AM53CF94 Advanced Micro Devices, AM53CF94 Datasheet - Page 24

• Manufacturer Part Number: AM53CF94
• Description: Enhanced SCSI-2 Controller (ESC)
• Manufacturer: Advanced Micro Devices

24
Initiator Select without ATN Steps
Initiator Select with ATN Steps
Initiator Select with ATN3 Steps
Initiator Select with ATN and Stop Steps
Register (06H)
Register (06H)
Register (06H)
Register (06H)
Internal State
Internal State
Internal State
Internal State
Bits 2:0 (Hex)
Bits 2:0 (Hex)
Bits 2:0 (Hex)
Bits 2:0 (Hex)
AMD
0
4
3
2
0
4
3
2
0
0
4
3
2
0
0
0
1
Interrupt Status
Interrupt Status
Interrupt Status
Interrupt Status
Register (05H)
Register (05H)
Register (05H)
Register (05H)
Bits 7:0 (Hex)
Bits 7:0 (Hex)
Bits 7:0 (Hex)
Bits 7:0 (Hex)
20
18
18
18
20
18
18
18
18
20
18
18
18
18
20
18
18
Explanation
Arbitration steps completed. Selection time-out occurred, then disconnected
Selection without ATN steps fully executed
Sequence halted during command transfer due to premature phase change
(Target)
Arbitration and selection completed; sequence halted because Target failed to
assert command phase
Explanation
Arbitration steps completed. Selection time-out occurred then disconnected
Selection with ATN steps fully executed
Sequence halted during command transfer due to premature phase change;
some CDB bytes may not have been sent; check FIFO flags
Message out completed; sent one message byte with ATN true, then released
ATN; sequence halted because Target failed to assert command phase after
message byte was sent
Arbitration and selection completed; sequence halted because Target did not
assert message out phase; ATN still driven by ESC
Explanation
Arbitration steps completed. Selection time-out occurred then disconnected
Selection with ATN3 steps fully executed
Sequence halted during command transfer due to premature phase change;
some CDB bytes may not have been sent; check FIFO flags
One, two, or three message bytes sent; sequence halted because Target failed
to assert command phase after third message byte, or prematurely released
message out phase; ATN released only if third message byte was sent
Arbitration and selection completed; sequence halted because Target failed to
assert message out phase; ATN still driven by ESC
Explanation
Arbitration steps completed. Selection time-out occurred then disconnected
Arbitration and selection completed; sequence halted because Target failed to
assert message out phase; ATN still asserted by ESC
Message out completed; one message byte sent; ATN on
Am53CF94/Am53CF96
P R E L I M I N A R Y