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 |
+===============================================================+