HT46R62 Holtek Semiconductor Inc., HT46R62 Datasheet - Page 23

• Manufacturer Part Number: HT46R62
• Description: Ht46r62/ht46c62 -- A/d With Lcd Type 8-bit Mcu
• Manufacturer: Holtek Semiconductor Inc.

LCD Display Memory
The device provides an area of embedded data memory
for LCD display. This area is located from 40H to 53H 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~53H will effect the LCD display. When
the BP is cleared to 0 , any data written into 40H~53H
means to access the general purpose data memory.
The LCD display memory can be read and written to
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.
Rev. 1.70
mov
mov
jmp
a,ADRL
adrl_buffer,a
:
:
start_conversion
Display Memory
; read conversion result low byte value from the ADRL register
; save result to user defined memory
; start next A/D conversion
A/D Conversion Timing
23
LCD Driver Output
The output number of the device LCD driver can be 20 2
or 20 3 or 19 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.
Note:
1/3 Bias
1/2 Bias
Condition
The 52-pin QFP package does not support the
charge pump (C type bias) of the LCD. The LCD
bias type must select the R type by option.
(V
(V
Low Bias Current
LCD
LCD
²R² Type Bias Current
/4.5) 15 A
/3) 15 A
(Typ.)
HT46R62/HT46C62
Option
(V
(V
High Bias Current
LCD
LCD
February 14, 2006
/4.5) 45 A
/3) 45 A
(Typ.)