification Methodology) framework used for stimulus generation in verification environments.

class my_sequence extends uvm_sequence;
   // Define sequence items and behavior here
endclass

Reference: UVM IEEE Standard 1800.2-2020


69. What is the purpose of wait and wait_order in System Verilog assertions?

Answer: wait specifies a condition that must eventually become true. wait_order defines the order in which properties should be checked.

property p1;
   @(posedge clk) a |-> ##1 b;
endproperty

property p2;
   @(posedge clk) ##1 a |-> b;
endproperty

assert property (p1) else $fatal("p1 failed");
assert property (p2) else $fatal("p2 failed");

Reference: System Verilog IEEE Standard 1800-2017


70. How do you use clocking events in System Verilog?

Answer: clocking events are used to synchronize signals with clock edges, enabling precise event modeling.

clocking my_clocking @(posedge clk);
   input a, b;
   output y;

   default input #1 output #1;

   // Define clocking events here
endclocking

Reference: System Verilog IEEE Standard 1800-2017


71. Explain the concept of mailbox in System Verilog.

Answer: A mailbox is a synchronization primitive used for communication between different processes or threads.

mailbox mb;

initial begin
   // Task 1
   mb.put(5);
end

initial begin
   // Task 2
   int data;
   mb.get(data);
end

Reference: System Verilog IEEE Standard 1800-2017


72. What is the purpose of initial and final blocks in System Verilog?

Answer: initial blocks define behavior at time 0 or for simulation initialization. final blocks define cleanup or summary actions at the end of simulation.

initial begin
   // Initialization code
end

final begin
   // Cleanup code
end

Reference: System Verilog IEEE Standard 1800-2017


73. How do you use disable and # (delay) in System Verilog?

Answer: disable halts execution at a specific point. # introduces a delay in simulation.

initial begin
   #10; // Wait for 10 time units
   disable my_task; // Halt execution of task 'my_task'
end

Reference: System Verilog IEEE Standard 1800-2017


74. Explain the use of randc in System Verilog.

Answer: randc is used to randomize variables with constraints but in a complementary distribution.

randc int data;
constraint valid_data { data > 0; }

Reference: System Verilog IEEE Standard 1800-2017


75. What is the purpose of sequence_item in System Verilog?

Answer: sequence_item is a base class for creating items to be used in sequences for verification.

class my_sequence_item;
   int addr;
   bit [7:0] data;
   // ...
endclass

Reference: UVM IEEE Standard 1800.2-2020


76. How do you use disable fork in System Verilog?

Answer: disable fork is used to terminate parallel threads created by a fork-join construct.

fork
   task1;
   task2;
join_any
   // Code after join_any executes when any thread completes
disable fork; // Terminate all remaining threads

Reference: System Verilog IEEE Standard 1800-2017


77. Explain the use of overload in System Verilog.

Answer: The overload keyword allows multiple tasks or functions with the same name but different argument lists in the same scope.

class my_class;
   function void my_function(int a);
      // ...
   endfunction

   function void my_function(int a, int b);
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


78. How do you handle multi-dimensional arrays in System Verilog?

Answer: Multi-dimensional arrays are declared by specifying multiple range dimensions.

logic [3:0][7:0] matrix;

// Accessing elements
matrix[2][5] = 8'hFF;

Reference: System Verilog IEEE Standard 1800-2017


79. Explain the concept of uvm_sequence in System Verilog.

Answer: uvm_sequence is a fundamental building block of the UVM (Universal Verification Methodology) framework used for stimulus generation in verification environments.

class my_sequence extends uvm_sequence;
   // Define sequence items and behavior here
endclass

Reference: UVM IEEE Standard 1800.2-2020


80. What is the purpose of wait and wait_order in System Verilog assertions?

Answer: wait specifies a condition that must eventually become true. wait_order defines the order in which properties should be checked.

property p1;
   @(posedge clk) a |-> ##1 b;
endproperty

property p2;
   @(posedge clk) ##1 a |-> b;
endproperty

assert property (p1) else $fatal("p1 failed");
assert property (p2) else $fatal("p2 failed");

Reference: System Verilog IEEE Standard 1800-2017


81. How do you use clocking events in System Verilog?

Answer: clocking events are used to synchronize signals with clock edges, enabling precise event modeling.

clocking my_clocking @(posedge clk);
   input a, b;
   output y;

   default input #1 output #1;

   // Define clocking events here
endclocking

Reference: System Verilog IEEE Standard 1800-2017


82. Explain the concept of mailbox in System Verilog.

Answer: A mailbox is a synchronization primitive used for communication between different processes or threads.

mailbox mb;

initial begin
   // Task 1
   mb.put(5);
end

initial begin
   // Task 2
   int data;
   mb.get(data);
end

Reference: System Verilog IEEE Standard 1800-2017


83. What is the purpose of initial and final blocks in System Verilog?

Answer: initial blocks define behavior at time 0 or for simulation initialization. final blocks define cleanup or summary actions at the end of simulation.

initial begin
   // Initialization code
end

final begin
   // Cleanup code
end

Reference: System Verilog IEEE Standard 1800-2017


84. How do you use disable and # (delay) in System Verilog?

Answer: disable halts execution at a specific point. # introduces a delay in simulation.

