Avago Technologies LSI53C876E - Manual (Page 135)

SCSI Registers 4-41
Register: 0x0B
SCSI Bus Control Lines (SBCL)
Read Only
REQ SREQ/ Status 7
ACK SACK/ Status 6
BSY SBSY/ Status 5
SEL SSEL/ Status 4
ATN SATN/ Status 3
MSG SMSG/ Status 2
C/D SC_D/ Status 1
I/O SI_O/ Status 0
This register returns the SCSI control line status. A bit is set when the
corresponding SCSI control line is asserted. These bits are not latched;
they are a true representation of what is on the SCSI bus at the time the
register is read. The resulting read data is synchronized before being
presented to the PCI bus to prevent parity errors from being passed to
the system. This register is used for diagnostics testing or operation in
low level mode.
7 6 5 4 3 2 1 0
REQ ACK BSY SEL ATN MSG C/D I/O
x x x x x x x x