Transfer Control Instructions
5-29
valid when the LSI53C895A is operating in Initiator mode.
Clear these bits when the LSI53C895A is operating in
Target mode.
RA
Relative Addressing Mode
23
When this bit is set, the 24-bit signed value in the
register is used as a
relative offset from the current DMA SCRIPTS Pointer
(DSP) address (which is pointing to the next instruction,
not the one currently executing). The relative mode does
not apply to Return and Interrupt SCRIPTS.
Jump/Call an Absolute Address
Start execution at the new absolute address.
Jump/Call a Relative Address
Start execution at the current address plus (or minus) the
relative offset.
Table 5.5
SCSI Phase Comparisons
MSG
C/D
I/O
SCSI Phase
0
0
0
Data-Out
0
0
1
Data-In
0
1
0
Command
0
1
1
Status
1
0
0
Reserved
1
0
1
Reserved
1
1
0
Message-Out
1
1
1
Message-In
Command
Condition Codes
Absolute Alternate Address
Command
Condition Codes
Don’t Care
Alternate Jump Offset
Содержание LSI53C895A
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