HT1609L
Functional Description
Y79 (refer to Note 2).
The HT1609L is an LCD driver LSI with 2×40
segment output channel. It operates with a con-
troller, such as HT163A, or another segment
driver LSI HT1608, HT1608L and HT1609L.
Data input/output
The DL1, DR1, DL2, DR2 are data input or
output option function. When SHF1 (SHF2) is
connected to VDD, the 40th bit data of the 1st
(2nd) 40-bit shift register outputs from DL1
(DL2) ; when SHF1 (SHF2) is connected to VSS
or open , the 1~40 (41~80) bits data from LCD
controller enter into the 1st (2nd) 40-bit shift
through DL1 (DL2).
Clock
The CLK1 is the clock to latch data on the
falling edge. It latches the data input from the
bidirectional shift register at the falling edge of
CLK1 and transfers its outputs to the LCD
driver circuit. The CLK2 is the clock to shift
data on the falling edge. It shifts the serial data
at the falling of CLK2 and transfers the output
of each bit of the register to the latch circuit
(refer to Note 1).
When SHF1 (SHF2) is connected to VDD, the
1~40 (41~80) bit data from the LCD controller
enter into the 1st (2nd)40-bit shift register
through DR1 (DR2); when SHF1 (SHF2) is con-
nected to VSS or open , the 40th bit shift regis-
ter outputs from DR1 (DR2) (refer to Note 2).
Bidirectional shift register
The HT1609L supplies two sets of 40-bit shift
register, which controls the shift direction by
SHF1 & SHF2. The SHF1 controls the 1st 40-
bit shift register, and SHF2 controls the 2nd
40-bit shift register. When SHF1 is connected to
VDD, the 1st shift direction is from Y39 to Y0;
when SHF1 is connected to VSS, the shift direc-
tion changes from Y0 to Y39. When SHF2 is
connected to VDD, the 2nd shift direction is
from Y79 to Y40; when SHF2 is connected to
VSS, the shift direction changes from Y40 to
LCD driver circuit
Select one of the four levels of voltage V1, V2,
V3,and V4 for driving an LCD and transfer it to
the output terminals according to the combina-
tion of alternate signal (ALT) and the data in
the latch circuit (refer to Note 1).
8
25th Aug ’98
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
