M16C30_02 Datasheet, PDF (42/178 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Power control
Mitsubishi microcomputers
M16C / 30 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Power control
The following is a description of the three available power control modes:
Modes
Power control is available in three modes.
(a) Normal operation mode
• High-speed mode
Divide-by-1 frequency of the main clock becomes the BCLK. The CPU operates with the BCLK.
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 with the BCLK. Each peripheral function operates according to its as-
signed clock.
• Low-speed mode
fC becomes the BCLK. The CPU operates according to the fC clock. The fC clock is supplied by the
subclock. Each peripheral function operates according to its assigned clock.
• Low power dissipation mode
The main clock operating in low-speed mode is stopped. The CPU operates according to the fC
clock. The fC clock is supplied by the subclock. The only peripheral functions that operate are those
with the subclock selected as the count source.
(b) Wait mode
The CPU operation is stopped. The oscillators do not stop.
(c) 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.
Figure 1.10.5 is the state transition diagram of the above modes.
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