M30622MA-XXXFP RENESAS [Renesas Technology Corp], M30622MA-XXXFP Datasheet - Page 495

• Manufacturer Part Number: M30622MA-XXXFP
• Description: 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY
• Manufacturer: RENESAS [Renesas Technology Corp]

480
Controlling Power Applications
3.8 Controling Power Using Wait Mode
Overview
Specifications
Operation
Figure 3.8.1. Operation timing of controling power using wait mode
X
X
Timer B overflow
Timer B2
interrupt processing
INT
BCLK
CIN
OUT
0
The following are steps for controling power using wait mode. Figure 3.8.1 shows the operation
timing, and Figures 3.8.2 to 3.8.4 show the set-up procedure.
Use the following peripheral functions:
• Timer mode of timer B
• 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
(2) Clear wait mode if a INT0 interrupt request occurs.
(1) Switch the system clock from XIN to X
(2) Stop X
(3) When a timer B2 interrupt request occurs (at 1-second intervals), start supplying the BCLK
At this time, count the clock within the routine that handles the timer B2 interrupts and enter wait
(4) If a INT0 interrupt occurs, start supplying the BCLK from X
occur every one second, which is a count the timer reaches, the controller returns from wait
mode and count the clock using a program.
from X
mode again.
the INT0 interrupt, and switch the system clock to X
_______
_______
IN
“H”
“L”
CIN.
High-speed
and enter wait mode. In this instance, enable the timer B2 interrupt and the INT0 interrupt.
(1) Shift to low-speed mode
Low-speed
(2) Stop X
________
(3) Timer B2 interrupt
IN
Low-speed
CIN
CIN
to serve as the timer count source. As interrupts
to get low-speed mode.
IN
Low-speed
.
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
CIN
. Start the X
(4) INT
Low-speed
Mitsubishi microcomputers
IN
0
M16C / 62 Group
interrupt
oscillation within
High-speed
_______