Casio IT-2000W Technical Reference Manual page 33

DOZE/RUN Transit Function
On this terminal the system will reduce the clock speed of the built-in CPU if no activity (access to
the touch panel, keys, COM1, or file) has occurred for a specified period of time (four seconds).
The state in which the CPU clock speed has been reduced is called the "DOZE state" and the state in
which the CPU is operating at full speed is called the "RUN state". If an activity occurs in the
DOZE state, the system returns to the RUN state. The DOZE/RUN transit function automatically
switches between the DOZE and RUN states.
RUN
Full speed
Usually, application programs do not have to anxious about the RUN/DOZE state.
The user may tolerate the operation speed since the system shifts to the RUN state whenever the user
attempts an action.
However, the clock speed is quickly reduced and CPU operation is slow if high-speed processing is
attempted intentionally or if system operation continues without user action (e.g. in a long
calculation). In order to avoid this, disable the power management function by means of the system
library (refer to Chapter 8.6.2 "System Library".).
Activity causing RUN/DOZE transition:


Touch panel input


Key input


Access to files


Access to COM1
Note:
If the power management function is disabled by the system library, the Auto Power OFF function
(APO) is also disabled. This is because both the power management function and Auto Power OFF
function use the same activity processing routine.
Touch panel
No activity for
Key
a specified period
COM1
of time
File access
Touch panel
Generation of
Key
Activity
COM1
File access
Fig. 2.8
33
DOZE
Low speed