
Chapter 6 Target Mode
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| 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:
BITS
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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0 | 0 | 0 | 0 | 0 | 0 | 0 | SAV |
Table 48:
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.
21020285 D | User’s Guide |