AREA	EXAMPLE4_8, CODE, READONLY
	ENTRY
RAM_ADDR	EQU	0x40000000	;change the address for your ARM
	LDR	R1,=RAM_ADDR	;R1 = RAM address 
AGAIN	MOV	R0,#0x55	;R0 = 0x55
	STRB	R0,[R1]		;send it to RAM 
	BL	DELAY  		;call delay (R14 = PC of next instruction)
	MOV	R0,#0xAA	;R0 = 0xAA
	STRB	R0,[R1]		;send it to RAM 
	BL	DELAY  		;call delay 
	B	AGAIN   	;keep doing it
	;--------------------DELAY SUBROUTINE
DELAY	LDR	R3,=5		;R3 =5, modify this value for different size delay 
L1	SUBS	R3,R3,#1	;R3 = R3 - 1 
	BNE	L1
	BX	LR		;return to caller
	;--------------------end of DELAY subroutine
	END		;notice the place for END directive