AMD AMD-K6-2/450 Design Guide - Page 60

Level-2 Cache Array Access Register (L2AAR), Each sector contains two 32-byte cache lines

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Preliminary Information Embedded AMD-K6™ Processors BIOS Design Guide 23913A/0-November 2000 Level-2 Cache Array Access Register (L2AAR) Model D also provides the L2AAR register that allows for direct access to the L2 cache and L2 tag arrays. Note: The L2AAR register is identical to the Model 9 implementation. Some information in this section is duplicated to account for the different L2 cache sizes in the AMD-K6-2E+ and AMD-K6-IIIE+ processors. The L2 cache in the AMD-K6-2E+ and AMD-K6-IIIE+ processors is organized as shown in Figure 18: s Four 32-Kbyte ways (AMD-K6-2E+ processor) or four 64Kbyte ways (AMD-K6-IIIE+ processor) s Each way contains 512 (AMD-K6-2E+ processor) or 1024 (AMD-K6-IIIE+ processor) sets s Each set contains four 64-byte sectors (one sector in each way) s Each sector contains two 32-byte cache lines s Each cache line contains four 8-byte octets s Each octet contains an upper and lower dword (4 bytes) Each line within a sector contains its own MESI state bits, and associated with each sector is a tag and LRU (Least Recently Used) information. Set 0 64 bytes Line1/MESI Line0/MESI Tag/LRU 64 bytes Line1/MESI Line0/MESI Tag/LRU 64 bytes Line1/MESI Line0/MESI Tag/LRU 64 bytes Line1/MESI Line0/MESI Tag/LRU Way 0 Way 1 Way 2 Way 3 512 or 1024 sets Set 1023 Figure 18. L2 Cache Organization 48 Model D Registers

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48
Model D Registers
Embedded AMD-K6™ Processors BIOS Design Guide
23913A/0—November 2000
Preliminary Information
Level-2 Cache Array Access Register (L2AAR)
Model D also provides the L2AAR register that allows for direct
access to the L2 cache and L2 tag arrays.
Note:
The
L2AAR
register
is
identical
to
the
Model
9
implementation. Some information in this section is
duplicated to account for the different L2 cache sizes in the
AMD-K6-2E+ and AMD-K6-IIIE+ processors.
The L2 cache in the AMD-K6-2E+ and AMD-K6-IIIE+ processors
is organized as shown in Figure 18:
Four 32-Kbyte ways (AMD-K6-2E+ processor) or four 64-
Kbyte ways (AMD-K6-IIIE+ processor)
Each way contains 512 (AMD-K6-2E+ processor) or 1024
(AMD-K6-IIIE+ processor) sets
Each set contains four 64-byte sectors (one sector in each
way)
Each sector contains two 32-byte cache lines
Each cache line contains four 8-byte octets
Each octet contains an upper and lower dword (4 bytes)
Each line within a sector contains its own MESI state bits, and
associated with each sector is a tag and LRU (Least Recently
Used) information.
Figure 18.
L2 Cache Organization
512 or 1024 sets
Set 0
64 bytes
Way 2
Line1/MESI
Line0/MESI
Tag/LRU
64 bytes
Way 1
Line1/MESI
Line0/MESI
Tag/LRU
64 bytes
Way 0
Line1/MESI
Line0/MESI
Tag/LRU
64 bytes
Way 3
Line1/MESI
Line0/MESI
Tag/LRU
Set 1023