Epson PX-8 Technical Manual page 104

(Top) XECL - measured at CN5, pin 8.
(Bottom) XSCL - measured at CN5, pin 3.
The XECL signal selects an X-drive IC
(SED1120) from X1 to X8 on the MAP-LD
board. 16 XSCL signal pulses correspond to
G
each on XECL pulse, and four display data bits
correspond to each on XSCL pulse. Thus, 64
data bits (display dots) are written to the select-
G
ed X-drive IC in succession. Fig. 2-81 shows
waveforms of the XECL and XSCL signals on
different time base. 15 XSCL pulses corre-
spond to the first XECL pulse and 16 XSCL
pulses correspond to each of the subsequent
XECL pulses.
G
G
G
G
2-80
REV.-A
2V 500mV 50).JS
11111111
11111111
111111111111 11111111111111
2V 500mV
5\.lS
]
~
1111111111111111111111111111111111111111I
2V
2V 500mV 500nS
UlJJ
2V
Fig.2-81 LCD X-LINE Display Control
Signal Waveforms