This field holds the byte address of the
executing command of the descriptor table. At the start of ADMA, the user must set
the start address of the descriptor table. The ADMA increments this register address,
which points to the next Descriptor line to be fetched.
When the ADMA Error (ADMA) status flag rises, this field holds a valid descriptor address depending on the ADMA Error State (ERRST). The user must program Descriptor Table on 32-bit boundary and set 32-bit boundary address to this register. ADMA2 ignores the lower 2 bits of this register and assumes it to be 0.