Ciprico Rimfire 3880 - Manual (Page 116)

21020285 D User’s Guide
Chapter 6 Target Mode Pass-through Commands
Page 6 - 14 Target Selection Data Structure
SCSI CDB fields
These 12 bytes contain the SCSI 6, 10, or 12 byte command received from the
initiator that selected the RF3880. The number of bytes that are valid is
specified in the CDB Length field of the Target Selection Data Structure. If the
CMD bit is clear (in the SCSI Flags field), this field is invalid.
Semaphore Field
Both the Host driver and the adapter use this field to flag that an action has been
taken. The format is as follows:
SAV Selection Area Valid - After the adapter has been selected by an
initiator and has placed valid data in the Target Selection Data Structure, it sets
the SAV bit to inform the Host. This bit is set immediately before the adapter
issues a Selection Interrupt (if not prohibited by a zero Interrupt level in the
Target Mode Enable command).After the data structure is read, it is up to the
Host to zero the structure. The RF3880 will not write new data to this area until
it has received a Channel Attention write of 2.
0
⇒
The Target Selection Data Structure has been read by the Host and the
area is ready for use by the adapter again.
1
⇒
The RF3880 has placed valid data into the memory location to be read by
the Host.
BITS
7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 SAV
Table 48: