44binit.s

arm的键盘程序 基本的知识 包含ARM和Thumb指令

    ;以下三段设置时钟控制寄存器
    
    ldr	r0,=LOCKTIME
    ldr	r1,=0xfff			
    str	r1,[r0]

    [ PLLONSTART
		ldr	r0,=PLLCON			;temporary setting of PLL
		ldr	r1,=((M_DIV<<12)+(P_DIV<<4)+S_DIV)
		str	r1,[r0]
    ]

    ldr	    r0,=CLKCON		 
    ldr	    r1,=0x7ff8	    	;All unit block CLK enable	
    str	    r1,[r0]
	
	;****************************************************
	;change BDMACON reset value for BDMA                *
	;****************************************************

    ldr     r0,=BDIDES0       
    ldr     r1,=0x40000000		;BDIDESn reset value should be 0x40000000	 
    str     r1,[r0]

    ldr     r0,=BDIDES1      
    ldr     r1,=0x40000000		;BDIDESn reset value should be 0x40000000	 
    str     r1,[r0]

    ;****************************************************
    ;设定存储器控制寄存器            					* 	
    ;****************************************************
    ldr	    r0,=SMRDATA
    ldmia   r0,{r1-r13}
    ldr	    r0,=0x01c80000		;BWSCON Address
    stmia   r0,{r1-r13}

    ;****************************************************
    ;初始化堆栈              							* 
    ;****************************************************
    ldr	    sp, =SVCStack		;复位后位SVC模式
    bl	    InitStacks

    ;****************************************************
    ;设置中断处理        								*
    ;****************************************************
    ldr	    r0,=HandleIRQ		;This routine is needed
    ldr	    r1,=IsrIRQ			;if there isn't 'subs pc,lr,#4' at 0x18, 0x1c
    str	    r1,[r0]

    ;****************************************************
    ;Copy and paste RW data/zero initialized data    	*
    ;****************************************************
    LDR	    r0, =|Image$$RO$$Limit|	; Get pointer to ROM data
    LDR	    r1, =|Image$$RW$$Base|	; and RAM copy
    LDR	    r3, =|Image$$ZI$$Base|	
	;Zero init base => top of initialised data
			
    CMP	    r0, r1	    		; Check that they are different
    BEQ	    %F1
0
    CMP	    r1, r3	    		; Copy init data
    LDRCC   r2, [r0], #4    	;--> LDRCC r2, [r0] + ADD r0, r0, #4
    STRCC   r2, [r1], #4   		;--> STRCC r2, [r1] + ADD r1, r1, #4
    BCC	    %B0
1
    LDR	    r1, =|Image$$ZI$$Limit| ; Top of zero init segment
    MOV	    r2, #0
2
    CMP	    r3, r1	    		;Zero init
    STRCC   r2, [r3], #4
    BCC	    %B2

    [ :LNOT:THUMBCODE
		bl	Main	    		;Don't use main() because ......
		b	.						
    ]

    [ THUMBCODE		    		;for start-up code for Thumb mode
		orr	lr,pc,#1
		bx	lr
		CODE16
		bl	Main	    	;Don't use main() because ......
		b	.
		CODE32
    ]

;****************************************************
;*	The function for initializing stack				*
;****************************************************
InitStacks
	;Don't use DRAM,such as stmfd,ldmfd......
	;SVCstack is initialized before
	;Under toolkit ver 2.50, 'msr cpsr,r1' can be used instead of 'msr cpsr_cxsf,r1'

    mrs	    r0,cpsr
    bic	    r0,r0,#MODEMASK
    orr	    r1,r0,#UNDEFMODE|NOINT
    msr	    cpsr_cxsf,r1			;UndefMode
    ldr	    sp,=UndefStack
	
    orr	    r1,r0,#ABORTMODE|NOINT
    msr	    cpsr_cxsf,r1 	    	;AbortMode
    ldr	    sp,=AbortStack

    orr	    r1,r0,#IRQMODE|NOINT
    msr	    cpsr_cxsf,r1 	    	;IRQMode
    ldr	    sp,=IRQStack
	
    orr	    r1,r0,#FIQMODE|NOINT
    msr	    cpsr_cxsf,r1 	    	;FIQMode
    ldr	    sp,=FIQStack

    bic	    r0,r0,#MODEMASK|NOINT
    orr	    r1,r0,#SVCMODE
    msr	    cpsr_cxsf,r1 	    	;SVCMode
    ldr	    sp,=SVCStack

	;USER mode is not initialized.
    mov	    pc,lr ;The LR register may be not valid for the mode changes.

;****************************************************
;*	The function for entering power down mode		*
;****************************************************
;void EnterPWDN(int CLKCON);
EnterPWDN
    mov	    r2,r0               ;r0=CLKCON
    ldr	    r0,=REFRESH		
    ldr	    r3,[r0]
    mov	    r1, r3
    orr	    r1, r1, #0x400000   ;self-refresh enable
    str	    r1, [r0]

    nop     ;Wait until self-refresh is issued. May not be needed.
    nop     ;If the other bus master holds the bus, ...
    nop	    ; mov r0, r0
    nop
    nop
    nop
    nop

;enter POWERDN mode
    ldr	    r0,=CLKCON
    str	    r2,[r0]

;wait until enter SL_IDLE,STOP mode and until wake-up
    mov	    r0,#0xff
0   subs    r0,r0,#1
    bne	    %B0

;exit from DRAM/SDRAM self refresh mode.
    ldr	    r0,=REFRESH
    str	    r3,[r0]
    mov	    pc,lr

    LTORG

SMRDATA DATA
;*****************************************************************
;* Memory configuration has to be optimized for best performance *
;* The following parameter is not optimized.                     *
;*****************************************************************

;*** memory access cycle parameter strategy ***
; 1) Even FP-DRAM, EDO setting has more late fetch point by half-clock
; 2) The memory settings,here, are made the safe parameters even at 66Mhz.
; 3) FP-DRAM Parameters:tRCD=3 for tRAC, tcas=2 for pad delay, tcp=2 for bus load.
; 4) DRAM refresh rate is for 40Mhz. 

