Interphase Tech CONDOR 4221 - Manual (Page 73)

Offboard Command Queue Entry
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DMA Transfer Control Word
This field specifies how the controller should DMA transfer the data from host memory. This field is fully defined in
the Common IOPB Structure definition, in the following section. Please refer there for full details.
Host Address
This field contains the physical address of the command, arranged in a big-endian order. The Host Address field points
to the beginning of an 12 byte CQE structure located immediately (or 12 bytes) before the beginning of the IOPB in
host system memory. After DMA transferring both the CQE and the IOPB from system memory, the controller will
associate this new CQE with the IOPB, which affects primarily the Command Tag field.
Offboard Transfer Length
If the host places zero in this field, the controller will use the default value of 12 bytes + 36 bytes for the combined
CQE/IOPB length. If in-line gathers are used which cause the size of the Transmit IOPB to exceed the default size of
36 bytes, the host needs to specify the total amount of data to transfer, in bytes, including both the CQE and the IOPB
located in system memory.
Work Queue Number
This value is not used, but is reported back when the command completes.