www.pudn.com > EBD9200EMAC.rar > asm_isr.s
;------------------------------------------------------------------------------
;- ATMEL Microcontroller Software Support - ROUSSET -
;------------------------------------------------------------------------------
; The software is delivered "AS IS" without warranty or condition of any
; kind, either express, implied or statutory. This includes without
; limitation any warranty or condition with respect to merchantability or
; fitness for any particular purpose, or against the infringements of
; intellectual property rights of others.
;-----------------------------------------------------------------------------
;- File source : it_handler.s
;- Object : Example of IT handler calling a C function
;- Compilation flag : None
;-
;- 1.0 16/03/01 ODi, : Creation ARM ADS
;------------------------------------------------------------------------------
AREA itHandler, CODE, READONLY
;------------------------------------------------------------------------------
;- LISR vector handler for system peripherals
;--------------------------------------------
;- This macro save the context, call the LISR dispatch routine, and restore
;- the context
;------------------------------------------------------------------------------
INCLUDE AT91RM9200.inc
;--------------------------------
;- ARM Core Mode and Status Bits
;--------------------------------
ARM_MODE_USER EQU 0x10
ARM_MODE_FIQ EQU 0x11
ARM_MODE_IRQ EQU 0x12
ARM_MODE_SVC EQU 0x13
ARM_MODE_ABORT EQU 0x17
ARM_MODE_UNDEF EQU 0x1B
ARM_MODE_SYS EQU 0x1F
I_BIT EQU 0x80
F_BIT EQU 0x40
T_BIT EQU 0x20
;------------------------------------------------------------------------------
;- IRQ Entry
;-----------
;------------------------------------------------------------------------------
MACRO
IRQ_ENTRY $reg
;- Adjust and save LR_irq in IRQ stack
sub r14, r14, #4
stmfd sp!, {r14}
;- Write in the IVR to support Protect Mode
;- No effect in Normal Mode
;- De-assert the NIRQ and clear the source in Protect Mode
ldr r14, =AT91C_BASE_AIC
str r14, [r14, #AIC_IVR]
;- Save SPSR and r0 in IRQ stack
mrs r14, SPSR
stmfd sp!, {r0, r14}
;- Enable Interrupt and Switch in SYS Mode
mrs r0, CPSR
bic r0, r0, #I_BIT
orr r0, r0, #ARM_MODE_SYS
msr CPSR_c, r0
;- Save scratch/used registers and LR in User Stack
IF "$reg" = ""
stmfd sp!, { r1-r3, r12, r14}
ELSE
stmfd sp!, { r1-r3, $reg, r12, r14}
ENDIF
MEND
;------------------------------------------------------------------------------
;- IRQ Exit
; ---------
;------------------------------------------------------------------------------
MACRO
IRQ_EXIT $reg
;- Restore scratch/used registers and LR from User Stack
IF "$reg" = ""
ldmia sp!, { r1-r3, r12, r14}
ELSE
ldmia sp!, { r1-r3, $reg, r12, r14}
ENDIF
;- Disable Interrupt and switch back in IRQ mode
mrs r0, CPSR
bic r0, r0, #ARM_MODE_SYS
orr r0, r0, #I_BIT:OR:ARM_MODE_IRQ
msr CPSR_c, r0
;- Mark the End of Interrupt on the AIC
ldr r0, =AT91C_BASE_AIC
str r0, [r0, #AIC_EOICR]
;- Restore SPSR_irq and r0 from IRQ stack
ldmia sp!, {r0, r14}
msr SPSR_cxsf, r14
;- Restore adjusted LR_irq from IRQ stack directly in the PC
ldmia sp!, {pc}^
MEND
;------------------------------------------------------------------------------
; AT91F_ST_ASM_HANDLER
; ---------------------
; Handler called by the AIC
;
; Save context
; Call C handler
; Restore context
;------------------------------------------------------------------------------
EXPORT AT91F_ST_ASM_HANDLER
IMPORT AT91F_ST_HANDLER
AT91F_ST_ASM_HANDLER
IRQ_ENTRY
ldr r1, =AT91F_ST_HANDLER
mov r14, pc
bx r1
IRQ_EXIT
END