AMD AMD5K86 - Snooping

AMD~
AMD5/J6 Processor Technical Reference Manual
18524BjO-Mar1996
TABLE 2-3. Cache States for Snoops, Invalidation, and Replacements
Type of
Tags
l
Cache State Memory
Cache State After Operation
Operation Before
Access
3
Operation
3
MESI StateS
Writeback·
Writethrough
State
shared or
INV=O
shared write through
-
exclusive
Inquire
INV=l
invalid invalid
Cycle
Physical
INV=O
shared writethrough
modified
burst write
(writeback)
INV=l
invalid invalid
shared or
-
exclusive
Internal
Physical
invalid invalid
Snoop
modified
burst write
(write back)
shared or
-
exclusive
FLUSH
Physical
invalid invalid
Signal
modified
burst write
(writeback)
shared or
-
exclusive
WBINVD
Physical
invalid invalid
Instruction
burst write
modified
(writeback)
INVD
invalid invalid
Instruction
-
- -
shared or
exclusive
-
Depends on
Cache-Line
Replacement
Physical
burst write
replacement-line
modified
characteristics
(writeback)
Notes:
1. Linear tags are masked by i'12i5M, physical tags are not.
2. Writeback = 32 bytes.
3.
MESI state is stored in the physical tags. Instruction-cache state consists only of valid (shared) or invalid, and there are no write-
related states.
- Not applicable or none.
2-20
Internal Architedure