
Functional Description
2-8
Copyright © 2007, 2008 ARM Limited. All rights reserved.
ARM DDI 0402B
tag RAM present is tested along with the rest of the tag and is mapped to
MBISTDIN[22]
. Lockdown by line is tested with the rest of the tag and is mapped to
MBISTDIN[21]
.
For all cases:
•
lockdown by line
TAGLWD=MBISTDIN[21]
•
parity
TAGPWD=MBISTDIN[22]
.
Table 2-6 shows the address range of the
MBISTADDR
bus used to test the tag RAM,
based on the L2 cache size and configured to be 16-way.
Table 2-5 MBISTADDR and MBISTDIN mapping for tag RAM, 8-way
L2
cache
size
Way
size
Number of
tag RAM
indexes
MBISTADDR to tag RAM mapping
MBISTDIN to tag RAM mapping
128KB
16KB
512
TAGADDR[8:0]
=
MBISTADDR[10:2]
TAGWD[20:0]
=
MBISTDIN[20:0]
256KB
32KB
1,024
TAGADDR[9:0]
=
MBISTADDR[11:2]
TAGWD[20:1]
=
MBISTDIN[20:1]
512KB
64KB
2,048
TAGADDR[10:0]
=
MBISTADDR[12:2]
TAGWD[20:2]
=
MBISTDIN[20:2]
1MB
128KB
4,096
TAGADDR[11:0]
=
MBISTADDR[13:2]
TAGWD[20:3]
=
MBISTDIN[20:3]
2MB
256KB
8,192
TAGADDR[12:0]
=
MBISTADDR[14:2]
TAGWD[20:4]
=
MBISTDIN[20:4]
4MB
512KB
16,384
TAGADDR[13:0]
=
MBISTADDR[15:2]
TAGWD[20:5]
=
MBISTDIN[20:5]
Table 2-6 MBISTADDR and MBISTDIN mapping for tag RAM, 16-way
L2
cache
size
Way
size
Number of
tag RAM
indexes
MBISTADDR to tag RAM mapping
MBISTDIN to tag RAM mapping
256KB
16KB
512
TAGADDR[8:0]
=
MBISTADDR[10:2]
TAGWD[20:0]
=
MBISTDIN[20:0]
512KB
32KB
1,024
TAGADDR[9:0]
=
MBISTADDR[11:2]
TAGWD[20:1]
=
MBISTDIN[20:1]
1MB
64KB
2,048
TAGADDR[10:0]
=
MBISTADDR[12:2]
TAGWD[20:2]
=
MBISTDIN[20:2]
2MB
128KB
4,096
TAGADDR[11:0]
=
MBISTADDR[13:2]
TAGWD[20:3]
=
MBISTDIN[20:3]
4MB
256KB
8,192
TAGADDR[12:0]
=
MBISTADDR[14:2]
TAGWD[20:4]
=
MBISTDIN[20:4]
8MB
512KB
16,384
TAGADDR[13:0]
=
MBISTADDR[15:2]
TAGWD[20:5]
=
MBISTDIN[20:5]