Where are reset and interrupt vectors located in ATmega328P?

Where are reset and interrupt vectors located in ATmega328P?

These interrupts and the separate Reset Vector each have a separate program vector located at the lowest addresses in the Flash program memory space. The complete list of vectors is shown in Table 11-6 “Reset and Interrupt Vectors in ATMega328P.

When is SREG I-bit set in ATmega328P?

The (8) SREG I-bit is automatically set when the reti instruction is executed (i.e., Interrupts enabled). When the AVR exits from an interrupt, it will always (9) return to the interrupted program and (10) execute one more instruction before any pending interrupt is served.

Why does USART RX interrupt not work as expected?

However, when I tried adding interrupt on USART_RX_vect, the program does not work as expected anymore. Below is my small program. The expected behavior of this program is everytime I press a button the LED should toggle its state, but also by default the LED will toggle its state every 500ms.

How often should an ATmega328P program toggle its state?

The expected behavior of this program is everytime I press a button the LED should toggle its state, but also by default the LED will toggle its state every 500ms. Right now, the LED toggles every 500ms but the moment I press a button on my machine keyboard to send data to the ATmega328p, the program stops (the led freezes on its last state).

When to clear the eifr flag in ATmega328P?

Alternatively, the flag can be cleared by writing a logical one to it. The EIFR register is within the I/O address range (0x00 to 0x1F) of the Set Bit in I/O Register (SBI) Instruction. This flag is always cleared when INT0 is configured as a level interrupt.

When does a pin change interrupt PCI2 trigger?

The pin change interrupt enable bit (PCIE 2:0) group the pin is assigned. Specifically, a pin change interrupt PCI2 will trigger if any enabled PCINT23..16 pin toggles. A pin change interrupt PCI1 will trigger if any enabled PCINT14..8 pin toggles.