IBM PowerPC 604 User Manual page 162

Table 3-6. C&che Actions (Continued)
Cache MESI
Action
Bus Bus
TT0-4 RsV'n
Snoop
Action
WIM State Operation WIM Response
s
Snoop- xx1 01010
(wa)
~
NCH>p
read
E Snoop- xx1 01010 (wa)
~
Mark cache bbck S.
read
M Snoop- X01 01010 (wa)
AJ!tTRV&~
Attempt to write cache block
read back to main memory;
if successful, mark cache block S
M Snoop- x11 01010
(wa)
AJ!tTRV&~
Attempt to write cache block
read back to main memory;
n
successful, mark cache block S
I Snoop- XX1 11010 None (None) NCH>p
read
atomic
I Snoop-
xx1 11010 Yes
~
NCH>p
read
atomic
s
Snoop- xx1 11010 (wa)
~
NCH>p
read
atomic
E Snoop- xx1 11010
(wa)
~
Mark cache bbck S
read
atomic
M Snoop- xx1 11010
(wa)
AJ!tTRV&~
Attempt to write cache block
read
back to main memory; if
atomic
successful, mark cache block S.
I Snoop- xx1 01110
None (None)
NCH>p
RWITM
I
Snoop- xx1 01110
Yes
(None) Release reservation.
RWITM
(and
reset)
ES Snoop- xx1 01110 None (None) Mark cache block I.
RWITM
ES
Snoop-
xx1 01110
Yes
(None) Mark cache bbck I.
RWITM
(and
Release reservation.
reset)
M
Snoop- xx1 01110 None
AJ!tTRV&~
Attempt to write cache block
RWITM
back to main memory;
if successful, mark cache bbck I.
M
Snoop- xx1 01110 Yes
AJ!tTRV&~
Attempt to write cache block
RWITM
(and back to main memory;
reset) if successful, mark cache block I,
release reservation
Chapter 3. cache and Bue Interface Unit Operation 3-39