Renesas Hitachi H8S/2191, Hardware Manual

Page: 94 / 1065

Rev. 2.0, 11/00, page 67 of 1037
Section 4 Power-Down State
4.1 Overview
In addition to the normal program execution state, this LSI 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.
This LSI 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. Standby mode
Of these, 2 to 8 are power-down modes. Certain combinations of these modes can be set.
After a reset, the MCU is in high-speed mode.
Table 4.1 shows the internal chip states in each mode, and table 4.2 shows the conditions for
transition to the various modes. Figure 4.1 shows a mode transition diagram.