at91sam9260 data abort

I am porting freeRTOS for AT91SAM9260.Now i encount a problem.

In my portAMS.s
I am using keil+jlink debug the program into SDRAM.
AT91C_BASE_AIC EQU 0xfffff000
AIC_EOICR EQU 0x130
 vPreemptiveTick

        PRESERVE8

        portSAVE_CONTEXT                                        ; Save the context of the current task.

        LDR R0, =vTaskIncrementTick                     ; Increment the tick count.
        MOV LR, PC                                                      ; This may make a delayed task ready
        BX R0                                                           ; to run.

        LDR R0, =vTaskSwitchContext                     ; Find the highest priority task that
        MOV LR, PC                                                      ; is ready to run.
         LDR LR, =AT91C_BASE_AIC ;acknowlege the interrupt
         STR LR, [R14, #AIC_EOICR];

        portRESTORE_CONTEXT                                     ; Restore the context of the highest
                                                                                ; priority task that is ready to run.
        END

The code Acknowlege the interrupt causes data abort.

Please help me.

Data abort,but the R14's value is 20002f64.
I don't understand.
This address is in SDARAM controller memory map.It shouldn't happen.