Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Scheda Tecnica
Codici prodotto
AT91SAM9N12-EK
Programmer’s Model
2-20
Copyright © 2001-2003 ARM Limited. All rights reserved.
ARM DDI0198D
Table 2-16 shows the encodings used for the status field in the FSR, and if the Domain
field contains valid information. See Fault address and fault status registers on
page 3-21 for details of MMU aborts.
field contains valid information. See Fault address and fault status registers on
page 3-21 for details of MMU aborts.
2.3.7
Fault Address Register c6
Register c6 accesses the Fault Address Register (FAR). The FAR contains the Modified
Virtual Address of the access being attempted when a Data Abort occurred. The FAR is
only updated for Data Aborts, not for Prefetch Aborts. The FAR is updated for
alignment faults, and external aborts that occur while the MMU is disabled.
Virtual Address of the access being attempted when a Data Abort occurred. The FAR is
only updated for Data Aborts, not for Prefetch Aborts. The FAR is updated for
alignment faults, and external aborts that occur while the MMU is disabled.
You can use the following instructions to access the FAR:
MRC p15, 0, <Rd>, c6, c0, 0 ; read FAR
MCR p15, 0, <Rd>, c6, c0, 0 ; write FAR
MCR p15, 0, <Rd>, c6, c0, 0 ; write FAR
Writing c6 sets the FAR to the value of the data written. This is useful for a debugger to
restore the value of the FAR to a previous state.
restore the value of the FAR to a previous state.
The CRm and Opcode_2 fields Should Be Zero when reading or writing CP15 c6.
2.3.8
Cache Operations Register c7
Register c7 controls the caches and the write buffer. The function of each cache
operation is selected by the Opcode_2 and CRm fields in the MCR instruction used to
write to CP15 c7. Writing other Opcode_2 or CRm values is Unpredictable.
operation is selected by the Opcode_2 and CRm fields in the MCR instruction used to
write to CP15 c7. Writing other Opcode_2 or CRm values is Unpredictable.
Table 2-16 FSR status field encoding
Priority
Source
Size
Status
Domain
Highest
Alignment
-
b00x1
Invalid
External abort on translation
First level
Second level
Second level
b1100
b1110
b1110
Invalid
Valid
Valid
Translation
Section
Page
Page
b0101
b0111
b0111
Invalid
Valid
Valid
Domain
Section
Page
Page
b1001
b1011
b1011
Valid
Valid
Valid
Permission
Section
Page
Page
b1101
b1111
b1111
Valid
Valid
Valid
Lowest
External abort
Section or page
b10x0
Invalid