Table 157

+===========-=================================================================+ 
|   Value   |  Description                                                    | 
|-----------+-----------------------------------------------------------------| 
|     0h    |  Indicates the target should not distinguish between retaining  | 
|           |  the indicated data and data placed into the cache memory by    | 
|           |  other means (e.g. pre-fetch).                                  | 
|           |                                                                 | 
|     1h    |  Demand read retention priority:  Data put into the cache via a | 
|           |  READ command should be replaced sooner (has lower priority)    | 
|           |  than data placed into the cache by other means (e.g.           | 
|           |  pre-fetch).                                                    | 
|           |                                                                 | 
|           |  Write retention priority:  Data put into the cache during a    | 
|           |  WRITE or WRITE AND VERIFY command should be replaced sooner    | 
|           |  (has lower priority) than data placed into the cache by other  | 
|           |  means (e.g. pre-fetch).                                        | 
|           |                                                                 | 
|     Fh    |  Demand read retention priority:  Data put into the cache via a | 
|           |  READ command should not be replaced if there is other data in  | 
|           |  the cache that was placed into the cache by other means (e.g.  | 
|           |  pre-fetch) and it may be replaced (i.e. it is not locked).     | 
|           |                                                                 | 
|           |  Write retention priority:  Data put into the cache during a    | 
|           |  WRITE or WRITE AND VERIFY command should not be replaced if    | 
|           |  there is other data in the cache that was placed into the cache| 
|           |  by other means (e.g. pre-fetch) and it may be replaced (i.e.   | 
|           |  it is not locked).                                             | 
|           |                                                                 | 
|  2h - Eh  |  Reserved                                                       | 
+=============================================================================+