Level 2 Memory Interface
ARM DDI 0388I
Copyright © 2008-2012 ARM. All rights reserved.
8-4
ID073015
Non-Confidential
•
For the instruction side read bus,
ARIDM1
, is encoded as follows:
—
2'b00 for outstanding transactions
—
2'b01 for outstanding transactions
—
2'b10 for outstanding transactions
—
2'b11 for outstanding transactions.
•
For the data side write bus,
AWIDM0
, is encoded as follows:
—
2'b00 for noncacheable accesses
—
2'b01 is unused
—
2'b10 for linefill 0 evictions
—
2'b11 for linefill 1 evictions.
8.1.4
AXI USER bits
The AXI USER bits encodings are as follows:
Data side read bus,
ARUSERM0[6:0]
shows the bit encodings for
ARUSERM0[6:0]
Instruction side read bus,
ARUSERM1[6:0]
shows the bit encodings for
ARUSERM1[6:0]
.
Table 8-3
ARUSERM0[6:0]
encodings
Bits
Name
Description
[6]
Reserved
b0
[5]
L2 Prefetch hint
Indicates that the read access is a prefetch hint to the L2, and does not expect any data back
[4:1]
Inner attributes
b0000
Strongly Ordered
b0001
Device
b0011
Normal Memory Non-Cacheable
b0110
Write-Through
b0111
Write-Back no Write-Allocate
b1111
Write-Back Write-Allocate.
[0]
Shared bit
0
Nonshared
1
Shared.
Table 8-4
ARUSERM1[6:0]
encodings
Bits
Name
Description
[6]
Reserved
b0