Register: 0x0D

SCSI Status Zero (SSTAT0)

Read Only

7

6

5

 

4

3

2

1

 

0

ILF

ORF

OLF

 

AIP

LOA

WOA

RST

 

SDP0

 

 

 

 

 

 

 

 

 

 

0

0

0

 

0

0

0

0

 

0

 

 

 

 

 

 

 

 

 

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.

4-42Registers

Page 134
Image 134
LSI 53C875A technical manual Ilf, Orf, Olf