Table 76

+========-==================================-===================+
|  Mode  |  Description                     |  Implementation   |
|        |                                  |  requirements     |
|--------+----------------------------------+-------------------|
|  000b  |  Write combined header and data  |  Optional         |
|  001b  |  Vendor-specific                 |  Vendor-specific  |
|  010b  |  Write data                      |  Optional         |
|  011b  |  Reserved                        |  Reserved         |
|  100b  |  Download microcode              |  Optional         |
|  101b  |  Download microcode and save     |  Optional         |
|  110b  |  Reserved                        |  Reserved         |
|  111b  |  Reserved                        |  Reserved         |
+===============================================================+