Avago Technologies LSI53C895A User Manual

Page 237

Advertising
background image

I/O Instruction

5-15

If reselected, the LSI53C895A fetches the next instruction
from the address pointed to by the 32-bit jump address
field stored in the

DMA Next Address (DNAD)

register.

Manually set the LSI53C895A to Initiator mode when it is
reselected.

If the CPU sets the SIGP bit in the

Interrupt Status Zero

(ISTAT0)

register, the LSI53C895A aborts the Wait Select

instruction and fetches the next instruction from the
address pointed to by the 32-bit jump address field stored
in the

DMA Next Address (DNAD)

register.

Set Instruction

When the SACK/ or SATN/ bits are set, the
corresponding bits in the

SCSI Output Control Latch

(SOCL)

register are set. Do not set SACK/ or SATN/

except for testing purposes. When the target bit is set,
the corresponding bit in the

SCSI Control Zero (SCNTL0)

register is also set. When the carry bit is set, the
corresponding bit in the Arithmetic Logic Unit (ALU) is
set.

Note:

None of the signals are set on the SCSI bus in Target
mode.

Clear Instruction

When the SACK/ or SATN/ bits are cleared, the
corresponding bits are cleared in the

SCSI Output Control Latch (SOCL)

register. Do not set

SACK/ or SATN/ except for testing purposes. When the
target bit is cleared, the corresponding bit in the

SCSI

Control Zero (SCNTL0)

register is cleared. When the

carry bit is cleared, the corresponding bit in the ALU is
cleared.

Note:

None of the signals are cleared on the SCSI bus in the
Target mode.

Advertising