LPC2131/2132/2138 User Manual - mct.net

Philips Semiconductors Preliminary User Manual
ARM-based Microcontroller
;MSR spsr, r12 ;Restore SPSR from r12
;STMFD sp!, {r0}
;LDR r0, =VICBaseAddr
;STR r1, [r0,#VICVectAddrOffset] ;Acknowledge Non Vectored irq has finished
;LDMFD sp!, {r12,r14,r0} ;Restore registers
;SUBS pc, r14, #4 ;Return to the interrupted instruction
;user interrupt did not happen so call rm_irqhandler2. This handler
;is not aware of the VIC interrupt priority hardware so trick
;rm_irqhandler2 to return here
STMFD sp!, {ip,pc}
LDR pc, rm_irqhandler2
;rm_irqhandler2 returns here
MSR cpsr_c, #0x52 ;Disable irq, move to IRQ mode
MSR spsr, r12 ;Restore SPSR from r12
STMFD sp!, {r0}
LDR r0, =VICBaseAddr
STR r1, [r0,#VICVectAddrOffset] ;Acknowledge Non Vectored irq has finished
LDMFD sp!, {r12,r14,r0} ;Restore registers
SUBS pc, r14, #4 ;Return to the interrupted instruction
END
LPC2131/2132/2138
RealMonitor 262 November 22, 2004