Instructions for Use

1. Power Supply:

   • Connect Vcc to +5V and Vss to ground.
   • Ensure a stable power supply with appropriate decoupling capacitors (e.g., 100 nF and 10 μF) placed close to the power pins.

2. Clock Configuration:

   • Connect an external crystal or ceramic resonator to the XTAL1 and XTAL2 pins for the desired clock frequency.
   • Alternatively, use the internal oscillator by configuring the appropriate fuse bits.

3. Reset Circuit:

   • Connect a reset circuit to the RESET pin. A typical reset circuit includes a resistor and capacitor to provide a clean reset signal.
   • The reset pin should be held high for at least 100 μs after power-up to ensure proper initialization.

4. Programming:

   • Use an in-circuit programmer or an external programmer to write code to the flash memory.
   • Follow the programming specifications provided in the datasheet for correct voltage levels and timing requirements.

5. I/O Configuration:

   • Configure the I/O ports using the appropriate registers (e.g., DDRx for direction, PORTx for data).
   • Set the pull-up resistors as needed for input pins.

6. Interrupt Handling:

   • Enable interrupts by setting the corresponding bits in the interrupt control registers.
   • Write interrupt service routines (ISRs) to handle specific interrupt sources.

7. Low-Power Modes:

   • Enter idle mode by setting the appropriate bit in the status register.
   • Enter stop mode by setting the stop bit in the status register and ensuring all necessary peripherals are disabled.

8. Watchdog Timer:

   • Enable the watchdog timer by setting the appropriate bit in the watchdog control register.
   • Clear the watchdog timer periodically to prevent a reset.

9. Serial Communication:

   • Configure the UART settings (baud rate, data bits, parity, stop bits) using the appropriate registers.
   • Use the TXD and RXD pins for serial data transmission and reception.

10. Debugging:

    • Use an in-circuit debugger to step through code, set breakpoints, and inspect memory and registers.
    • Monitor the I/O pins and serial communication for correct operation.

For detailed information, refer to the official datasheet and application notes provided by the manufacturer.