Scsi Drive Pin Assignments And Signals - IBM F10 Service Manual

Table 39. Host SCSI Signal Descriptions (continued)
Signal Name
MSG
REQ
ACK
ATN
RST
DIFFSENS DIFFERENTIAL SENSE A signal indicating if the bus is LVD, SE, or differential.
DB(0-15,P,P1)

SCSI Drive Pin Assignments and Signals

Table 40 lists the SCA-2 interface pin assignments for the SCSI disk drives.
Table 41 describes each SCSI signal.
Table 40. SCA-2 Interface Pin Assignments
Pin Signal
1 +12 V charge
2 +12 V
3 +12 V
4 +12 V
5 NC (Opt. 3.3 V)
6 NC (Opt. 3.3 V)
7 -DB(11)
8 -DB(10)
9 -DB(9)
10 -DB(8)
11 -I/O
12 -REQ
13 -C/D
14 -SEL
15 -MSG
16 -RST
17 -ACK
18 -BSY
19 -ATN
20 -DB(P)
Table 41. Drive SCSI Signal Descriptions
Signal Name
+12 V +12 V power
Description
MESSAGE A signal driven by the Target during a MESSAGE phase.
REQUEST A signal driven by the Target to indicate a request for an REQ/ACK
data transfer handshake.
ACKNOWLEDGE A signal driven by the Initiator to indicate acknowledgment for an
REQ/ACK data transfer handshake.
ATTENTION A signal driven by the Initiator indicating an ATTENTION condition.
RESET An "or-tied" signal indicating the RESET condition.
DATA BUS, PARITY Sixteen-bit data bus with odd parity used for data transfer and
BUS DEVICE ID during ARBITRATION
Pin Signal
21 -DB(7)
22 -DB(6)
23 -DB(5)
24 -DB(4)
25 -DB(3)
26 -DB(2)
27 -DB(1)
28 -DB(0)
29 -DB(P1)
30 -DB(15)
31 -DB(14)
32 -DB(13)
33 -DB(12)
34 +5 V
35 +5 V
36 +5 V charge
37 SPINDL SYNC +
38 RMT_START
39 SCSI ID0 +
40 SCSI ID2 +
Description
Power supply voltage for the drives.
Pin Signal
41 GROUND
42 GROUND
43 GROUND
44 Mated 1
45 NC (Opt. 3.3 V
charge)
46 DIFFSENSE*
47 +DB(11)*
48 +DB(10)*
49 +DB(9)*
50 +DB(8)*
51 +I/O*
52 +REQ*
53 +C/D*
54 +SEL*
55 +MSG*
56 +RST*
57 +ACK*
58 +BSY*
59 +ATN*
60 +DPP*
Chapter 14. Technical Reference
Pin Signal
61 +DB(7)*
62 +DB(6)*
63 +DB(5)*
64 +DB(4)*
65 +DB(3)*
66 +DB(2)*
67 +DB(1)*
68 +DB(0)*
69 +DB(P1)*
70 +DB(15)*
71 +DB(14)*
72 +DB(13)*
73 +DB(12)*
74 Mated 2
75 GROUND
76 GROUND
77 ACTIVE_LED
78 DLYD_START
79 SCSI ID1 +
80 SCSI ID3 +
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