HT46R068B/HT46R069B
Enhanced A/D Type 8-bit OTP MCU
I
O
C
t
n
r
e
a
n
l
C
1
s
c
l
a
l
i
o
t
r
r
i
u
c
t
i
R
p
3
2
7
z
6
8
H
I
t
n
r
e
n
a
R
C
l
O
s
c
t
i
r
o
l
l
a
T
c
o
n
i
e
t
n
r
a
l
r
i
u
c
t
i
s
C
2
N
t
o
:
e
.
1
R
,
p
1
C
a
n
C
2
d
a
e
r
r
q
e
r
u
e
i
d
.
2
.
A
l
h
t
o
u
n
g
o
h
s
h
t
o
n
p
w
n
i
s
h
a
e
v
a
p
a
a
i
r
s
i
t
c
a
c
p
i
a
a
t
c
n
c
e
o
f
a
o
r
u
7
n
p
d
.
F
External LXT Oscillator - HXT
LXT Oscillator C1 and C2 Values
Crystal Frequency
C1
C2
3ꢃ7ꢄ8Hz
8pF
10pF
Note: 1. C1 and Cꢃ valꢀes aꢁe foꢁ gꢀidance onlꢂ.
ꢃ. RP=5M~10MΩ is ꢁecommended.
32768Hz Crystal Recommended Capacitor Values
LXT Oscillator Low Power Function
The LXT oscillator can function in one of two modes, the Quick Start Mode and the Low Power
Mode. The mode selection is executed using the LXTLP bit in the CTRL0 register.
LXTLP Bit
LXT Mode
Qꢀick Staꢁt
Low-poweꢁ
0
1
After power on the LXTLP bit will be automatically cleared to zero ensuring that the LXT
oscillator is in the Quick Start operating mode. In the Quick Start Mode the LXT oscillator will
power up and stabilise quickly. However, after the LXT oscillator has fully powered up it can be
placed into the Low-power mode by setting the LXTLP bit high. The oscillator will continue to run
but with reduced current consumption, as the higher current consumption is only required during
the LXT oscillator start-up. In power sensitive applications, such as battery applications, where
power consumption must be kept to a minimum, it is therefore recommended that the application
program sets the LXTLP bit high about 2 seconds after power-on.
It should be noted that, no matter what condition the LXTLP bit is set to, the LXT oscillator will
always function normally, the only difference is that it will take more time to start up if in the
Low-power mode.
Internal Low Speed Oscillator – LIRC
The LIRC is a fully self-contained free running on-chip RC oscillator with a typical frequency
of 13kHz at 5V requiring no external components. When the device enters the Idle/Sleep Mode,
the system clock will stop running but the WDT oscillator continues to free-run and to keep the
watchdog active. However, to preserve power in certain applications the LIRC can be disabled via
a configuration option.
Rev. 1.00
31
�anꢀaꢁꢂ ꢃꢄꢅ ꢃ011
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
