- 
NULL -> SS - NULL mode to subshared mode
 
- 
NULL -> SX - NULL mode to shared exclusive mode
 
- 
NULL -> S - NULL mode to shared mode
 
- 
NULL -> SSX - NULL mode to subshared exclusive mode
 
- 
NULL -> X - NULL mode to exclusive mode
 
- 
SS -> SX - Subshared mode to shared exclusive mode
 
- 
SS -> S - Subshared mode to shared mode
 
- 
SS -> SSX - Subshared mode to subshared exclusive mode
 
- 
SS -> X - Subshared mode to exclusive mode
 
- 
SX -> S - Shared exclusive mode to shared mode
 
- 
SX -> SSX - Shared exclusive mode to subshared exclusive mode
 
- 
SX -> X - Shared exclusive mode to exclusive mode
 
- 
S -> SX - Shared mode to shared exclusive mode
 
- 
S -> SSX - Shared mode to subshared exclusive mode
 
- 
S -> X - Shared mode to exclusive mode
 
- 
SSX -> X - Sub-shared exclusive mode to exclusive mode