watchdog verilog

Watchdog in Verilog is a circuit or module that monitors the system's operation and ensures it is functioning properly. It is commonly used in embedded systems to detect and recover from system failures or malfunctions.

The watchdog module typically consists of a timer and a reset signal. The timer counts down from a preset value, and if the timer reaches zero before being reset, it indicates a system fault, triggering a reset of the system.

Here's an example of a simple watchdog module in Verilog:

module watchdog(
  input wire clk,  // Clock input
  input wire enable,  // Enable signal
  output wire reset  // Reset signal
);

  reg [15:0] timer;  // Timer counter
  
  always @(posedge clk) begin
    if (enable) begin
      timer <= timer - 1;  // Decrement the timer on each clock cycle
      if (timer == 0) begin
        reset <= 1;  // Assert reset signal if timer reaches zero
      end
    end else begin
      timer <= 0;  // Reset the timer when disabled
      reset <= 0;  // Clear the reset signal
    end
  end

endmodule

In this example, the watchdog module takes in a clock signal (`clk`), an enable signal (`enable`), and outputs a reset signal (`reset`). The module uses an internal timer (`timer`) that decrements on each rising edge of the clock when the enable signal is active. If the timer reaches zero, it asserts the reset signal.

You can instantiate this module in your Verilog design and configure the timer duration according to your system requirements. Remember to connect the clock and enable signals appropriately.

Please note that this is just a basic implementation, and you may need to modify it based on your specific design needs and requirements.