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3
Z5380 SCSI
Z
ILOG
PS97SCC0100
D0
/DB7
/DB6
/DB5
/BSY
/ACK
/ATN
/RST
I//O
C//D
/MSG
/REQ
D1
D2
D3
D4
D5
D6
D7
A2
A1
VDD
A0
/IOW
/RESET
/EOP
/DACK
READY
/IOR
IRQ
DRQ
/CS
/DB4
/DB3
/DB2
/DB1
/DB0
/DBP
GND
/SEL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
Z5380
PIN DESCRIPTION
Microprocessor Bus
Figure 3 shows the pins and their respective functions for
both the DIP and PLCC.
A2-A0
Address Lines(Input). Address lines are used with
/CS, /IOR, or /IOW to address all internal registers.
/CS
Chip Select (Input, Active Low). This signal, in con-
junction with /IOR or /IOW, enables the internal register
selected by A2-A0, to be read from or written to.
/DACK
DMA Acknowledge (Input, Active Low). /DACK
resets DRQ and selects the data register for input or output
data transfers. /DACK is used by DMA controller instead of
/CS.
DRQ
DMA Request(Output, Active High). DRQ indicates
that the data register is ready to be read or written. DRQ is
asserted only if DMA mode is set in the Command Regis-
ter. DRQ is cleared by /DACK.
/DB3
/DB2
/DB1
D6
D7
A2
7
8
9
39
38
37
6
5
4
3
2
1
44 43 42 41 40
/
/
/
/
D
N
D
D
D
D
D
/DB0
10
/DBP
11
GND
12
GND
13
/SEL
14
/BSY
15
/ACK
16
/ATN
17
A1
36
VDD
35
N/C
34
A0
33
/IOW
32
/RESET
31
/EOP
30
/DACK
29
/
I
C
/
/
N
/
D
I
/
R
18 19 20 21 22 23 24 25 26 27 28
Z5380
D7-D0
Data Lines(Bi-directional, three-state, Active High).
Bi-directional microprocessor data bus lines. D0 is the
Least Significant Bit of the bus. Data bus lines carry data
and commands to and from the SCSI.
/EOP
End of Process(Input, Active Low). /EOP is used to
terminate a DMA transfer. If asserted during a DMA cycle,
the current byte will be transferred, but no additional bytes
will be requested.
/IOR
I/O Read(Input, Active Low). /IOR is used in conjunc-
tion with /CS and A2-A0 to read an internal register. It also
selects the Input Data Register when used with /DACK.
/IOW
I/O Write(Input, Active Low). /IOW is used in conjunc-
tion with /CS and A2-A0 to write an internal register. It also
selects the Output Data Register when used with /DACK.
Figure 3a. 40-Pin DIP Pin Configuration
Figure 3b. 44-Pin PLCC Pin Configuration