HT1622
Application Circuits
C
R
W
D
S
D
V
D
D
*
*
V
R
V
L
C
D
R
M
C
U
H
T
1
6
2
2
A
T
A
B
Z
P
i
e
z
o
*
R
B
Z
I
R
Q
C
O
M
0
~
C
O
M
7
S
E
G
0
~
S
E
G
3
1
1
/
4
B
i
a
s
,
1
/
8
D
u
t
y
L
C
D
P
a
n
e
l
Note: The connection of IRQ and RD pin can be selected depending on the requirement of the MCU.
The voltage applied to VLCD pin must be lower than VDD
.
Adjust VR to fit LCD display, at VDD=5V, VLCD=4V, VR=15kW±20%.
Adjust R (external pull-high resistance) to fit user¢s time base clock.
Command Summary
Name
ID
Command Code
D/C
D
Function
Read data from the RAM
Write data to the RAM
Def.
1 1 0
1 0 1
READ
A5A4A3A2A1A0D0D1D2D3
A5A4A3A2A1A0D0D1D2D3
WRITE
D
READ-MODIFY-
WRITE
1 0 1
1 0 0
A5A4A3A2A1A0D0D1D2D3
0000-0000-X
D
C
Read and Write data to the RAM
Turn off both system oscillator and LCD bias
generator
SYS DIS
Yes
Yes
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
SYS EN
0000-0001-X
0000-0010-X
0000-0011-X
0000-0100-X
0000-0101-X
0000-0110-X
0000-0111-X
0000-1000-X
0000-1101-X
0000-1111-X
0001-10XX-X
0001-11XX-X
010X-XXXX-X
0110-XXXX-X
100X-0XXX-X
100X-1XXX-X
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
Turn on system oscillator
LCD OFF
LCD ON
Turn off LCD display
Turn on LCD display
TIMER DIS
WDT DIS
TIMER EN
WDT EN
TONE OFF
CLR TIMER
CLR WDT
RC 32K
Disable time base output
Yes
Yes
Disable WDT time-out flag output
Enable time base output
Enable WDT time-out flag output
Turn off tone outputs
Yes
Clear the contents of the time base generator
Clear the contents of WDT stage
System clock source, on-chip RC oscillator Yes
System clock source, external clock source
Tone frequency output: 4kHz
EXT 32K
TONE 4K
TONE 2K
IRQ DIS
Tone frequency output: 2kHz
Disable IRQ output
Enable IRQ output
Yes
IRQ EN
Rev. 1.40
10
February 6, 2007
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
