Avago Technologies LSI53C876E - Manual (Page 134)

4-40 Registers
Register: 0x0A
SCSI Selector ID (SSID)
Read Only
VAL SCSI Valid 7
If VAL is asserted, then the two SCSI IDs are detected
on the bus during a bus-initiated selection or reselection,
and the encoded destination SCSI ID bits below are valid.
If VAL is deasserted, only one ID is present and the
contents of the encoded destination ID are meaningless.
R Reserved [6:4]
ENID Encoded Destination SCSI ID [3:0]
Reading the SSID register immediately after the
LSI53C876 SCSI function is selected or reselected
returns the binary-encoded SCSI ID of the device that
performed the operation. These bits are invalid for targets
that are selected under the single initiator option of the
SCSI-1 specification. This condition is detected by
examining the VAL bit above.
7 6 4 3 0
VAL R ENID[3:0]
0 x x x 0 0 0 0