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Atmega162/v – Rainbow Electronics ATmega162V User Manual

Page 160

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160

ATmega162/V

2513E–AVR–09/03

The following code examples show how to initialize the SPI as a slave and how to per-
form a simple reception.

Note:

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

Assembly Code Example

(1)

SPI_SlaveInit:

; Set MISO output, all others input

ldi

r17,(1<

out

DDR_SPI,r17

; Enable SPI

ldi

r17,(1<

out

SPCR,r17

ret

SPI_SlaveReceive:

; Wait for reception complete

sbis

SPSR,SPIF

rjmp

SPI_SlaveReceive

; Read received data and return

in

r16,SPDR

ret

C Code Example

(1)

void SPI_SlaveInit(void)

{

/* Set MISO output, all others input */

DDR_SPI = (1<

/* Enable SPI */

SPCR = (1<

}

char SPI_SlaveReceive(void)

{

/* Wait for reception complete */

while(!(SPSR & (1<

;

/* Return data register */

return SPDR;

}