HT46RU66 Holtek Semiconductor Inc., HT46RU66 Datasheet - Page 31

• Manufacturer Part Number: HT46RU66
• Description: Ht46ru66/ht46cu66 -- A/d Type 8-bit Mcu With Lcd
• Manufacturer: Holtek Semiconductor Inc.

LCD Memory
The device provides an area of embedded data memory
for LCD display. This area is located from 40H to 6EH of
the RAM at Bank 1. Bank pointer (BP; located at 04H of
the RAM) is the switch between the RAM and the LCD
display memory. When the BP is set as 1 , any data
written into 40H~6EH will affect the LCD display. When
the BP is cleared to 0 , 2 or 3 , any data written into
40H~6EH is map into the general purpose data mem-
ory. The LCD display memory can be read and written to
LCD Segments as Logical Output
The SEG0~SEG23 also can be optioned as logical output, once an LCD segment is optioned as a logical output, the
contents of bit0 of the related segment address in the LCD RAM will appear on the segment.
SEG0~SEG7 are all byte optioned as logical outputs, SEG8~SEG15 are also byte optioned as logical outputs,
SEG16~SEG23 are individually bit optioned as logical outputs.
Rev. 1.20
V
MAX
LCD Bias Type
LCD Type
Display Memory
If V
else V
1/2 bias
DD
>V
MAX
LCD
R Type
connect to V
, then V
1/3 bias
MAX
LCD
connect to V
31
1/2 bias
DD,
only by indirect addressing mode using MP1. When
data is written into the display data area, it is automati-
cally read by the LCD driver which then generates the
corresponding LCD driving signals. To turn the display
on or off, a 1 or a 0 is written to the corresponding bit
of the display memory, respectively. The figure illus-
trates the mapping between the display memory and
LCD pattern for the device.
LCD Driver Output
The output number of the device LCD driver can be 47 2
or 47 3 or 46 4 by option (i.e., 1/2 duty, 1/3 duty or 1/4
duty). The bias type LCD driver can be R type or C
type. If the R bias type is selected, no external capaci-
tor is required. If the C bias type is selected, a capaci-
tor mounted between C1 and C2 pins is needed. The
LCD driver bias voltage can be 1/2 bias or 1/3 bias by
option. If 1/2 bias is selected, a capacitor mounted be-
tween V2 pin and ground is required. If 1/3 bias is se-
lected, two capacitors are needed for V1 and V2 pins.
Refer to application diagram.
If V
else V
DD
>
MAX
3
2
V
connect to V1
LCD
C Type
HT46RU66/HT46CU66
, then V
1/3 bias
MAX
connect to V
October 2, 2007
DD
,