AT90PWM2 datasheet(198/365 Pages) ATMEL

198 / 365 page

198

AT90PWM2/3

4317B–AVR–02/05

The following simple USART initialization code examples show one assembly and one

C function that are equal in functionality. The examples assume asynchronous opera-

tion using polling (no interrupts enabled) and a fixed frame format. The baud rate is

given as a function parameter. For the assembly code, the baud rate parameter is

assumed to be stored in the r17:r16 Registers.

Note:

1. The example code assumes that the part specific header file is included.

For I/O Registers located in extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”,

and “SBI” instructions must be replaced with instructions that allow access to

extended I/O. Typically “LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and

“CBR”.

More advanced initialization routines can be made that include frame format as parame-

ters, disable 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

(1)

USART_Init:

; Set baud rate

out

UBRRH, r17

out

UBRRL, r16

; Set frame format: 8data, no parity & 2 stop bits

ldi

r16, (0<<UMSEL)|(0<<UPM0)|(1<<USBS)|(3<<UCSZ0)

out

UCSRC,r16

; Enable receiver and transmitter

ldi

r16, (1<<RXEN0)|(1<<TXEN0)

out

UCSRB,r16

ret

C Code Example(1)

void

USART_Init( unsigned int baud )

{

/* Set baud rate */

UBRRH = (unsigned char)(baud>>8);

UBRRL = (unsigned char)baud;

/* Set frame format: 8data, no parity & 2 stop bits */

UCSRC = (0<<UMSEL)|(0<<UPM0)|(1<<USBS)|(3<<UCSZ0);

/* Enable receiver and transmitter */

UCSRB = (1<<RXEN0)|(1<<TXEN0);

}

AT90PWM2 Datasheet(PDF) 198 Page - ATMEL Corporation

AT90PWM2 Datasheet(HTML) 198 Page - ATMEL Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL