Creating a SystemVerilog Module that Stores Date and Time

Now that we have a basic structure in place, let's add functionality to manipulate the date and time. We'll create three functions: `inc_second`, `inc_minute`, and `inc_hour` to increment the second, minute, and hour components, respectively.

function void inc_second(ref datetime dt);
  dt.second++;
  if (dt.second == 60) begin
    dt.second = 0;
    inc_minute(dt);
  end
endfunction

function void inc_minute(ref datetime dt);
  dt.minute++;
  if (dt.minute == 60) begin
    dt.minute = 0;
    inc_hour(dt);
  end
endfunction

function void inc_hour(ref datetime dt);
  dt.hour++;
  if (dt.hour == 24) begin
    dt.hour = 0;
    // Update day, month, and year if necessary
  end
endfunction

In these functions, we've used the `ref` keyword to pass the `datetime` struct by reference, allowing us to modify its components directly. We've also added logic to handle rollbacks when the second, minute, or hour components reach their maximum values.

Leap Year and DST Handling

To account for leap years and DST adjustments, we'll add additional logic to our `inc_day` function.

function void inc_day(ref datetime dt);
  dt.day++;
  if (dt.day > days_in_month(dt.month, dt.year)) begin
    dt.day = 1;
    inc_month(dt);
  end
endfunction

function int days_in_month(int month, int year);
  case (month)
    1, 3, 5, 7, 8, 10, 12: return 31;
    2: begin
      if (is_leap_year(year)) return 29;
      else return 28;
    end
    default: return 30;
  endcase
endfunction

function bit is_leap_year(int year);
  return (year % 4 == 0 && year % 100 != 0) || year % 400 == 0;
endfunction

In this code snippet, we've added a `days_in_month` function to determine the number of days in a given month, taking into account leap years. We've also added an `is_leap_year` function to check if a year is a leap year.

Using the Datetime Module

Now that we have a fully functional `datetime_module`, let's see how to use it in a simple design.

module top (
  input logic clk,
  input logic reset
);

datetime dt_in, dt_out;

datetime_module datetime_inst (
  .clk(clk),
  .reset(reset),
  .dt_in(dt_in),
  .dt_out(dt_out)
);

initial begin
  dt_in.year = 2022;
  dt_in.month = 6;
  dt_in.day = 15;
  dt_in.hour = 12;
  dt_in.minute = 0;
  dt_in.second = 0;
end

always @(posedge clk) begin
  dt_in.second++;
  datetime_inst.dt_in = dt_in;
end

endmodule

In this example, we've instantiated the `datetime_module` and connected it to a clock signal and a reset signal. We've also defined an initial value for the `datetime` struct and increment the second component on each clock cycle.

Conclusion

In this article, we've explored how to create a SystemVerilog module that stores and manipulates date and time. We've defined a `datetime` struct to hold the date and time components, and a `datetime_module` module to initialize, reset, and manipulate these components. We've also added functionality to handle leap years and DST adjustments.

This module can be used in a variety of digital designs, from scheduling tasks to tracking events. By following the instructions and explanations provided in this article, you'll be able to create a reliable and efficient way to handle date and time in your designs.

Takeaway Points

• Create a SystemVerilog module to store and manipulate date and time.
• Use a structured approach with a `datetime` struct to hold the date and time components.
• Implement functions to increment the second, minute, and hour components.
• Account for leap years and DST adjustments.
• Use the module in a simple design to demonstrate its functionality.

FAQs

By following the instructions and explanations provided in this article, you'll be able to create a reliable and efficient SystemVerilog module that stores and manipulates date and time. Remember to account for leap years and DST adjustments, and use the module in a simple design to demonstrate its functionality.

Frequently Asked Questions

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