Interface; Parallel Interface (Forward Channel) - Epson 680Pro - LQ B/W Dot-matrix Printer Service Manual

EPSON Stylus COLOR 680/777/777i

1.3 INTERFACE

The EPSON Stylus COLOR 680/777/777i provide USB and parallel interface as
standard.

1.3.1 Parallel Interface (Forward Channel)

Transmission Mode: 8 bit parallel, IEEE-1284 compatibility mode
Synchronization: By STROBE pulse
Handshaking: BY BUSY and ACKNLG signal
Signal Level: TTL compatible level
Adaptable Connector: 57-30360 (amphenol) or equivalent
BUSY signal is set high before setting either -ERROR low or PE high, and held high
until all these signals return to their inactive state.
BUSY signal is at high level in the following cases:
n During data entry (see data transmission timing).
n When input data buffer is full.
n During -INIT signal is at low level or during hardware initialization.
n During printer error (see -ERROR signal).
n When the parallel interface is not selected.
ERROR signal is at low level when the printer is in one of the following states:
n Printer hardware error (fatal error)
n Paper-out error
n Paper-jam error
n Ink-out error
PE signal is at high level during paper-out error.
PRODUCT DESCRIPTION
DATA
-STROBE
t
setup
BUSY
t
ready
-ACKNLG
Figure 1-3. Data Transmission Timing
Parameter
tsetup
thold
tstb
tready
tbusy
tt-out*
tt-in**
treply
tack
tnbusy
tnext
* Rise and fall time of every output signal.
** Rise and fall time of every input signal.
*** Typical timing for tack is shown on the following page.
INTERFACE
data byte n
data byte n+1
t
hold
t
next
t
stb
t
busy
t
t t
reply ack nbusy
Table 1-3.
Minimum Maximum
500ns
500ns
500ns
0
- 500ns
- 120ns
- 200ns
0
500ns 10us
0
0
Revision B
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