LSI LSI53C1000, Technical Manual

Page: 198 / 384

4-88 Registers
R Reserved [5:0]
Register: 0x53
Current Inbound SCSI Offset (CSO)
Read Only
R Reserved [7:6]
CSO[5:0] Current SCSI Offset [5:0]
These bits indicate the SCSI offset for synchronous
inbound transfers. This also represents the number of
data bytes in the SCSI FIFO in narrow transfer modes
and half the number of bytes in wide transfer mode. This
does not include any CRC or PAD bytes that may be in
the FIFO.
Registers: 0x54–0x55
SCSI Output Data Latch (SODL)
Read/Write
SODL SCSI Output Data Latch [15:0]
This register is used primarily for diagnostic testing and
programmed I/O operations. Data written to this register
is asserted on the SCSI data bus by setting the Assert
Data Bus bit in the
SCSI Control One (SCNTL1) register.
This register is used to send data using programmed I/O.
Data flows through this register when sending data in
SMODE [1:0] Operating Mode
00 Reserved
01 High Impedance State
10 SE
11 LVD SCSI
7 6 5 4 3 2 1 0
R CSO5 CSO4 CSO3 CSO2 CSO1 CSO0
0 0 0 0 0 0 0 0
15 0
SODL
x x x x x x x x x x x x x x x x