HT45R37V Holtek Semiconductor Inc., HT45R37V Datasheet - Page 68

• Manufacturer Part Number: HT45R37V
• Description: C/r-f Type 8-bit Otp Mcu
• Manufacturer: Holtek Semiconductor Inc.

gether with f
internal functions such as the Watchdog Timer, Buzzer,
RTC Interrupt and Time Base Interrupt. The internal
clock f
configuration option.
Operating Modes
After the correct clock source configuration selections
are made, overall operation of the chosen clock is
achieved using the CLKMOD register. A combination of
the HLCLK and IDLEN bits in the CLKMOD register and
use of the HALT instruction determine in which mode the
device will be run. The devices can operate in the follow-
ing Modes.
Rev. 1.00
Normal Mode
f
pending upon the WDT configuration option and WDT
control register.
Slow Mode0
f
lator, f
upon the WDT configuration option and WDT control
register.
M
M
on, f
off, f
S
, is simply a choice of either f
SYS
SLOW
SLOW
=f
SYS
SLOW
=32K_INT oscillator or the 32768Hz oscil-
on, f
/4, it is used as a clock source for certain
, CPU on, f
SYS
=f
M
, CPU on, f
S
on, f
WDT
SUB
S
on, f
on/off depending
or f
Clock Control Register - CLKMOD
WDT
SYS
/4, using a
on/off de-
68
Switching Between Modes
The device switches between the different operating
modes using a combination of the HALT instruction and
the IDLEN bit in the CLKMOD register. Switching to one
of the lower power modes enables the normal operating
current to be reduced to a lower operating level or to a
very low standby current level, a feature which is very
important in low power battery applications.
Slow Mode1
f
on/off depending upon the WDT configuration option
and WDT control register.
Idle Mode
f
f
configuration option and WDT control register.
Sleep Mode
f
upon the WDT configuration option and WDT control
register.
M
M
SUB
M
, f
, f
on, f
SLOW
SLOW
or f
SLOW
, f
, f
SYS
SYS
SYS
=f
/4, f
M
off, CPU off; f
, f
/2~f
S
WDT
, CPU off; f
M
/64, f
on/off depending upon the WDT
SYS
SUB
=f
SUB
SLOW
on, f
, f
WDT
, CPU on, f
S
on/off by selecting
October 20, 2009
on/off depending
HT45R37V
S
on, f
WDT