Rev.2.00 Oct 16, 2006 page 325 of 354
REJ09B0340-0200
M30245 Group
3. Controlling Power Applications
3.9 Controlling Power Using Wait Mode
The following are steps for controling power using wait mode. Figure 3.9.1 shows the operation
timing, and Figures 3.9.2 to 3.9.4 show the set-up procedure.
Use the following peripheral functions:
• Timer mode of timer A
• Wait mode
A flag named “F-WIT” is used in the set-up procedure. The purpose of this flag is to decide
whether or not to clear wait mode. If F_WIT = “1” in the main program, the wait mode is entered;
if F_WIT = “0”, the wait mode is cleared.
(1) Connect a 32.768-kHz oscillator to X
CIN
to serve as the timer count source. As interrupts
occur every one second, which is a count the timer reaches, the controller returns from wait
mode and count the clock using a program.
________
(2) Clear wait mode if a INT0 interrupt request occurs.
(1) Switch the system clock from X
IN
to X
CIN
to get low-speed mode.
_______
(2) Stop X
IN
and enter wait mode. In this instance, enable the timer A2 interrupt and the INT0 interrupt.
(3) When a timer A2 interrupt request occurs (at 1-second intervals), start supplying the BCLK
from X
CIN.
At this time, count the clock within the routine that handles the timer A2 interrupts
and enter wait mode again.
_______
(4) If a INT0 interrupt occurs, start supplying the BCLK from X
CIN
. Start the X
IN
oscillation within
_______
the INT0 interrupt, and switch the system clock to X
IN
.
Overview
Specifications
Operation
Timer A2
interrupt processing
Timer A2 overflow
X
CIN
X
OUT
BCLK
INT
0
(1) Shift to low-speed mode
(2) Stop X
IN
(3) Timer A2 interrupt
(4) INT
0
interrupt
“H”
“L”
High-speed
Low-speed
Low-speed
Low-speed
Low-speed
High-speed
Figure 3.9.1. Operation timing of controling power using wait mode
Содержание M16C FAMILY
Страница 12: ...Chapter 1 Hardware...
Страница 13: ...See M30245 group datasheet...
Страница 14: ...Chapter 2 Peripheral Functions Usage...
Страница 303: ...THIS PAGE IS BLANK FOR REASONS OF LAYOUT...
Страница 304: ...Chapter 3 Examples of Peripheral Functions Applications...
Страница 340: ...Chapter 4 External Buses...
Страница 361: ...THIS PAGE IS BLANK FOR REASONS OF LAYOUT...
Страница 362: ...Chapter 5 Standard Characteristics...
Страница 369: ...1753 Shimonumabe Nakahara ku Kawasaki shi Kanagawa 211 8668 Japan M30245 Group REJ09B0340 0200 User s Manual...