Registers: 0x54 (0xD4)

SCSI Output Data Latch (SODL)

Read/Write

15

0

SODL

x x

x x

x

x

x

x

x

x

x

x

 

 

 

 

x

x

x

x

SODL SCSI Output Data Latch[15:0]

This register is used primarily for diagnostic testing or programmed I/O operation. Data written to this register is asserted onto 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 any mode. It is also used to write to the synchronous data FIFO when testing the chip. The power-up value of this register is indeterminate.

Registers: 0x58 (0xD8)

SCSI Bus Data Lines (SBDL)

Read Only

15

0

SBDL

x x

x

x

x

x

x

x

x

x

x

x

 

 

 

 

x

x

x

x

SBDL SCSI Bus Data Lines[15:0]

This register contains the SCSI data bus status. Even though the SCSI data bus is active low, these bits are active high. The signal status is not latched and is a true representation of exactly what is on the data bus at the time the register is read. This register is used when receiving data using programmed I/O. This register can also be used for diagnostic testing or in low level mode. The power-up value of this register is indeterminate.

5-66

Operating Registers

Page 140
Image 140
LSI 53C810A technical manual Registers 0x54 0xD4, Registers 0x58 0xD8