The DFSR holds status information about the last data fault.  
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DFSR format when using the Short-descriptor translation table format
| Bits  | Name  | Function   | 
| [31:14]  | -  | Reserved.  | 
| [13]  | CM  | Cache maintenance fault.  | 
| [12]  | ExT  | External abort type.  | 
| [11]  | WnR  | Write not Read bit.  | 
| [10]  | FS[4]  | Fault status bits.  | 
| [9]  | LPAE  | Large Physical Address Extension.  | 
| [8]  | -  | Reserved.  | 
| [7:4]  | Domain  | The domain of the fault address.  | 
| [3:0]  | FS[3:0]  | Fault status bits.  | 
DFSR format when using the Long-descriptor translation table format
| Bits  | Name  | Function   | 
| [31:14]  | -  | Reserved.  | 
| [13]  | CM  | Cache maintenance fault.  | 
| [12]  | ExT  | External abort type.  | 
| [11]  | WnR  | Write not Read bit.  | 
| [10]  | -  | Reserved.  | 
| [9]  | LPAE  | Large Physical Address Extension.  | 
| [8:6]  | -  | Reserved.  | 
| [5:0]  | STATUS  | Fault status bits.  | 
Consider __get_DFSR and __set_DFSR to access this register.