Epson Stylus Color C70, Service Manual

Page: 17 / 216

EPSON Stylus COLOR C70/C80 Revision A
PRODUCT DESCRIPTION INTERFACE 17
1.3.2 Parallel Interface (Reserve Channel)
Transmission Mode: IEEE-1284 nibble mode
Adaptable Connector: See forward channel
Synchronization: Refer to the IEEE-1284 specification
Handshaking: Refer to the IEEE-1284 specification
Data Trans. Timing: Refer to the IEEE-1284 specification
Signal Level: IEEE-1284 level 1 device
See forward channel
NOTE: In/Out refers to the direction of signal flow from the printer’s point of
view.
Table 1-9. Connector Pin Assignment and Signals
Pin No. Signal Name
Return
GND Pin
In/Out Functional Description
1 Host Clk 19 In Host clock signal.
2 DATA 0 20 In
The DATA 0 through DATA 7 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.
3 DATA 1 21 In
4 DATA 2 22 In
5 DATA 3 23 In
6 DATA 4 24 In
7 DATA 5 25 In
8 DATA 6 26 In
9 DATA 7 27 In
10 PtrClk 28 Out Printer clock signal.
11
PtrBusy /
DataBit-3,7
29 Out
Printer busy signal and reverse channel
transfer data bit 3 or 7.
12
AckDataReq
/ DataBit-2,6
28 Out
Acknowledge data request signal and
reverse channel transfer data bit 2 or 6.
13
Xflag /
DataBit-1,5
28 Out
X-flag signal and reverse channel
transfer data bit 1 or 5.
14 Host Busy 30 In Host busy signal.
31 -INIT 30 In Not used.
32
-DataAvail /
DataBit-0,4
29 Out
Data available signal and reverse channel
transfer data bit 0 or 4.
36 1284-Active 30 In 1284 active signal.
18 Logic-H - Out Pulled up to +5V via 3.9K ohm resistor.
35 +5V - Out Pulled up to +5V via 3.3K ohm resistor.
17 Chassis GND - - Chassis GND
16,33,
19-30
GND - - Signal GND
15,34 NC - - Not connected
Table 1-9. Connector Pin Assignment and Signals (continued)
Pin No. Signal Name
Return
GND Pin
In/Out Functional Description