Epson Stylus Photo 750, Service Manual

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EPSON Stylus Photo 750 Revision A
Product Description Parallel Interface 17
NOTE: Following lists “Notes” when using the parallel interface.
1. “Return GND pin” in the table means twist pair return and is
connected to the signal GND level.
Also, these cables are shielded wires and it is effective means to
connect to each chassis GND in the PC and printer for electrostatic
noise.
2.Conditions for interface are based on TTL level. Rise and fall time
should be within 0.2
µ
s.
3.Refer to figure1-9 for transmission of timing of each signals.
4.Do not perform data transmission ignoring -ACK or BUSY signals.
(Perform the data transmission after confirming that -ACK and BUSY
signals are Low)
5.It is possible to perform the printing test including interface circuit
without using equipment from outside when 8-bit data signal(20-27 pin)
is set to appropriate word code and connect then forcefully to -ACK and
-STRB. However, to perform this, it is necessary to set “Parallel I/F
mode” of EEPROM as normal. Also, set the IEEE-1284.4 packet mode
Off.
The figure below shows the timing chart of the parallel interface.
Figure 1-9. Timing Chart
Typical time of tack is shown below.
Table 1-10. Typical Time of Tack
Parallel I/F Mode Typical time of tack
High speed 0.5
µ
S
Normal speed 2
µ
S
D A T A
/ S T R B
B U S Y
/ A C K
d a t a b y t e n d a t a b y t e n + 1
t
h o l d
t
s e t u p
t
s t b
t
n e x t
t
r e a d y
t
b u s y
t
r e p l y
t
a c k
t
n b u s y
t t - o u t M a x . 1 2 0 n s : R i s e a n d f a l l t i m e o f e v e r y o u t p u t s i g n a l s
t t - i n M a x . 2 0 0 n s : R i s e a n d f a l l t i m e o f e v e r u i n p u t s i g n a l s