Response id zero (respid0), Response id one, Respid1) – LSI 53C875A User Manual
Page 178: Response id one (respid1), Register: 0x4a, Register: 0x4b
4-86
Registers
Register: 0x4A
Response ID Zero (RESPID0)
Read/Write
RESPIO0
Response ID Zero
[7:0]
RESPID0 and
contain the
selection or reselection IDs. In other words, these two
8-bit registers contain the ID that the chip responds to on
the SCSI bus. Each bit represents one possible ID with
the most significant bit of RESPID1 representing ID 15
and the least significant bit of RESPID0 representing
ID 0. The
register still contains the
chip ID used during arbitration. The chip can respond to
more than one ID because more than one bit can be set
in the RESPID1 and RESPID0 registers. However, the
chip can arbitrate with only one ID value in the SCID
register.
Register: 0x4B
Response ID One (RESPID1)
Read/Write
RESPID1
Response ID One
[7:0]
and RESPID1 contain the
selection or reselection IDs. In other words, these two
8-bit registers contain the ID that the chip responds to on
the SCSI bus. Each bit represents one possible ID with
the most significant bit of RESPID1 representing ID 15
and the least significant bit of RESPID0 representing
ID 0. The
register still contains the
chip ID used during arbitration. The chip can respond to
more than one ID because more than one bit can be set
in the RESPID1 and RESPID0 registers. However, the
7
0
RESPID0
x
x
x
x
x
x
x
x
7
0
RESPID1
x
x
x
x
x
x
x
x