initial begin
   #10; // Wait for 10 time units
   disable my_task; // Halt execution of task 'my_task'
end

Reference: System Verilog IEEE Standard 1800-2017


85. Explain the use of randc in System Verilog.

Answer: randc is used to randomize variables with constraints but in a complementary distribution.

randc int data;
constraint valid_data { data > 0; }

Reference: System Verilog IEEE Standard 1800-2017


86. What is the purpose of sequence_item in System Verilog?

Answer: sequence_item is a base class for creating items to be used in sequences for verification.

class my_sequence_item;
   int addr;
   bit [7:0] data;
   // ...
endclass

Reference: UVM IEEE Standard 1800.2-2020


87. How do you use disable fork in System Verilog?

Answer: disable fork is used to terminate parallel threads created by a fork-join construct.

fork
   task1;
   task2;
join_any
   // Code after join_any executes when any thread completes
disable fork; // Terminate all remaining threads

Reference: System Verilog IEEE Standard 1800-2017


88. Explain the use of overload in System Verilog.

Answer: The overload keyword allows multiple tasks or functions with the same name but different argument lists in the same scope.

class my_class;
   function void my_function(int a);
      // ...
   endfunction

   function void my_function(int a, int b);
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


89. How do you handle multi-dimensional arrays in System Verilog?

Answer: Multi-dimensional arrays are declared by specifying multiple range dimensions.

logic [3:0][7:0] matrix;

// Accessing elements
matrix[2][5] = 8'hFF;

Reference: System Verilog IEEE Standard 1800-2017


90. Explain the concept of uvm_sequence in System Verilog.

Answer: uvm_sequence is a fundamental building block of the UVM (Universal Verification Methodology) framework used for stimulus generation in verification environments.

class my_sequence extends uvm_sequence;
   // Define sequence items and behavior here
endclass

Reference: UVM IEEE Standard 1800.2-2020


91. What is the purpose of wait and wait_order in System Verilog assertions?

Answer: wait specifies a condition that must eventually become true. wait_order defines the order in which properties should be checked.

property p1;
   @(posedge clk) a |-> ##1 b;
endproperty

property p2;
   @(posedge clk) ##1 a |-> b;
endproperty

assert property (p1) else $fatal("p1 failed");
assert property (p2) else $fatal("p2 failed");

Reference: System Verilog IEEE Standard 1800-2017


92. How do you use clocking events in System Verilog?

Answer: clocking events are used to synchronize signals with clock edges, enabling precise event modeling.

clocking my_clocking @(posedge clk);
   input a, b;
   output y;

   default input #1 output #1;

   // Define clocking events here
endclocking

Reference: System Verilog IEEE Standard 1800-2017


93. Explain the concept of mailbox in System Verilog.

Answer: A mailbox is a synchronization primitive used for communication between different processes or threads.

mailbox mb;

initial begin
   // Task 1
   mb.put(5);
end

initial begin
   // Task 2
   int data;
   mb.get(data);
end

Reference: System Verilog IEEE Standard 1800-2017


94. What is the purpose of initial and final blocks in System Verilog?

Answer: initial blocks define behavior at time 0 or for simulation initialization. final blocks define cleanup or summary actions at the end of simulation.

initial begin
   // Initialization code
end

final begin
   // Cleanup code
end

Reference: System Verilog IEEE Standard 1800-2017


95. How do you use disable and # (delay) in System Verilog?

Answer: disable halts execution at a specific point. # introduces a delay in simulation.

initial begin
   #10; // Wait for 10 time units
   disable my_task; // Halt execution of task 'my_task'
end

Reference: System Verilog IEEE Standard 1800-2017


96. Explain the use of randc in System Verilog.

Answer: randc is used to randomize variables with constraints but in a complementary distribution.

randc int data;
constraint valid_data { data > 0; }

Reference: System Verilog IEEE Standard 1800-2017


97. What is the purpose of sequence_item in System Verilog?

Answer: sequence_item is a base class for creating items to be used in sequences for verification.

class my_sequence_item;
   int addr;
   bit [7:0] data;
   // ...
endclass

Reference: UVM IEEE Standard 1800.2-2020


98. How do you use disable fork in System Verilog?

Answer: disable fork is used to terminate parallel threads created by a fork-join construct.

fork
   task1;
   task2;
join_any
   // Code after join_any executes when any thread completes
disable fork; // Terminate all remaining threads

Reference: System Verilog IEEE Standard 1800-2017


99. Explain the use of overload in System Verilog.

Answer: The overload keyword allows multiple tasks or functions with the same name but different argument lists in the same scope.

class my_class;
   function void my_function(int a);
      // ...
   endfunction

   function void my_function(int a, int b);
      // ...
   endfunction
endclass

Reference: System Verilog IEEE Standard 1800-2017


100. How do you handle multi-dimensional arrays in System Verilog?

Answer: Multi-dimensional arrays are declared by specifying multiple range dimensions.

logic [3:0][7:0] matrix;

// Accessing elements
matrix[2][5] = 8'hFF;

Reference: System Verilog IEEE Standard 1800-2017