![](http://datasheet.mmic.net.cn/390000/HT49C10_datasheet_16811623/HT49C10_23.png)
HT49C10
23
September 28, 1999
written into 40H~52H will affect the LCD dis-
play. When the BP is cleared 0 , any data writ-
ten into 40H~52H means to access the general
purpose data memory. The LCD display mem-
ory can be read and written to, only by indirect
addressing mode using MP1. When data is
writxten into the display data area it is auto-
matically read by the LCD driver which then
generates the corresponding LCD driving sig-
nals. 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 illustrates the
mapping between the display memory and LCD
pattern for the HT49C10.
LCD driver output
The output number of the HT49C10 LCD driver
can be 19 2 or 19 3 or 18 4 by mask option (i.e.,
1/2dutyor1/3dutyor1/4duty).Thebiastypeof
LCD driver can be R type or C type. If the
R bias type is selected, no external capacitor
is required. If the C bias type is selected, a ca-
pacitor mounted between C1 and C2 pins is
needed. The bias voltage of LCD driver can be
1/2 bias or 1/3 bias by mask option. If 1/2 bias is
selected, a capacitor mounted between V2 pin
and the ground is required. If 1/3 bias is se-
lected, two capacitors are needed for V1 and V2
pins. Please refer to the application diagram.
Buzzer
HT49C10providesapairofbuzzeroutputBZand
BZ, which share pins with PA0 and PA1 respec-
tively, as determined by mask option. Its output
frequency can be selected by mask option.
When the buzzer function is selected, setting
PA.0 and PA.1 0 simultaneously will enable
the buzzer output and setting PA.0 1 will dis-
able the buzzer output.
Register Bit No. Label
Read/Write
Reset
Function
RTCC
(09H)
0~2
RT0
RT1
RT2
R/W
0
8 to 1 multiplexer control inputs to select the
real time clock prescaler output
3
Unused bits, read as 0
4
QOSC
R/W
0
Control the RTC OSC to oscillate quickly.
0 enable
1 disable
5~7
Unused bits, read as 0
RTCC register