LSI 53C875A - Manual (Page 134)

4-42 Registers
Register: 0x0D
SCSI Status Zero (SSTAT0)
Read Only
ILF SIDL Least Significant Byte Full 7
This bit is set when the least significant byte in the SCSI
Input Data Latch (SIDL) register contains data. Data is
transferred from the SCSI bus to the SCSI Input Data
Latch register before being sent to the DMA FIFO and
then to the host bus. The SIDL register contains SCSI
data received asynchronously. Synchronous data
received does not flow through this register.
ORF SODR Least Significant Byte Full 6
This bit is set when the least significant byte in the SCSI
Output Data Register (SODR, a hidden buffer register
which is not accessible) contains data. The SODR is
used by the SCSI logic as a second storage register
when sending data synchronously. It is not readable or
writable by the user. It is possible to use this bit to
determine how many bytes reside in the chip when an
error occurs.
OLF SODL Least Significant Byte Full 5
This bit is set when the least significant byte in the SCSI
Output Data Latch (SODL) contains data. The SODL
register is the interface between the DMA logic and the
SCSI bus. In synchronous mode, data is transferred from
the host bus to the SODL register, and then to the SCSI
Output Data Register (SODR, a hidden buffer register
which is not accessible) before being sent to the SCSI
bus. In asynchronous mode, data is transferred from the
host bus to the SODL register, and then to the SCSI bus.
The SODR buffer register is not used for asynchronous
transfers. It is possible to use this bit to determine how
many bytes reside in the chip when an error occurs.
7 6 5 4 3 2 1 0
ILF ORF OLF AIP LOA WOA RST SDP0
0 0 0 0 0 0 0 0