<s>
The	O
MERSI	B-General_Concept
protocol	I-General_Concept
is	O
a	O
cache	B-General_Concept
coherency	I-General_Concept
and	O
memory	B-Operating_System
coherence	I-Operating_System
protocol	I-Operating_System
used	O
by	O
the	O
PowerPC	B-General_Concept
G4	I-General_Concept
.	O
</s>
<s>
The	O
M	O
,	O
E	O
,	O
S	O
and	O
I	O
states	O
are	O
the	O
same	O
as	O
in	O
the	O
MESI	B-General_Concept
protocol	I-General_Concept
.	O
</s>
<s>
In	O
both	O
the	O
MESI	B-General_Concept
and	O
MERSI	B-General_Concept
protocols	I-General_Concept
,	O
the	O
transition	O
from	O
the	O
E	O
to	O
M	O
is	O
silent	O
.	O
</s>
