S3C2440 key interrupt mode assembly code

SRCPND EQU 0X4A000000
INTMSK EQU 0X4A000008
INTPND EQU 0X4A000010
EINTMASK EQU 0X560000A4
EINTPEND EQU 0X560000A8
EXTINT1 EQU 0X5600008C
EXTINT2 EQU 0X56000090
INTMOD EQU 0X4A000004

AREA INT_KEY,CODE,READONLY
ENTRY
CODE32
ResetEntry
b Reset
; //0x04: vector address of undefined instruction abort mode
HandleUndef
b HandleUndef
; //0x08: vector address of management mode, enter this mode through SWI instruction
HandleSWI
b HandleSWI
; //0x0c: vector address of exception caused by instruction prefetch termination
HandlePrefetchAbort
b HandlePrefetchAbort
; //0x10: vector address of exception caused by data access termination
HandleDataAbort
b HandleDataAbort
; //0x14: reserved
HandleNotUsed
b HandleNotUsed
; //0x18: vector address of interrupt mode
b HandleIRQ
; //0x1c: vector address of fast interrupt mode
HandleFIQ
b HandleFIQ
Reset
BL Disable_Watch_Dog
msr cpsr_c, #0xd2 ;// Enter interrupt mode
ldr sp, =3072 ;// Set interrupt mode stack pointer

msr cpsr_c, #0xdf ;// Enter system mode
;// Set system mode stack pointer,
;// Actually, after reset, the CPU is in system mode,

msr cpsr_c, #0x5f ;// Set I-bit=0, open IRQ interrupt

BL Main
halt_loop
B halt_loop
Disable_Watch_Dog ;// Disable watchdog, otherwise it will restart all the time
LDR R0,=0x53000000
MOV R1,#0x0
STR R1,[R0]
MOV PC, lr ;// Return to
Main
BL LED_Init
BL KEY_Init
BL INT_Init

B MAIN_LOOP
MOV PC,LR
MAIN_LOOP
B MAIN_LOOP
LED_Init
LDR R0,=0x56000010
MOV R1,#0x00015400
STR R1,[R0]

LDR R0,=0x56000014
MOV R1,#0x000001E0
STR R1,[R0]

MOV PC,LR
KEY_Init
LDR R0,=0x56000060
LDR R1,=0x80A882 ;//Set GPG0 as extended function
STR R1,[R0]
MOV PC,LR
INT_Init
MOV r1,#0x20
LDR r0,=SRCPND
STR r1,[r0]
LDR R1,=INTMSK
LDR R0,=0XFFC0
STR R0,[R1]
LDR R1,=EXTINT1
LDR R0,=0X22202002
STR R0,[R1]
LDR R1,=EXTINT2
LDR R0,=0X2000
STR R0,[R1]
LDR R1,=EINTMASK;//11110111000101101111111
LDR R0,=0XF716FF
STR R0,[R1]
LDR R1,=INTMOD
LDR R0,=0X0
STR R0,[R1]
MOV PC,LR
HandleIRQ
SUB LR,LR,#4 ;//Calculate the return address
STMDB SP!,{R0-R12,LR} ;//Save the used registers. At this time, sp is the sp of interrupt mode. Push it on the stack

LDR LR,=INT_RETURN ;//ISR return address
LDR PC,=EINT_HANDLE ;//Call interrupt service function
INT_RETURN
LDMIA SP!,{R0-R12,PC}^ ;//Interrupt return, ^ means copy the value of spsr to cpsr, pop the stack
EINT_HANDLE
NOP
LOOP
LDR R1,=EINTPEND
LDR R2,[R1]

LDR R3,=0XFFFFF;//Clear interrupt
STR R3,[R1]

LDR R1,=SRCPND
LDR R3,=0X3F
STR R3,[R1]

LDR R1,=INTPND
LDR R3,=0X3F
STR R3,[R1]
SWITCH
LDR R0,=0x56000014
CASE_8
TST R2,#0X100
BEQ CASE_11
LDR R1,=0X1C0
STR R1,[R0]
B SWITCH_END
CASE_11
TST R2,#0X800
BEQ CASE_13
LDR R1,=0X1A0
STR R1,[R0]
B SWITCH_END CASE_13 TST R2, #0X2000 BEQ CASE_14 LDR R1,=0X160 STR R1,[R0] B SWITCH_END
CASE_14 TST R2,#0X4000 BEQ CASE_15 LDR R1,=0X0E0 STR R1,[R0] B SWITCH_END CASE_15 TST R2,#0X8000 BEQ CASE_19 LDR R1,=0X000 STR R1,[R0] B SWITCH_END CASE_19 TST R2,#0X80000 BEQ DEFAULT LDR R1,=0X1E0 STR R1,[R0] B SWITCH_END























DEFAULT
LDR R1,=0X1E0
STR R1,[R0]
SWITCH_END
NOP
MOV PC,LR
END