    [ BUSWIDTH=16
		DCD 0x11111001	;Bank0=OM[1:0], Bank1~Bank7=16bit
    | ;BUSWIDTH=32
		DCD 0x22222220	;Bank0=OM[1:0], Bank1~Bank7=32bit
    ]
	DCD ((B0_Tacs<<13)+(B0_Tcos<<11)+(B0_Tacc<<8)+(B0_Tcoh<<6)+(B0_Tah<<4)+(B0_Tacp<<2)+(B0_PMC))	;GCS0
	DCD ((B1_Tacs<<13)+(B1_Tcos<<11)+(B1_Tacc<<8)+(B1_Tcoh<<6)+(B1_Tah<<4)+(B1_Tacp<<2)+(B1_PMC))	;GCS1 
	DCD ((B2_Tacs<<13)+(B2_Tcos<<11)+(B2_Tacc<<8)+(B2_Tcoh<<6)+(B2_Tah<<4)+(B2_Tacp<<2)+(B2_PMC))	;GCS2
	DCD ((B3_Tacs<<13)+(B3_Tcos<<11)+(B3_Tacc<<8)+(B3_Tcoh<<6)+(B3_Tah<<4)+(B3_Tacp<<2)+(B3_PMC))	;GCS3
	DCD ((B4_Tacs<<13)+(B4_Tcos<<11)+(B4_Tacc<<8)+(B4_Tcoh<<6)+(B4_Tah<<4)+(B4_Tacp<<2)+(B4_PMC))	;GCS4
	DCD ((B5_Tacs<<13)+(B5_Tcos<<11)+(B5_Tacc<<8)+(B5_Tcoh<<6)+(B5_Tah<<4)+(B5_Tacp<<2)+(B5_PMC))	;GCS5
	[ BDRAMTYPE="DRAM" 
	    DCD ((B6_MT<<15)+(B6_Trcd<<4)+(B6_Tcas<<3)+(B6_Tcp<<2)+(B6_CAN))	;GCS6 check the MT value in parameter.a
	    DCD ((B7_MT<<15)+(B7_Trcd<<4)+(B7_Tcas<<3)+(B7_Tcp<<2)+(B7_CAN))	;GCS7
	| ;"SDRAM"
		DCD ((B6_MT<<15)+(B6_Trcd<<2)+(B6_SCAN))	;GCS6
		DCD ((B7_MT<<15)+(B7_Trcd<<2)+(B7_SCAN))	;GCS7
	]
	DCD ((REFEN<<23)+(TREFMD<<22)+(Trp<<20)+(Trc<<18)+(Tchr<<16)+REFCNT)	;REFRESH RFEN=1, TREFMD=0, trp=3clk, trc=5clk, tchr=3clk,count=1019
	DCD 0x10			;SCLK power down mode, BANKSIZE 32M/32M
	DCD 0x20			;MRSR6 CL=2clk
	DCD 0x20			;MRSR7

	ALIGN

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;RW BEGIN;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	AREA RamData, DATA, READWRITE

	^	(_ISR_STARTADDRESS-0x500)
				
UserStack		#	256	;c1(c7)ffa00
SVCStack		#	256	;c1(c7)ffb00
UndefStack		#	256	;c1(c7)ffc00
AbortStack		#	256	;c1(c7)ffd00
IRQStack		#	256	;c1(c7)ffe00
FIQStack		#	0	;c1(c7)fff00


		^	_ISR_STARTADDRESS
HandleReset		#	4
HandleUndef		#	4
HandleSWI		#	4
HandlePabort	#	4
HandleDabort	#	4
HandleReserved	#	4
HandleIRQ		#	4
HandleFIQ		#	4

;Don't use the label 'IntVectorTable',
;because armasm.exe cann't recognize this label correctly.
;the value is different with an address you think it may be.
;IntVectorTable
HandleADC		#	4
HandleRTC		#	4
HandleUTXD1		#	4
HandleUTXD0		#	4
HandleSIO		#	4
HandleIIC		#	4
HandleURXD1		#	4
HandleURXD0		#	4
HandleTIMER5	#	4
HandleTIMER4	#	4
HandleTIMER3	#	4
HandleTIMER2	#	4
HandleTIMER1	#	4
HandleTIMER0	#	4
HandleUERR01	#	4
HandleWDT		#	4
HandleBDMA1		#	4
HandleBDMA0		#	4
HandleZDMA1		#	4
HandleZDMA0		#	4
HandleTICK		#	4
HandleEINT4567	#	4
HandleEINT3		#	4
HandleEINT2		#	4
HandleEINT1		#	4
HandleEINT0		#	4   ;0xc1(c7)fff84

		END