Rainbow Electronics ATmega3290P_V User Manual

Page 155

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155

ATmega329/339/649/659

2552H–AVR–11/06

Note:

1. See “About Code Examples” on page 8.

SPI_MasterInit:

; Set MOSI and SCK output, all others input

ldi

r17,(1<

out

DDR_SPI,r17

; Enable SPI, Master, set clock rate fck/16

ldi

r17,(1<

out

SPCR,r17

ret

SPI_MasterTransmit:

; Start transmission of data (r16)

out

SPDR,r16

Wait_Transmit:

; Wait for transmission complete

sbis

SPSR,SPIF

rjmp

Wait_Transmit

ret

C Code Example

(1)

void

SPI_MasterInit(void)

{

/* Set MOSI and SCK output, all others input */

DDR_SPI = (1<

/* Enable SPI, Master, set clock rate fck/16 */

SPCR = (1<

}

void

SPI_MasterTransmit(char cData)

{

/* Start transmission */

SPDR = cData;

/* Wait for transmission complete */

while

(!(SPSR & (1<

;

}