w90n740init.s

ARM嵌入式应用开发典型实例配书光盘,希望对你有用！

	AREA SDRAM_INIT, CODE, READONLY
	ENTRY
;	LDR	r0,=module0
;	LDR	r0,=module1
 	LDR	r0,=module2
;	LDR	r0,=module3
	LDR	r1,=0xFFF01000
	LDMFD	r0,{r2-r7}
	STMIA	r1,{r2-r7}

;EXTIO Bank 0
	LDR	r0,=0x08003FFE
	LDR	r1,=0xFFF01018
	STR	r0,[r1]
;EXTIO Bank 1
	LDR	r0,=0x10003FFE
	LDR	r1,=0xFFF0101C
	STR	r0,[r1]
;EXTIO Bank 2
	LDR	r0,=0x20003FFE
	LDR	r1,=0xFFF01020
	STR	r0,[r1]
;EXTIO Bank 3
	LDR	r0,=0x40003FFE
	LDR	r1,=0xFFF01024
	STR	r0,[r1]

	; setting clock skew

    ; Check version number of W90N740 to set the clock skew
    LDR		r0, =0xFFF00000
    LDR		r0, [r0]
    LDR		r1, =0x0F000000
    ANDS	r0,r0,r1
    BEQ		version0
    LDR		r1, =0x01000000
    CMP		r0, r1
    BEQ		version1
    B		unknow_version
version0
	LDR		r0, =0x0FF007A
    B		update_clkskew
version1    
	LDR		r0, =0x0FF0039
    B		update_clkskew
update_clkskew
	LDR		r1, =0xFFF01F00
	STR		r0,[r1]		
unknow_version

	
	; check memory type
	LDR		r0,=0x0
	STR		r0,[r0]
	LDR		r0,=0x800
	LDR		r1,=0x12345678
	STR		r1,[r0]
	LDR		r0,=0x0
	LDR		r2,[r0]
	CMP		r1,r2
	BNE		%F0
	LDR		r0,=0xFFF01008
	LDR		r1,=0x00009062
	STR		r1,[r0]
	
0
	;check memory size
	LDR		r1,=0xFFF01008
	LDR		r1,[r1]
	LDR		r2,=0x00001062
	CMP		r1,r2
	LDRNE	r0,=0x800000  ;memory size
	LDREQ	r0,=0x400000 ;memorysize
	
	
	
	MOV		r0,#0x18
	SWI		0x123456
	
0	B	%0

module0
	DCD	0x000509c0
	DCD	0xfe000FF0
;	DCD	0x00009062 ; for W90N740 DEMO BOARD(with 1Mx16 width 32)
;	DCD	0x00000000
	DCD	0x00009041
	DCD	0x00409041
	DCD	0x00000292
	DCD	0x00000292
module1
	DCD	0x000509c0
	DCD	0xfe000FF0
	DCD	0x000090b5
	DCD	0x040090b5
	DCD	0x00000292
	DCD	0x00000292
module2
	DCD	0x000509c0
	DCD	0xfe000FF0
	DCD	0x000090e3
	DCD	0x010090e3
	DCD	0x00000292
	DCD	0x00000292
module3	
	DCD	0x000509c0
	DCD	0xfe000FF0
	DCD	0x000090ed
	DCD	0x040090ed
	DCD	0x00000292
	DCD	0x00000292	
	END