ATMEGA128-16AU SL383 Atmel, ATMEGA128-16AU SL383 Datasheet - Page 165

• Manufacturer Part Number: ATMEGA128-16AU SL383
• Manufacturer: Atmel

2467S–AVR–07/09
Note:
The following code examples show how to initialize the SPI as a Master and how to perform a
simple transmission. DDR_SPI in the examples must be replaced by the actual data direction
register controlling the SPI pins. DD_MOSI, DD_MISO and DD_SCK must be replaced by the
actual data direction bits for these pins. For example, if MOSI is placed on pin PB5, replace
DD_MOSI with DDB5 and DDR_SPI with DDRB.
Note:
Assembly Code Example
C Code Example
SPI_MasterInit:
SPI_MasterTransmit:
Wait_Transmit:
void SPI_MasterInit(void)
{
}
void SPI_MasterTransmit(char cData)
{
}
; Set MOSI and SCK output, all others input
ldi
out
; Enable SPI, Master, set clock rate fck/16
ldi
out
ret
; Start transmission of data (r16)
out
; Wait for transmission complete
sbis SPSR,SPIF
rjmp Wait_Transmit
ret
/* Set MOSI and SCK output, all others input */
DDR_SPI = (1<<DD_MOSI)|(1<<DD_SCK);
/* Enable SPI, Master, set clock rate fck/16 */
SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR0);
/* Start transmission */
SPDR = cData;
/* Wait for transmission complete */
while(!(SPSR & (1<<SPIF)))
1. See
1. See “About Code Examples” on page 9.
;
direction of the user defined SPI pins.
r17,(1<<DD_MOSI)|(1<<DD_SCK)
DDR_SPI,r17
r17,(1<<SPE)|(1<<MSTR)|(1<<SPR0)
SPCR,r17
SPDR,r16
“Alternate Functions of Port B” on page 74
(1)
(1)
for a detailed description of how to define the
ATmega128
165