Parallel Interface (Reserve Channel) - Epson Stylus PHOTO 890 Service Manual

EPSON Stylus PHOTO 890/1280/1290

1.3.2 Parallel Interface (Reserve Channel)

o
Transmission Mode: IEEE-1284 nibble mode
o
Adaptable Connector See forward channel.
o
Synchronization: Refer to the IEEE-1284 specification
Pin No.
1
2-9
10
11 PtrBusy / DataBit-3,7
12 AckDataReq / DataBit-2,6
13 Xflag / DataBit-1,5
14
31
32 -DataAvail / DataBit-0,4
36
18
35
17
16,33, 19-30
15,34
NOTE: In/Out refers to the direction of signal flow from the printer's point of view.
o
Extensibility Request:
The printer responds affirmatively when the extensibility request values are 00H
or 04H, which means:
PRODUCT DESCRIPTIONS
Table 1-13. Connector Pin Assignment and Signals
Return
Signal Name In/Out
GND Pin
HostClk 19 In
DATA0-DATA7 20-27 In
PtrClk 28 Out
29 Out
28 Out
28 Out
HostBusy 30 In
-INIT 30 In
29 Out
1284-Active 30 In
Logic-H - Out
+5V - Out
Chassis GND -
GND -
NC -
o
Handshaking:
o
Data Trans. Timing:
o
Signal Level:
Host clock signal.
The DATA0 through DATA7 signals represent data bits 0 to 7, respectively. Each signal is
at high level when data is logical 1 and low level when data is logical 0. These signals are
used to transfer the 1284 extensibility request values to the printer.
Printer clock signal.
Printer busy signal and reverse channel transfer data bit 3 or 7.
Acknowledge data request signal and reverse channel transfer data bit 2 or 6.
X-flag signal and reverse channel transfer data bit 1 or 5.
Host busy signal.
Not used.
Data available signal and reverse channel transfer data bit 0 or 4.
1284 active signal.
Pulled up to +5V via 3.9K ohm resistor.
Pulled up to +5V via 3.3K ohm resistor.
- Chassis GND
- Signal GND
- Not connected
n
00H:
n
04H:
Interface
Refer to the IEEE-1284 specification
Refer to the IEEE-1284 specification
IEEE-1284 level 1 device (See forward channel.)
Functional Description
Request Nibble Mode Reverse Channel Transfer.
Request Device ID;
Return Data Using Nibble Mode Rev Channel Transfer.
Revision C
25