Source Code:

    

      

      	;.INCLUDE "M32DEF.INC"
.equ	MOSI = 5
.equ	SCK = 7
.equ	SS = 4

	LDI	R17,0xFF			
	OUT	DDRA,R17

	LDI R17,(1<<MOSI)|(1<<SCK)|(1<<SS)
	OUT DDRB,R17			

	LDI R17,(1<<SPE)|(1<<MSTR)|(1<<SPR0)	
	OUT SPCR,R17				

Transmit:
	CBI PORTB,SS				
	LDI R17,'G'			
	OUT SPDR,R17		

Wait:
	SBIS SPSR,SPIF		
	RJMP Wait			
	IN	R18,SPDR
	OUT	PORTA,R18

	SBI PORTB,SS		

	RJMP Transmit