#include <Arduino.h>

void delay_1ms() {
  // 1 ms delay function using inline assembly
  asm volatile (
    "ldi r20, 21\n"        // Load 16 into r20 (outer loop counter)
    "outer_loop:\n"
    "ldi r19, 251\n"       // Load 256 into r19 (inner loop counter)
    "inner_loop:\n"
    "dec r19\n"            // Decrement r19
    "brne inner_loop\n"    // If r19 is not zero, branch to inner_loop
    "dec r20\n"            // Decrement r20
    "brne outer_loop\n"    // If r20 is not zero, branch to outer_loop
    "nop\n"                // No operation (to ensure exact delay)
  );
}

void delay_ms(uint16_t ms) {
  for (uint16_t i = 0; i < ms; i++) {
    delay_1ms();
  }
}

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  
  // Set all PORTB pins as output (if needed)
  DDRB = 0xFF;
}

void loop() {
  // Record starting time
  unsigned long t1 = millis();
  PORTB = 0x3f;
  PORTD = 0xF0;
  // Perform delay for 1000 ms
  delay_ms(1000);

  // Record ending time
  unsigned long t2 = millis();
  PORTB = 0x00;
  PORTD = 0x00;

  // Print the time taken by the task
  Serial.print("Time taken by the task: ");
  Serial.print(t2 - t1);
  Serial.println(" milliseconds");


  // Perform any other tasks or operations here
  // For example, toggling PORTB as in your original code

  
  // Delay for 1 second (1000 ms) between tasks
  delay_ms(1000);
}