Figure 27.1 Mode Transition Diagram - Renesas H8S/2158 User Manual

Reset state
Program execution state
High-speed mode
(main clock)
SCK2 to
SCK0 are
0
Medium-speed
mode
(main clock)
SLEEP instruction
SSBY = 1, PSS = 1,
DTON = 1, LSON = 0
After the oscillation
stabilization time
(STS2 to STS0), clock
switching exception
processing
Sub-active mode
(sub-clock)
Notes: When a transition is made between modes by means of an interrupt, the transition cannot be made
on interrupt source generation alone. Ensure that interrupt handling is performed after accepting the
interrupt request.
Always select high-speed mode before making a transition to watch mode or sub-active mode.
1. NMI, IRQ15 to IRQ0, KIN9 to KIN0, WUE15 to WUE8, and WDT1 interrupts
2.
NMI, IRQ15 to IRQ0, KIN9 to KIN0, WUE15 to WUE8, WDT0, WDT1, TMR0,
and TMR1 interrupts
3.
NMI, IRQ15 to IRQ0, KIN9 to KIN0, and WUE15 to WUE8 interrupts

Figure 27.1 Mode Transition Diagram

STBY pin = High
RES pin = Low
RES pin = High
SLEEP instruction
Any interrupt
SLEEP
SCK2 to
instruction
SCK0 are
not 0
External
interrupt *
Interrupt *
LSON bit = 0
SLEEP instruction
SSBY = 1, PSS = 1,
DTON = 1, LSON = 1
Clock switching
exception processing
SLEEP instruction
: Transition after exception processing
Section 27 Power-Down Modes
Program halt state
STBY pin = Low
standby mode
SSBY = 0, LSON = 0
(main clock)
SSBY = 1,
PSS = 0, LSON = 0
standby mode
3
SLEEP
instruction
SSBY = 1,
1
PSS = 1, DTON = 0
Watch mode
SLEEP
instruction
Interrupt * 1
SSBY = 0,
PSS = 1, LSON = 1
LSON bit = 1
Sub-sleep mode
Interrupt * 2
: Power-down mode
Rev. 3.00 Jan 25, 2006 page 779 of 872
Hardware
Sleep mode
Software
(sub-clock)
(sub-clock)
REJ09B0286-0300