M16C6KA_15 Datasheet, PDF (38/270 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER Description

M16C/6KA Group
Power control
Power control
The following is a description of the power control modes:
Modes
Power control is available in three modes.
(1) Normal operation mode
• High-speed mode
Divide-by-1 frequency of the main clock becomes the BCLK. The CPU operates with the internal clock
selected. Each peripheral function operates according to its assigned clock.
• Medium-speed mode
Divide-by-2, divide-by-4, divide-by-8, or divide-by-16 frequency of the main clock becomes the BCLK. The
CPU operates according to the internal clock selected. Each peripheral function operates according to its
assigned clock.
(2) Wait mode
The CPU operation is stopped. The oscillators do not stop.
(3) Stop mode
All oscillators stop. The CPU and all built-in peripheral functions stop. This mode, among the three modes
listed here, is the most effective in decreasing power consumption.
Fig.WA-4 is the state transition diagram of (1) to (3).
Transition of stop mode, wait mode
Reset
All oscillators stop
Stop mode
All oscillators stop
Stop mode
CM10 = “1”
Interrupt
Interrupt
CM10 = “1”
Medium-speed mode
(Divided-by-8 mode)
High-speed/medium-
speed mode
Normal mode
WAIT
command
CPU operation stop
Interrupt
Wait mode
WAIT
command
CPU operation stop
Interrupt
Wait mode
Fig.WA-4 State transition diagram of Power control mode
Rev.1.00 Jul 16, 2004 page 36 of 266
REJ03B0100-0100Z