HD66108 Datasheet, PDF (46/60 Pages) Hitachi Semiconductor – (RAM-Provided 165-Channel LCD Driver for Liquid Crystal Dot Matrix Graphics)

HD66108
5. Control Register (FCR) (Accessed with RS = 1, Register Number = (B’011)
This register (Figure 31), containing eight bits, has a variety of functions such as specifying the method
for accessing RAM, determining RAM valid area, and selecting the function of the LCD driving signal
output pins. It must be initialized as soon as possible after power-on since it determines the overall
operation of the HD66108T. The PON bit may have to be reset afterwards. If the DUTY bits are rewritten
after initialization at power-on (if values other than the initial values are desired), the display memory
will not preserve data; the display memory must be set again after a time period of t_CL1 or longer. For
determining t_CL1, refer to equation 1 (Section 3.1).
D7 D6 D5 D4 D3 D2 D1 D0
INC WLS PON
ROS
DUTY
(1) INC (address increment direction select)
1: X address is incremented
0: Y address is incremented
(2) WLS (word length (of display data) select)
1: 6-bit word
0: 8-bit word
(3) PON (row data protect on)
1: Protect function on
0: Protect function off
(4) ROS (row output (function of LCD driving output pins) select)
Bit
No. 4 3 Contents
0 0 0 165 column outputs
1 0 1 65 row outputs from the right side
2 1 0 65 row outputs from the left and right sides
3 1 1 33 row outputs from the right side
(5) DUTY (multiplexing duty ratio)
Bit
No. 2 1 0
Multiplexing
Duty Ratio
0
000
1/32
1
001
1/34
2
010
1/36
3
011
1/48
4
100
1/50
5
101
1/64
6
110
1/66
7
111
Invalid (testing mode)
Figure 31 Control Register
999