ATmega325PA Atmel Corporation, ATmega325PA Datasheet - Page 176

• Manufacturer Part Number: ATmega325PA
• Manufacturer: Atmel Corporation

8285D–AVR–06/11
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P
Note:
More advanced initialization routines can be made that include frame format as parameters, dis-
able interrupts and so on. However, many applications use a fixed setting of the baud and
control registers, and for these types of applications the initialization code can be placed directly
in the main routine, or be combined with initialization code for other I/O modules.
Assembly Code Example
C Code Example
USART_Init:
#define FOSC 1843200// Clock Speed
#define BAUD 9600
#define MYUBRR FOSC/16/BAUD-1
void main( void )
{
}
void USART_Init( unsigned int ubrr)
{
}
; Set baud rate
sts
sts
; Enable receiver and transmitter
ldi
sts
; Set frame format: 8data, 2stop bit
ldi
sts
ret
...
USART_Init ( MYUBRR );
...
/* Set baud rate */
UBRRH0 = (unsigned char)(ubrr>>8);
UBRRL0 = (unsigned char)ubrr;
/* Enable receiver and transmitter */
UCSR0B = (1<<RXEN0)|(1<<TXEN0);
/* Set frame format: 8data, 2stop bit */
UCSRnC = (1<<USBS0)|(3<<UCSZ00);
1.
See ”About Code Examples” on page 9.
UBRR0H, r17
UBRR0L, r16
r16, (1<<RXEN0)|(1<<TXEN0)
UCSR0B,r16
r16, (1<<USBS0)|(3<<UCSZ00)
UCSR0C,r16
(1)
(1)
176