HD64F2149 Datasheet, PDF (745/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

Section 24 Power-Down State
24.1 Overview
In addition to the normal program execution state, the H8S/2169 or H8S/2149 has a power-down
state in which operation of the CPU and oscillator is halted and power dissipation is reduced.
Low-power operation can be achieved by individually controlling the CPU, on-chip supporting
modules, and so on.
The H8S/2169 or H8S/2149 operating modes are as follows:
1. High-speed mode
2. Medium-speed mode
3. Subactive mode
4. Sleep mode
5. Subsleep mode
6. Watch mode
7. Module stop mode
8. Software standby mode
9. Hardware standby mode
Of these, 2 to 9 are power-down modes. Sleep mode and subsleep mode are CPU modes, medium-
speed mode is a CPU and bus master mode, subactive mode is a CPU, bus master, and on-chip
supporting module mode, and module stop mode is an on-chip supporting module mode
(including bus masters other than the CPU). Certain combinations of these modes can be set.
After a reset, the MCU is in high-speed mode and module stop mode (excluding the DTC).
Table 24.1 shows the internal chip states in each mode, and table 24.2 shows the conditions for
transition to the various modes. Figure 24.1 shows a mode transition diagram.
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