HT66F016 View Datasheet(PDF) - Holtek Semiconductor
Part Name
Description
MFG CO.
'HT66F016' PDF : 116 Pages View PDF
HT66F016/HT66F017/HT68F016/HT68F017
HT66F016R/HT66F017R/HT68F016R/HT68F017R
Oscillator
Various oscillator options offer the user a wide range of
functions according to their various application require-
ments. The flexible features of the oscillator functions
ensure that the best optimisation can be achieved in
terms of speed and power saving. Oscillator selections
and operation are selected through a combination of
configuration options and registers.
Oscillator Overview
In addition to being the source of the main system clock
the oscillators also provide clock sources for the Watch-
dog Timer and Time Base Interrupts. External oscilla-
tors requiring some external components as well as fully
integrated internal oscillators, requiring no external
components, are provided to form a wide range of both
fast and slow system oscillators. All oscillator options
are selected through the configuration options. The
higher frequency oscillators provide higher performance
but carry with it the disadvantage of higher power re-
quirements, while the opposite is of course true for the
lower frequency oscillators. With the capability of dy-
namically switching between fast and slow system
clock, the device has the flexibility to optimize the perfor-
mance/power ratio, a feature especially important in
power sensitive portable applications.
Type
Name
Freq.
External Crystal HXT
400kHz~
20MHz
Internal High
Speed RC
HIRC
8MHz
Internal Low
Speed RC
LIRC
32kHz
Oscillator Types
Pins
OSC1/
OSC2
¾
¾
System Clock Configurations
There are methods of generating the system clock, two
high speed oscillators and one low speed oscillators.
The high speed oscillators are the external crystal/ce-
ramic oscillator - HXT and the internal 8MHz RC oscilla-
tor - HIRC. The low speed oscillator is the internal
32kHz oscillator - LIRC. Selecting whether the low or
high speed oscillator is used as the system oscillator is
implemented using the HLCLK bit and CKS2~CKS0 bits
in the SMOD register and as the system clock can be
dynamically selected.
H ig h S p e e d
O s c illa tio n
HXT
fH
6 - s ta g e P r e s c a le r
H IR C
fH /2
fH /4
fH /8
H ig h S p e e d O s c illa tio n
C o n fig u r a tio n O p tio n
fH /1 6
fH /3 2
fH /6 4
fL
fS Y S
L IR C
Low S peed
O s c illa tio n
H LC LK ,
C K S 2 ~ C K S 0 b its
fS U B
System Clock Configurations
F a s t W a k e -u p fro m S L E E P M o d e o r
ID L E M o d e C o n tr o l ( fo r H X T o n ly )
Rev. 1.40
30
November 22, 2016
Share Link: 
