irq_pio.arm

ARM入门的好帮手.包含了从简单到相对较复杂的程序.

;------------------------------------------------------------------------------
;-         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          : irq_pio.arm
;- Object               : Assembler PIO Controller Interrupt Handler.
;-
;- 1.0 27/03/01 JPP     : Creation
;------------------------------------------------------------------------------

            AREA        Irq, CODE, READONLY, INTERWORK

            INCLUDE     ../../periph/aic/irq.mac
            INCLUDE     ../../periph/pio/pio.inc
	    
;------------------------------------------------------------------------------
;- Function             : pio_asm_irq_handler
;- Treatments           : Parallel IO Controller Interrupt Handler.
;- Called Functions     : pioa_irq_handler
;- Called Macros        : IRQ_ENTRY, IRQ_EXIT
;------------------------------------------------------------------------------
            IMPORT      pio_c_irq_handler
            EXPORT      pio_asm_irq_handler
pio_asm_irq_handler

;- Manage Exception Entry
        IRQ_ENTRY
;- Call the PIO Interrupt C handler
            ldr         r0, =pio_c_irq_handler
            mov         r14, pc
            bx          r0
;- Manage Exception Exit	    
	    b		exit_irq

;------------------------------------------------------------------------------
;- Function             : irq0_asm_irq_handler
;- Treatments           : IRQ0 IO Controller Interrupt Handler.
;- Called Functions     : at91_IRQ0_handler
;- Called Macros        : IRQ_ENTRY, IRQ_EXIT
;------------------------------------------------------------------------------
            EXPORT      irq0_asm_irq_handler
            IMPORT      at91_IRQ0_handler
irq0_asm_irq_handler

;- Manage Exception Entry
        IRQ_ENTRY
;- Call the PIO Interrupt C handler
            ldr         r0, =at91_IRQ0_handler
            mov         r14, pc
            bx          r0
;- Manage Exception Exit	    
	    b		exit_irq

;------------------------------------------------------------------------------
;- Function             : sw_asm_irq_handler
;- Treatments           : software Controller Interrupt Handler.
;- Called Functions     : aic_sotfware_interrupt
;- Called Macros        : IRQ_ENTRY, IRQ_EXIT
;------------------------------------------------------------------------------
            EXPORT      sw_asm_irq_handler
            IMPORT      aic_sotfware_interrupt
sw_asm_irq_handler

;- Manage Exception Entry
        IRQ_ENTRY
;- Call the PIO Interrupt C handler
            ldr         r0, =aic_sotfware_interrupt
            mov         r14, pc
            bx          r0
;- Irq exit 
exit_irq
;- Manage Exception Exit
            IRQ_EXIT
	    
;------------------------------------------------------------------------------
;- Function             : asm_fiq_init_handler
;- Treatments           : FIQ Init register.
;- Called Functions     : none
;- Called Macros        : IRQ_ENTRY, IRQ_EXIT
;------------------------------------------------------------------------------
           EXPORT      asm_fiq_init_handler

asm_fiq_init_handler

;- Adjust and save LR_irq in IRQ stack
            sub         r14, r14, #4
            stmfd       sp!, {r14}
            ldr         r12, =AIC_BASE
;- De-assert the NIRQ and clear the source in Protect Mode
            str         r12, [r12, #AIC_IVR]
;- No Mark the End of Interrupt on the AIC

;- Restore adjusted  LR_irq from IRQ stack directly in the PC
            ldmia       sp!, {pc}^

;------------------------------------------------------------------------------
;- Function             : asm_fiq_handler
;- Treatments           : software Controller Interrupt Handler.
;- Called Functions     : aic_sotfware_interrupt
;- Called Macros        : IRQ_ENTRY, IRQ_EXIT
;------------------------------------------------------------------------------
           EXPORT      asm_fiq_handler
           IMPORT      FIQ_handler
            
;- Adjust and save LR_fiq in FIQ stack
asm_fiq_handler
		
;- 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
            str         r12, [r12, #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, #F_BIT
            orr         r0, r0, #ARM_MODE_SYS
            msr         CPSR_c, r0			; Swap in SYS mode
            stmfd       sp!, { r1-r3, r12, r14}

;- Call the Interrupt C handler
            ldr		r0, =FIQ_handler
            mov         r14, pc
            bx          r0           

;- Restore scratch/used registers and LR from User Stack
            ldmia       sp!, { r1-r3, r12, r14}
;- Disable Interrupt and switch back in IRQ mode
            mrs         r0, CPSR
            bic         r0, r0, #ARM_MODE_SYS
            orr         r0, r0, #F_BIT:OR:ARM_MODE_FIQ
            msr         CPSR_c, r0			; Swap in FIQ mode

;- No Mark the End of Interrupt on the AIC

;- 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}^

            END