HT68F14 HOLTEK [Holtek Semiconductor Inc], HT68F14 Datasheet - Page 34

• Manufacturer Part Number: HT68F14
• Description: Enhanced I/O Flash Type MCU
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

Operating Mode Switching
Rev. 1.10
The device can switch between operating modes dynamically allowing the user to select the best
performance/power ratio for the present task in hand. In this way microcontroller operations that do
not require high performance can be executed using slower clocks thus requiring less operating current
and prolonging battery life in portable applications.
In simple terms, Mode Switching between the NORMAL Mode and SLOW Mode is executed using
the HLCLK bit and CKS2~CKS0 bits in the SMOD register while Mode Switching from the
NORMAL/SLOW Modes to the SLEEP/IDLE Modes is executed via the HALT instruction. When a
HALT instruction is executed, whether the device enters the IDLE Mode or the SLEEP Mode is
determined by the condition of the IDLEN bit in the SMOD register and FSYSON in the WDTC
register.
When the HLCLK bit switches to a low level, which implies that clock source is switched from the
high speed clock source, f
speed clock source will stop running to conserve power. When this happens it must be noted that the
f
internal functions such as the TMs. The accompanying flowchart shows what happens when the
device moves between the various operating modes.
H
/16 and f
H
/64 internal clock sources will also stop running, which may affect the operation of other
H
, to the clock source, f
34
Enhanced I/O Flash Type MCU
HT68F13/HT68F14/HT68F15
H
/2~f
H
/64 or f
L
. If the clock is from the f
February 9, 2011
L
, the high