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EPSON
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REVISION
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B
RP-U420 series
Specification
(STANDARD)
16
15
2.1.2.5 Interface Pin Assignments for Each Mode
Pin
Source
Compatibility Mode
Nibble Mode
Byte Mode
1
Host
nStrobe
HostClk
HostClk
2
Host/Ptr
Data0 (LSB)
Data0 (LSB)
Data0 (LSB)
3
Host/Ptr
Data1
Data1
Data1
4
Host/Ptr
Data2
Data2
Data2
5
Host/Ptr
Data3
Data3
Data3
6
Host/Ptr
Data4
Data4
Data4
7
Host/Ptr
Data5
Data5
Data5
8
Host/Ptr
Data6
Data6
Data6
9
Host/Ptr
Data7 (MSB)
Data7 (MSB)
Data7 (MSB)
10
Printer
nAck
PtrClk
PtrClk
11
Printer
Busy
PtrBusy/Data3, 7
PtrBusy
12
Printer
PError
AckDataReq/Data2, 6
AckDataReq
13
Printer
Select
Xflag/Data1, 5
Xflag
14
Hostr
nAutoFd
HostBusy
HostBusy
15
NC
ND
ND
16
GND
GND
GND
17
FG
FG
FG
18
Printer
Logic-H
Logic-H
Logic-H
19
GND
GND
GND
20
GND
GND
GND
21
GND
GND
GND
22
GND
GND
GND
23
GND
GND
GND
24
GND
GND
GND
25
GND
GND
GND
26
GND
GND
GND
27
GND
GND
GND
28
GND
GND
GND
29
GND
GND
GND
30
GND
GND
GND
31
Host
nInit
nInit
nInit
32
Printer
nFault
nDataAvail/Data0, 4
nDataAvail
33
GND
ND
ND
34
Printer
DK_STATUS
ND
ND
35
Printer
+5V
ND
ND
36
Host
nSelectIn
1284-Active
1284-Active
NOTES:
1. A prefix "n" to signal names refers to "L" active signals. To the host not provided with all
the signal lines listed above, both-way communication fails.
2. For interfacing, signal lines shall use twisted pair cables with the return sides connected
to signal ground level.
3. Interfacing conditions shall be all based on the TTL level to meet the characteristics
described below. In addition, both rise time and fall time of each signal shall be 0.5
µ
s or
less.