TQ2440启动代码分析（二）

;=====================================================================

; Clock division test

; Assemble code, because VSYNC time is very short

;=====================================================================

EXPORT CLKDIV124

EXPORT CLKDIV144

CLKDIV124

ldr r0, = CLKDIVN

ldr r1, = 0x3 ; 0x3 = 1:2:4

str r1, [r0]

; wait until clock is stable

nop

nop

nop

nop

nop

ldr r0, = REFRESH

ldr r1, [r0]

bic r1, r1, #0xff

bic r1, r1, #(0x7<<8)

orr r1, r1, #0x470 ; REFCNT135

str r1, [r0]

nop

nop

nop

nop

nop

mov pc, lr

CLKDIV144

ldr r0, = CLKDIVN

ldr r1, = 0x4 ; 0x4 = 1:4:4

str r1, [r0]

; wait until clock is stable

nop

nop

nop

nop

nop

ldr r0, = REFRESH

ldr r1, [r0]

bic r1, r1, #0xff

bic r1, r1, #(0x7<<8)

orr r1, r1, #0x630 ; REFCNT675 - 1520

str r1, [r0]

nop

nop

nop

nop

nop

mov pc, lr

ALIGN;按照一定的规则对齐，^符号相当于伪指令MAP，用于定义一个结构化的内存表的首地址

AREA RamData, DATA, READWRITE

;

^ _ISR_STARTADDRESS ; _ISR_STARTADDRESS=0x33FF_FF00

HandleReset # 4

HandleUndef # 4

HandleSWI # 4

HandlePabort # 4

HandleDabort # 4

HandleReserved # 4

HandleIRQ # 4

HandleFIQ # 4

;Do not use the label IntVectorTable,

;The value of IntVectorTable is different with the address you think it may be.

;IntVectorTable

;@0x33FF_FF20

HandleEINT0 # 4

HandleEINT1 # 4

HandleEINT2 # 4

HandleEINT3 # 4

HandleEINT4_7 # 4

HandleEINT8_23 # 4

HandleCAM # 4 ; Added for 2440.

HandleBATFLT # 4

HandleTICK # 4

HandleWDT # 4

HandleTIMER0 # 4

HandleTIMER1 # 4

HandleTIMER2 # 4

HandleTIMER3 # 4

HandleTIMER4 # 4

HandleUART2 # 4

;@0x33FF_FF60

HandleLCD # 4

HandleDMA0 # 4

HandleDMA1 # 4

HandleDMA2 # 4

HandleDMA3 # 4

HandleMMC # 4

HandleSPI0 # 4

HandleUART1 # 4

HandleNFCON # 4 ; Added for 2440.

HandleUSBD # 4

HandleUSBH # 4

HandleIIC # 4

HandleUART0 # 4

HandleSPI1 # 4

HandleRTC # 4

HandleADC # 4

;@0x33FF_FFA0

END