Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Data Sheet
Product codes
AT91SAM9N12-EK
CP15 Test and Debug Registers
ARM DDI0198D
Copyright © 2001-2003 ARM Limited. All rights reserved.
B-7
2.
Use the following MMU test operation instructions to access the MVA tag:
MRC p15, 4/5, <Rd>, c15, c2, 0 ; read tag in main TLB
MCR p15, 4/5, <Rd>, c15, c3, 0 ; write tag in main TLB
The Rd register contains the read or write data as Figure B-3 shows.
Figure B-3 Rd format for accessing MVA tag of main or lockdown TLB entry
Table B-5 describes the MVA tag access bit fields in the Rd register.
3.
Use the following MMU Test Register instructions to access the PA and access
permission data:
permission data:
MRC p15, 4/5, <Rd>, c15, c4, 0 ; read PA and access permission data
[30:15]
-
Should Be Zero.
[14:10]
Indexed entry
Indexed entry in main TLB.
[9:0]
-
Should Be Zero.
Table B-4 Encoding of the main TLB entry-select bit fields
Bit
Name
Definition
0
MVA tag
SBZ
4 3
9
5
10
31
V
Size of
entry
Table B-5 Encoding of the TLB MVA tag bit fields
Bit
Name
Definition
[31:10]
MVA tag
Modified virtual address.
[9:5]
-
Should Be Zero.
[4]
V
Valid bit.
[3:0]
Size of entry
Size of entry:
b1011 = 1MB section
b0111 = 64KB page
b0101 = 16KB subpage of 64KB page
b0011 = 4KB page
b0001 = 1KB page or 1KB subpage of 4KB page.
b1011 = 1MB section
b0111 = 64KB page
b0101 = 16KB subpage of 64KB page
b0011 = 4KB page
b0001 = 1KB page or 1KB subpage of 4KB page.